Cell Phone Based Remote Home Control System
Cell Phone Based Remote Home Control System
May-06-13
Final Report
Client:
ECpE Department
Advisor:
Prof. Ahmed Kamal
Team:
Adam Mohling (CprE)
Chau Nguyen (EE)
Issa Drame (EE)
Arturo Palau (EE) (1st semester only)
REPORT DISCLAIMER NOTICE
DISCLAIMER: This document was developed as a part of the requirements of an electrical and computer engineering course at Iowa State University, Ames, Iowa. This document does not constitute a professional engineering design or a professional land surveying document. Although the information is intended to be accurate, the associated students, faculty, and Iowa State University make no claims, promises, or guarantees about the accuracy, completeness, quality, or adequacy of the information. The user of this document shall ensure that any such use does not violate any laws with regard to professional licensing and certification requirements. This use includes any work resulting from this student-prepared document that is required to be under the responsible charge of a licensed engineer or surveyor. This document is copyrighted by the students who produced this document and the associated faculty advisors. No part may be reproduced without the written permission of the senior design course coordinator.
Submission Date
May 3, 2006
Table of Contents
1. Introductory Materials 1
1.1. Executive Summary 1
1.2. Acknowledgements 3
1.3. Problem Statement 3
1.3.1. General Problem Statement 3
1.3.2. General Solution Approach 3
1.4. Operating Environment 3
1.5. Intended Users and Intended Uses 4
1.6. Assumptions and Limitations 4
1.6.1. Assumptions List 4
1.6.2. Limitations List 5
1.7. Expected End Product and Other Deliverables 5
2. Approach and Product Design Results 6
2.1. Functional Requirements 6
2.2. Design Constraints 7
2.3. Approaches Considered and One Used 8
2.3.1 Considered Cellular Modules 8
2.3.2 Considered AC/DC interfaces 11
2.3.3 Considered Microcontrollers 12
2.4. Detailed Design 28
2.5. Implementation Process Description 39
2.6. Testing of the End Product and Results 42
2.7. End Results of the Project 47
3. Resources and Schedule 48
3.1. Estimated Resource Requirements 48
3.1.1. Personnel Resources 48
3.1.2. Financial Requirements 51
3.2. Schedules 54
4. Closure Materials 60
4.1 Project Evaluation 60
4.2 Commercialization 63
4.3 Additional Work 63
4.4 Lessons Learned 64
4.5 Risk and Management 65
4.6 Project Team Information 68
4.7 Closing Summary 69
4.8 Reference: 69
4.9 Appendix 69
List of Figures
Figure 1 – Overall System Flow Diagram 2
Figure 2 – GM28 Cellular Module 10
Figure 3 – STK300 Starter Kit 18
Figure 4 – Bracket Coding Standard 22
Figure 5 –Thermostat Control Schematic 32
Figure 6 - Thermostat Application Module Schematic Diagram 33
Figure 7 –Fan Control Schematic 36
Figure 8 – Fan Status Signal Circuit Schematic 37
Figure 9 – Light Schematic 38
Figure 10 – Decode LCD Display Matrix 41
Figure 11 – Original Project Schedule Summary 54
Figure 12 – Current Project Schedule Summary 54
Figure 13 – Original Project Reporting Schedule 55
Figure 14 – Design Report Project Reporting Schedule 56
Figure 15 – Final Project Reporting Schedule 57
Figure 16 – Project Development Schedule 58
Figure 17 – Final Project Development Schedule 59
List of Tables
Table 1 – STK200 Starter Kit 13
Table 2 – STK300 Starter Kit 15
Table 3 – Freescale MC68HC11E9 Starter Kit 16
Table 4 – Philips 51 Plus Starter Kit 17
Table 5 – Personal Effort in Hours 49
Table 6 – Financial Requirements 52
Table 7 – Detailed Circuit Financial Requirements 53
List of Definitions
DTMF (Dual-Tone Multi-Frequency) – used for telephone signaling over the line in the voice frequency band to the call switching center.
GSM (Global System for Mobile Communications) – a cellular communication network standard.
GPRS (General Packet Radio Service) – a mobile data service offered to GSM mobile users.
M2M (Machine to Machine) – concept of communications between a device containing some amount of data and another device that requires the use of that data.
SMS (Short Message Service) – a service available on most digital mobile phones that permit the sending of short messages (also known as text messaging service).
GCC Compiler – C language compiler that is used to compiling C language source code.
1. Introductory Materials
This section is intended to give an overview of the project. Some of the questions answered in this section include what the project is about, what problems it will address, what solutions it will implement to resolve those problems, and who the intended users are.
1. Executive Summary
This document outlines the May06-13 senior design team’s plan for designing and developing a cell phone based remote home control system.
The system allows a user to control selected devices from a cellular phone and will be broken down in three main parts: The cellular phone (serving as a platform for instructions and as a device status interface), the control unit (receiving, interpreting and issuing commands), and the controlled devices. The control unit will comprise a cellular module and a microcontroller.
The basic device control scenario will start at the cellular phone, where the user will input a command in the form of an SMS text message. At the control unit, the cellular module will receive the command and transmit it to the microcontroller. The microcontroller will then interpret the command and issue the appropriate control signal to the device to be operated. After the command is executed, the control unit will send a completion status message back to the cellular phone.
The main components of the control unit will be the Sony Ericsson GM28 for the cellular module and the Atmel STK300 Starter Kit for the microcontroller. The three controlled devices will be the Zilog Thermostat Application Module kit, a Honeywell HT-800-19 fan, a light and the microcontroller programming will be done in C programming language.
The team has spent a total of 741 hours and at a rate of $10.30 per hour the labor cost is $7632.30. With a cost of $148.91 on parts and materials, the total cost for the project is $7881.21 including labor. The team ended up under budgeting the project by $1184.50. In terms of parts, the team’s microcontroller starter kit and the cellular module were donated by their respective manufacturers. This kept the actual total cost at approximately half what it would have ended up costing.
The entire flow of data throughout the system is shown in figure 1.
[pic]
Figure 1 – Overall System Flow Diagram
2. Acknowledgements
Special thanks are extended to Professor Ahmed Kamal for his support and mentorship towards the development and success of this project.
3. Problem Statement
The problem statement is broken into two sections: a general problem statement and a general solution approach. This section will define in general what some of the problems this project will attempt to solve using general solution approached.
1. General Problem Statement
The objective of this project was to develop a device that allowed for a user to remotely control and monitor multiple home appliances using a cellular phone. This system is a powerful and flexible tool that’s service is always available, and from any location with the constraints of the technologies being applied. Possible target appliances include (but are not limited to) climate control systems, security systems, lights, and any appliance that can be controlled through an electrical interface.
2. General Solution Approach
The approach used for designing this system was to implement a microcontroller-based control module that receives instructions and commands from a cellular phone over the GSM network. The microcontroller then carries out the issued commands and sends the status of a given appliance or device back to the cellular phone. For security purposes, a means of identification and user authentication will be implemented, and will combine caller identification with a password authorization.
3. Operating Environment
The control system will include two separate units: the cellular phone, and the control unit. There will therefore be two operating environments. The cellular phone will operate indoors and outdoors whereas the control unit will operate indoors within the temperature and humidity limits for proper operation of the hardware.
4. Intended Users and Intended Uses
This product is aimed toward average consumers who wish to control household appliances remotely from their cell phones provided that the appliances are electrically controllable. Example of feasible appliances and applications under consideration include; enable/disable security systems, fans, lights, kitchen appliances, and adjusting the temperatures settings of a heating/ventilation/air conditioning system.
5. Assumptions and Limitations
This section lays out the assumptions and limitations of the project.
1. Assumptions List
Following are the assumptions made by the team:
• The user and control unit will establish communication via GSM
• The cell phone and service provider chosen will support text messaging service
• The user is familiar with text messaging on their cell phone
• The cell phone will support storing text message templates within the cell phone’s memory
• All service charges from service provider apply
• The controlled appliances will have to have an electrical interface in order to be controlled by microcontroller
• The audience reading this document will have a familiarity with engineering terms
• All measurements for temperature will be on Fahrenheit scale
• A pre-paid cell phone and sim card will be used for connectivity to a GSM network
• The ability to send and receive messages is possible through C programming and the use of the gcc compiler.
• Through the use of C programming, the microcontroller should be able to send messages and decode received messages
• The thermostat’s driver is always properly functioning, as it is essential to decoding the display.
2. Limitations List
Listed below are client-specified limitations:
• The receiver must reside in a location where a signal with sufficient strength can be received from a GSM network
• The only person who can communicate with the control module is the person who will be successfully authenticated
• Only devices with electrical controlling input ports will be possible targets for control
• System will be installed in a household climate
• The controlled devices will have I/O ports that will make communication with the receiver possible
• The receiver must have a power source (120V) attached at all times
• Operation of the control unit is only possible through a cell phone with SMS messaging capabilities
• The control unit must be able to receive and decode SMS messages.
• If the microcontroller is not able to send or receive messages, the functionality of the system will be greatly compromised
• The thermostat’s data bus is internal to its CPU and unavailable to be decoded.
6. Expected End Product and Other Deliverables
The following is a list of expected end products and other deliverables:
• A single M2M controller module that can perform the following:
o Receive and parse command instructions from a messaging device on a communication network
o Monitor a device status from an electronic interface
o Control target devices through an electrical interface
• A list of approved message input commands that the device is capable of executing
• Develop a user manual for reference by the end user
• A project plan and this design document will be written to defined and outline project approaches and deliverables
• Project poster is required to showcase the project to students and faculty members
• Design document is required to outline the technical requirements and system’s functionalities
• Final report is required for documentation on the overall project, including; end results, success, failures, etc.
2. Approach and Product Design Results
The approach that will be taken by the team and the step-by-step process of the design of the end-product are described in this section. Some of the major portions of this project and course include the various requirements defined by the team for this project’s successful completion and the detailed explanation of the different project execution phases.
1. Functional Requirements
The following defines exactly what the product should and should not do:
• The control unit will have the ability to connect to the cellular network automatically.
• The control unit will be able to receive text messages and will be able to parse and interpret text messages for password identification and instructions to be sent to the microcontroller.
• The microcontroller within the control unit will issue commands to the electrical appliances through a simple control circuit.
• The control unit will control the electrical appliances and detect the status of the appliances to be relayed back to the microcontroller.
• The microcontroller within the control unit should be able to send status messages back to the cellular phone through the cellular network.
• The system should provide user authentication through cell phone number identification and/or password verification contained within the (SMS) text message.
2. Design Constraints
This section outlines the design constraints of the product. This section is derived from the assumptions and limitations list, functional requirements and other decisions made by the team members.
1. The control module will need to be shielded against electrostatic discharges. This will increase reliability of the system.
2. The user must have connectivity to the GSM network and any communication with the system will be in the form of text messaging. If the user does not have a useable sim card to place into the GM28 cellular module, then the system will not be able to receive user data. Without connectivity to the GSM network the system will be inoperable.
3. Only devices that can be controlled or monitored via electrical (non-mechanical) means are possible candidates for use in this system. There are no moving parts associated with this system. All moving parts are to be incorporated with our system and interfaced via electrical I/O pins.
4. The system will not provide power to the controlled devices. The controlled devices must be connected to a 120V power source along with the GM28 and the microcontroller.
3. Approaches Considered and One Used
This section discusses the various software technologies and the technical approaches that the team has researched in the process of deciding which tools and methods to adopt prior to the implementation phase.
1. Considered Cellular Modules
Part Number: GM47/48
Pros: The following are the attributes that are desirable about this cellular module
• 850/1900 MHZ operating frequencies
• Low power usage 3.4-4V at 250mA voice and 350mA data.
• RS232 connection available
• Universal developers’ kit available
• Interface with SIM detection module
• Controlled via AT commands
Cons: The only product attribute that makes it less desirable in comparison to other products is that the RS232 connection is through a 60 pin board on board connection, making it necessary to solder. Heat from soldering with a mere iron instead of industrial means may damage circuitry on the module.
Part Number: GM41/42
Pros: The following are the attributes that are desirable about this cellular module
• 850/1900 MHZ operating frequencies
• Low power usage 5V+-10% at 250mA voice and 350mA data
• C source code libraries available
• Controlled via AT commands
• 40 pin DIP connection
Cons: The only attribute that makes this product less desirable in comparison to other products is the higher power usage. The same current is drawn, but at a higher voltage level than that of other modules.
Part number: GM28/29
Pros: The following are the attributes that are desirable about this cellular module
• 850/1900 MHZ operating frequencies
• Integrated SIM card holder
• RS232 via DB9 connector
• Easily programmable in C language
Cons: The only attribute that makes this product less desirable in comparison to other products is the higher voltage usage 5-32V. Current value specifications of this module are not available but presumed comparable to other modules.
Part Number: GR47/GR48
Pros: The following are the attributes that are desirable about this cellular module
• 850/1900 MHZ operating frequencies
• Low power usage 3.4-4V at 250mA voice and 350mA data
• Controlled via AT commands
• Universal Developers’ kit available
Cons: The only attribute that makes this product less desirable in comparison to other products is that the RS232 connection is through a 60 pin board on board connection, making it necessary to solder. Heat from soldering with a mere iron instead of industrial means may damage circuitry on the module.
Part Number: EE54 Edge
Pros: The following are the attributes that are desirable about this cellular module
• 850/1900 MHZ operating frequencies
• USB 2.0 connection
• Controllable via AT commands
• Universal Developers’ kit available
• On board SIM card holder
Cons: The only attribute that makes this product less desirable in comparison to other products is the higher power usage compared to other products at 5.5-20V and 250mA voice and 350ma data.
Part Number: CM52
Pros: The following are the attributes that are desirable about this Cellular module
• 850/1900 MHZ operating frequencies
• 40 pin DIP Connector
• Controllable via AT commands
• Universal Developers’ kit available
Cons: The only attribute that makes this product less desirable in comparison to other products is the higher power usage compared to other products at 5.5-13.8V and 1A.
Final selection: GM28 Cellular Module
Figure 2 – GM28 Cellular Module
Reason for Selection
The GM28 cellular module was chosen for several reasons. For one, it comes with an internal SIM card reader and has a DB9 RS232 serial connection making communication more reliable and eliminating the need for soldering connections directly to the module. The $600 developer’s kit is not necessary for this entirely enclosed device.
2. Considered AC/DC interfaces
Two technologies were considered for the implementation of fan and light controls: CMOS based gates and relays. Their pros and cons were evaluated and a decision was made based on the evaluation.
CMOS based logic gates
Pros:
• Fast switching
• No static power dissipation
• Voltage levels are compatible with that of a microcontroller
• Inexpensive
Cons:
Low voltage levels of operation make the CMOS incompatible with 120Volts AC
Relays
Pros:
Control high voltage circuitry using low voltages; therefore compatible both with the fan and light’s power supply circuitry and the microcontroller’s circuitry
Cons:
• Higher cost than CMOS integrated circuits
• Some types or relays dissipate static power
Selected Technology:
Relays were chosen in this case due to the sole fact that their main advantage of being compatible with both the microcontroller’s logic voltage levels and 120 VAC circuitry is not available with CMOS gates.
3. Considered Microcontrollers
Functionality requirements for microcontroller include; the ability to receive and parse text messages from GSM module, carry out the required commands, monitor appliance status information, and send status back to the GSM module. Since a microcontroller alone would not be sufficient, considerations of microcontrollers will be done through a microcontroller starter kit. The implementation of the microcontroller into the project design should be done economically and as efficiently as possible. The following is the list of microcontroller starter kits under consideration
Table 1 – STK200 Starter Kit
|STK200 Starter Kit by Kanda |
|Compatible Microcontroller |
|ATtiny12 |AT90S1200 |ATmega48 |
|ATtiny13 |AT90SS2313 |ATmega8 |
|ATtiny15 |AT90S2343 |ATmega88 |
|ATtiny22 |AT90S2333 |ATmega8515 |
|ATtiny2313 |AT90S4414 |ATmega8538 |
|ATtiny26 |AT90S4433 |ATmega16 |
| |AT90S8515**(8K bytes in-system |ATmega161 |
| |programmable Flash) | |
| |AT90S8535 |ATmega162 |
| | |ATmega163 |
| | |ATmega168 |
| | |ATmega32 |
| | |ATmega323 |
|Board Features |
|Cable/Connection |ISP and RS232 |
|Power Consumption |9-15VDC or 7-12VAC |
|I/O |64-pins |
|Highlights |Sockets for various devices 1x8,2x20, 1x28, 2x40 pin socket device to |
| |support all device pin-outs |
| |Port Headers includes Vcc and Ground for powering external circuitry |
| |8-way bar LED , 8 Switches |
| |3.3V/5V voltage selection |
| |Brownout (2.9V or 4.5V level) |
| |ADC circuitry |
| |External Memory for 74HC573 address latch and Flash RAM sockets |
| |EEPROM socket for 24C |
| |Includes AT90S8515-8PC microprocessor |
|Accompanied Development Software |
|Minimum hardware and software |80386 Processor (486 Recommended) |
|requirements | |
| |1 MB Ram |
| |1 MB Free Hard Disk Space |
| |Windows 3.1 or Windows 95 (minimum requirement) |
|Software |Application Builder |
| |AVR Studio 3 and 4 |
| |AVREdit and AVRGCC |
|Price |$66 |
Pros:
The advantage of using the STK200 starter kit is that the kit is compatible with a variety of 8-bit, 16-bit, and 32-bit Atmel AVR microprocessors. The kit also makes it easily interchangeable between devices with 1x8, 2x20, 1x28, 2x40 pins digital sockets. Port B-E headers of the development board contain Vcc and Ground pins which can be utilized to drive external circuitries and contain 8 I/O pins each.
Programming should be very unproblematic because the Application Builder software included with the kit will allow the user to efficiently setup code for ports, timers, UART, ADC, SPI, watchdog and interrupts. AVR Studio 4 is a full editor, assembler and simulator of all AVR devices and AvrEdit and AVRGCC allow the utilization of C programming language in the development process. Other highlights of the kit include communication via RS232, brownout circuitries, sufficient I/O ports, and expandability with external RAM, Flash, and EEPROM sockets.
Cons:
The main disadvantage is that the AT90S8515-8PC microcontroller included with the kit is an 8-bit microcontroller with 8K bytes in-system programmable flash memory, which might be insufficient memory allocation for project feasibility. Another disadvantage is that the clock speed runs by default at 8MHz, given a 2.7V power supply and is advertised to run at 16MHz at 5V, but that fact is not guaranteed by Atmel.
Table 2 – STK300 Starter Kit
|STK300 Starter Kit by Kanda |
|Compatible Microcontroller |
|ATmega103 |
|ATmega603 |
|ATmega128**(128K bytes of in-system programmable Flash, 4K bytes of in-system programmable EEPROM and 4K bytes of |
|SRAM) |
|Board Features |
|Cable/Connection |ISP and RS232; opt. USB |
|Power Consumption |9-15VDC or 7-12VAC |
|I/O |Port A-E (8-pins I/O; Vcc and Gnd); Analog Port F(8 analog pins; analog Gnd and Ref);|
| |Misc. Header; 66-pins total |
|Highlights |Port Headers includes Vcc and Ground for powering external circuitry |
| |8-way bar LED , 8 Switches |
| |3.3V/5V voltage selection |
| |Brownout (2.9V or 4.5V level) |
| |LCD's connectors |
| |Drop-in external RAM, with sockets for Address Latch chip and RAM plus dip header |
| |Include daughter board with Atmega128 microcontroller |
|Accompanied Development Software |
|Minimum hardware and software |80386 Processor or Above |
|requirements | |
| |1 MB Ram |
| |1 MB Free Hard Disk Space |
| |Windows 3.1 or Windows 95 (minimum requirement) |
|Software |STK300 Application Builder |
| |AVR ISP (C-complier) |
| |AVR and IAR Studio are available for download at Atmel website |
|Price |$85 |
Pros:
The development board for this kit contains the same features and functionalities as the STK200 development board, but has been modified so it is compatible with AVR Mega microcontrollers. The main advantage of this implementation is that larger projects are now feasible with the incorporation of AVR Mega microcontrollers. Included with the kit is ATmega128L-8AI microcontroller containing 128K bytes of in-system programmable Flash, 4K bytes of in-system programmable EEPROM and 4K bytes of SRAM. This is sufficient memory allocation for project feasibility. Since the microcontroller chips are surface mounted on a daughter board, problems with surface mounting the device can be avoided. Other advantages and highlights with STK300 are similar to advantages and highlights with STK200.
Application Builder is also included with the kit. Also included in the kit is AVR ISP software that supports programming via PC’s parallel port. Programming through PC’s serial port is still possible with this kit. AVR and IAR Studio are available to be downloaded from Atmel websites. AVR Studio allows easy development and debugging with its built in assembler and simulator.
Cons:
The main disadvantage of this kit is the microcontroller is not as easily interchangeable as SKT200 because the new device has to be soldered on the daughter boards first. Another disadvantage is that the STK200 supports more microcontrollers than the STK300.
Table 3 – Freescale MC68HC11E9 Starter Kit
|Freescale (Motorola) MC68HC11E9 Starter Kit |
|Compatible Microcontroller |
|MC68HC11E9 (12K Flash/EPROM; 512 RAM; 512 EEPROM; 38 I/O) |
|Board Features |
|Cable/Connection |PC COM port |
|Power Consumption |7-18VDC |
|I/O |38-pins |
|Highlights |3"x1.5" Solderless Breadboard |
| |Prototype Area |
| |8MHz crystal |
| |LCD's connectors |
| |Keypad connectors |
| |U5: 32Kbytes RAM installed |
| |U7: 8Kbytes EEPROM installed |
| |U6: expandable slot for RAM, EPROM, and EEPROM |
| |Buffalo Monitor utility for debug and test program |
|Accompanied Development Software |
|Minimum hardware and software |DOS or Win 3.1 |
|requirements | |
|Software |AXIDE |
| |free Assembler, C compiler and example source code |
|Price |$99 |
Pros:
The main advantage of Freescale (Motorola) MC68HC11E9 Starter Kit
Is that it has a solderless breadboard area and prototype area that can be easily utilized for prototyping circuits as well as driving different circuit components. The MC68HC11E9 microcontrollers with the installed 32K bytes external RAM and 8K bytes external EEPROM will provide sufficient memory allocation for project feasibility. Program will be stored in 32K bytes RAM to be tested and debugged by Buffalo Monitor utility. Other advantages include program in assembler and C, sufficient I/O ports, and expandable slots.
Cons:
The main disadvantage of Freescale (Motorola) MC68HC11E9 Starter is its price is considerably higher then the previous starter kits. Another disadvantage with this starter kit is that it does not allow interchangeability among different microcontroller since the MC68HC11E9 microcontroller is surface mounted onto the development board.
Table 4 – Philips 51 Plus Starter Kit
|8051 Starter Kit Philips XA/RD/66x |
|Compatible Microcontroller |
|P89C51RB2(H) |P89C660 |XA-G49** (64K bytes Flash; 2K RAM) |
|P89C51RC2(H) |P89C662 | |
|P89C51RD2(H) |P89C664 | |
| |P89C668 | |
|Board Features | |
|Cable/Connection |Serial | |
|Power Consumption |9-15V AC or DC | |
|I/O |32 I/O ports | |
|Highlights |40-pin DIP | |
| |44-pin PLCC sockets | |
| |External RAM circuitry | |
| |LCD connection | |
| |switches and 10-way Bar | |
| |LED | |
|Accompanied Development Software |
|Minimum hardware and software |Win 95 |
|requirements | |
|Software |Application Builder |
| |WINISP and Flash Magic Programming Tools |
| |C-compiler Demos (4K max) and Simulator |
|Price |$94.80 |
Pros:
The main advantage of this kit is that the XA-G49 microcontroller chip that is included with match project feasibility. This will mean more functionality and expandability for the project. Other highlights of the kit include sufficient I/O ports for project feasibility and external RAM circuitry.
Cons:
The main concern with this kit is it the XA-G49 does not contain any EEPROM memory and could be problematic if the project functionality requires the use of EEPROM. The other concern is the C-compiler included in the kit is only a demo version, with coding limited to 4K bytes. This will limit the utilization of C programming language and the efficiency of the coding process.
Microcontroller selected: STK300 Starter Kit
After reviewing all of the microcontroller starter kits under consideration, the team selected STK300 Starter Kit to be the optimal choice.
Figure 3 – STK300 Starter Kit
Reason for Selection
The team decided to proceed with the STK300 Starter Kit because it has all functionalities of other microcontroller starter kits and it is the most economical. The STK300 Starter Kit allows larger projects compared to other starter kits to be implemented with the ATmega128 microcontroller included with the kit. It also allows flexibility with an interchangeable microcontroller design. It has a sufficient number of I/O ports for the project and it has a unique feature that allows the port headers to drive external circuitry with Vcc and Gnd pins. Coding process with this board will be efficient because it allows coding in higher level programming languages C and Application Builder allows wizards to set up ports, timers, UART, ADC, SPI, watchdog and interrupts. It is the most economical because the list price is less than the Freescale (Motorola) MC68HC11E9 Starter Kit and Philips 51 Plus Starter Kit.
4. Programming Language Considerations
There are many available software technologies that can be used to develop this project. In order to ensure that the team will create the best product to their abilities, all software solutions will be considered and evaluated by the team.
The files that will be developed in the selected development environment will then be ported over to the complier supported by selected microcontroller.
Programming in Assembly Language
Assembly language programming is very low level and will allow for more control of the source code. By using the assembly language, the complied code will take up less space when stored into the microcontroller’s memory. A majority of the team has programmed in assembly before in other courses taken at Iowa State University and is familiar with the language. Assembly also has a very quick response time.
Assembly language programming could prove to be more complex to implement. Many of the team members whom have taken it before will need to re-learn the language. There has yet to be an example of SMS assembly language code or any programming libraries discovered by the team from available resources that can be used to assist in developing knowledge for this project. The team would have to interface the assembly program code with some other language’s already defined libraries.
Programming in C Language
There are many examples available that the team has already located. The C programming language is a universally reliable language with many resources available for coding and debugging purposes. There are C libraries already written and available for interfacing with the GSM network and serial communication channel. All team members are familiar with C++ which is similar to this programming language, shortening the learning curve.
Programming in C++ Language
A definite advantage of programming in C++ is that all the group members have programmed with it before. C++ is also an object-oriented language, making development easier and allowing for multiple developers to create code and import changes into the final program. The response time of C++ will be at least as fast as interpreted languages.
The only disadvantage to using C++ is that GSM and serial communication libraries are more difficult to locate compared to the C programming language.
Programming in JAVA Language
Java is a very high-level programming language with many online and learning resources available to the team. Java also has a lot of built-in functions available to the developer. There are a number of disadvantage associated with this programming language. One is that a majority of the team members have never developed in Java. This would create a problem of not being able to utilize all team members for debugging, developing, or testing the Java code. Another disadvantage is that the final compiled code will take up more memory than other lower-level languages stated above. Finally, response time of the Java programming language is poor and would cause a lag in real-time execution.
Selected Programming Language: C
The team has decided to use the C programming language to develop this project.
Reason for Selection
The main reason for this selection is due to the number of online resources available to the team. Team members all have a good basis in developing in C++ so the main hurdle will be identifying the differences between using C instead of C++. This programming language is also supported by the team’s selected microcontroller.
5. Development Environments Considered
This section discusses the various coding development environments the team discussed for the coding phase of the project.
Eclipse
The Eclipse software is a very powerful Java-based open-source development environment. Its original intent is to be used as a Java developing environment, but there is a C/C++ plug-in that can be installed making it work with these languages.
The Eclipse software allows a developer to view the value of variables on-the-fly and step through code line-by-line. This is very valuable when it comes to debugging and troubleshooting.
The performance of this software can sometimes be very poor due to the nature of the Java virtual machine (JVM). However, since it is programmed in Java, the tool can be used on any machine that can support a JVM.
Visual Studio .NET 2003
This tool is developed and supported by the Microsoft Corporation. Similar to Eclipse, this software is free to the team through MSDNAA. This software also includes a complete range of capabilities from modelers that aid in visually composing the most complex of enterprise-class applications to deploying an application on the smallest of devices. Visual Studio .NET 2003 is widely used across the world.
Selected Developing Environment: Visual 2003
The team has decided to use the Visual Studio .NET 2003 developing environment to develop this project.
Reason for Selection
The main reason for this selection is that this resource can be obtained by all team members for free and is ready to start development without any additional work spent on setup by the team members.
6. Considered Coding Styles
This section discusses the various coding styles the team has discussed for the coding phase of the project.
Use of Brackets
All brackets will take up an entire line of code. The opening and closing of a bracket pairing will vertically line up in the same column of text at a tabbed position. Following an opening bracket, the preceding line of code shall be tabbed in to the next level. This coding style is apparent in Figure 4.
Figure 4 – Bracket Coding Standard
Variable Declaration
Since the decision of programming in the C language was chosen, all variables must be declared at the beginning of any and all functions. The variables shall be grouped together with similar variable types. For example, all integers shall be grouped together separate from all char, char*, etc.
Line Length
The number of characters per line shall be limited to 80 characters per line. The reason for this is for proper printing of all source code.
Function Declarations and Operations
The convention this team will use will be to not include any spacing between comparison operators or function elements. An example of this is shown in Figure 4.
7. Testing
Testing is separated into two major types: unit and integration. Unit testing is used to determine that a single component is functioning correctly while integration testing is used to determine that a newly-added component is functioning correctly within the context of the rest of the program.
The following unit testing requirements will be indicators that the system can successfully be implemented:
GSM Network Communication
The GSM receiver will be tested for successful communication with network. This will test include automation and consistency of the connection and will be conducted by a team member in the following way:
• The cellular phone will dial the GSM receivers’ number
• Once the connection is established a stream of data will be send to the GSM receiver.
• The GSM receiver will be given data to be transmitted to the cellular phone.
Success/failure criteria: The data received will be observed on both ends to verify its consistency. The test will be considered successful if the integrity of the sent and received data is maintained up/downstream. It will be considered a failure otherwise.
GSM to Microcontroller Communication
The GSM to microcontroller driver will be tested by verifying the integrity of command strings sent from the remote user. The following procedure will be performed in majority by a CprE team member:
• The remote user will send a command to the control module.
• The contents of the data stream will be observed at the GSM communication port.
• These contents will be compared with those received and stored at the microcontroller’s corresponding communication port.
• The procedure will be repeated in reverse with the microcontroller sending a data steam to the GSM receiver.
Success/failure criteria: The test will be considered successful if the integrity of the data sent up/downstream is maintained. It will be considered a failure otherwise.
GSM Message Decoding
Proper decoding of the remote user’s commands and issuance of the equivalent commands to the controlled device will be performed by team members using the following procedure:
• A simulated instruction will be fed to the microcontroller communication port.
• The output command at the I/O interface with the corresponding controlled device will be observed.
Success/failure criteria: The test will be considered a success if the resulting command issued from the microcontroller is sent to the right I/O address for the desired controlled device and if that command is consistent with the command which is expected. The test will be considered a failure otherwise.
Voltage Converter Circuit Operation
The scaling circuit from the controlled devices to the I/O will be tested for proper operation. This will be tested by EE team members:
• The controlled devices will be manually triggered to force the desired voltage.
• The output of the scaling circuit will be measured.
Success/failure criteria: The testing will be considered successful if the measured output voltage is properly scaled to the microcontroller’s required input value. The test will be considered a failure otherwise.
I/O Detection and Functionality
The ability of I/O to detect an input voltage and store a value in the microcontroller’s memory will be tested by team members:
• Test voltages to the input of the I/O will be applied.
• The contents of the memory shall be checked for validity.
Success/failure criteria: The testing will be considered successful if the values of the memory are as expected. The test will be considered a failure otherwise.
Power Surge Performance
The circuit’s power surge protection will be tested for acceptable performance by EE team members using the following procedure:
• The circuit’s power supply will be removed from the circuit and connected to a dummy load.
• A simulated voltage spike will be inputted by using a step signal from a signal generator.
• The output voltage and current will be measured at the load.
Success/failure criteria: The success of the test will be determined by verifying that the output signal to the dummy load falls with the tolerance indicated by the microcontroller and the GSM chip’s manufacturers. The test will be considered a failure if the measured characteristics of the power supply’s output do not meet the manufacturers’ requirements.
User Authentication
The password authentication will be tested for proper operation. The following procedure will be performed by team members:
• The password protection of the code will be run in debug mode.
• A simulated mix of correct and incorrect passwords will be sent to the microcontroller
• The response of the microcontroller will be observed for each of the inputted passwords.
Success/failure criteria: The testing will be considered successful if the microcontroller grants access to all the right passwords and none of the wrong passwords. The test will be considered a failure otherwise.
I/O Status Trigger Correctness
The ability of an I/O status to trigger the execution of status messaging subroutine will be tested as well as the ability to send the resulting status to the remote user. The following procedure will be performed by team members:
• A simulated device status will be written to the I/O in debug mode.
• The simulated status will trigger the execution of the microcontroller’s device status notification subroutine
• The subroutine output will be checked prior to being sent to the GSM chip.
• Verification that the status message was received by the user cell phone will be performed.
Success/failure criteria: The testing will be considered successful if the simulated I/O triggers execution of the subroutine and if the correct status message is sent to the GSM chip and that status message is received by the cell phone. The test will be considered a failure otherwise.
End Product Testing
The end-product functionalities will be tested by team members and non-team members in the following way:
• Team members will ensure that all subsystems function properly together from remote user command to execution and back to completion status notification.
• Non-team members from the general public will be allowed to access and use the control unit for a frame of time.
• Afterward, the non-team member testing subjects will fill out a survey on the end-product’s functionalities, ease of use, difficulties, etc.
Success/failure criteria: The testing will be considered a success if the testing subjects find the end-product user friendly, and easy to figure out.
Testers
Each team member is responsible for being the primary black box tester of a given member's code. Black box testers are to test code without examining the code itself in order to avoid having any assumptions outside of those specified by the conditions of the code.
Non-team members will be brought in to use the system and will be monitored by team members. If the non-team members cause an error in the system, the team members will document the nature of the error and address the issue as soon as possible.
4. Detailed Design
This section discusses the features and the design of the end product in depth. The discussion is based on the following sections:
Coding Details
There will be six main coding modules to the entire system. Five reside on the control unit located in the user’s home and the other module will reside on the user’s cell phone (*). They are:
• Initialization
• Check & Read Messages
• Decode Messages
• Application Control
• Status Monitoring
• Send Status Message
• Text Message Command Templates (*)
INITIALIZATION:
The initialization portion will require the following libraries in the project directory:
deftypes.h – Loads type definitions for string variable
RS232.h – Loads RS232 serial drivers
SerComm.h – Loads serial communication types
ATCommand.h – Loads AT commands for use
Include the entire EWMSDK library in the project:
AT Commands
PDU (Protocol Data Unit) Formatting
Serial Communication & RS232
AT_InitializeData
This is necessary when dealing with embedded systems in order to initialize memory upon startup. This function is used before initializing channels or registering events.
AT_CheckEvents / or Call AT_SetTimer (in Windows)
This will periodically search for events and will call AT_CheckEvents
MS_EstablishChannel
This function call will open the serial channel that will be used to communicate with the GSM chip. When communication with the GSM chip is complete, MS_ReleaseChannel will be called in order to keep the channel available for other applications.
CFG_SetCommandEcho (value parameter = 0)
EWMSDK will not work if ATE is set to 1.
VM_SetATResponseFormat (value parameter = 1)
This will enable verbose mode. The library requires ATV to be set to value 1 (ATV1) which is the usual state of modems. Doesn’t work in ATV0 mode.
CFG_SetReportEquipmentError (value parameter = 1)
This will allow the library to offer specific error code results returned by the module. There are 3 modes available: 0 and 2 will not interpret error codes, 1 will return error codes that can be referenced by the GSM module’s Integrator manual.
CHECK & READ MESSAGES:
The check and read messages coding module will use the following functions (descriptions of each are provided):
AT+CMGR=1
This will read only message #1 stored in the memory of the M2M module. If there is an incoming message, the message will be stored as a string. Messages can be deleted from the M2M module using the command AT+CMDG=1.
DECODE:
SMS messages contain information such as date, time, sender’s number and message. The program must perform simple string manipulations to decode this message and store all relevant data. If the decoded message is equal to a pre-stored message, then the function will be called for that particular command, otherwise it will be deleted.
Application Control:
The application control coding module will be used for sending commands to the microcontroller that will drive the I/O ports located on the microcontroller. These I/O ports will cause the controlled unit to perform the requested action.
Every application that is to be controlled will have its own separate function. When the function is called, it will drive the I/O ports on the microcontroller to perform the command requested.
Status Check:
The status check of all the devices will be slightly different for every device.
Every application that is to be controlled will also be monitored and will have its own separate function. The device is not required to be solely under the control of the system. This means that the system can not simply check the status of the I/O values to determine whether a device is in the state the system is applying. Additional hardware will need to be connected in order to determine the state of the device.
Send Status Message:
The send status message coding module will use the following function (description provided):
SMS messages will need to be sent back to sender with status of operation.
#Send message to phone number below
at+cmgs="destination phone number"
#Write your message at the “>” prompt. Hit Control-Z to send (do not hit enter to send)
>Test Message 1
Text Message Command Templates:
These text messages will be sent to the controlling unit located in the user’s home:
The cell phone message commands will have to be setup by the user. The entire list of acceptable messages can be found in Appendix C.
Microcontroller Details
The microcontroller will be the device controlling all the appliances. There will have to be special wiring for all devices connected to the microcontroller. The following section will show in detail how the team has discussed connecting the various devices to the microcontroller.
Thermostat Control:
[pic]
Figure 5 –Thermostat Control Schematic
Digital Thermostat Operation
[pic]
Figure 6 - Thermostat Application Module Schematic Diagram
Important components of digital thermostat:
• MAX6625 – 9-Bit/12-Bit temperature sensors with I2C-compatible serial interface.
• AT24C128 – Two-wire serial EEPROM
• 74HCT4052 – Dual 4-channel analog multiplexer, demultiplexer
• HEADER – Microcontroller
In Figure 6 the digital thermostat operates by constantly reading the room temperature and is connected to the multiplexer and the multiplexer is connected to the microcontroller. This means that the temperature sensor is sending the recorded temperature and the multiplexer then makes the signal more readable for the microcontroller. The microcontroller will decide, depending on the desired temperature, whether to turn on the A/C(cool down) or turn on the heater(warm up).
The thermostat also has three switches (S1, S2, S3) these are used to program different modes of operation or to change temperature set point. The controller is connected to an LCD that will either display the room temperature and the desired temperature and whether the fan is turned on or off. The EEPROM is used to store the temperature read by the temperature sensor. The operation of this thermostat is as follows:
1. The temperature sensor checks the room temperature every x seconds and sends the information to the microcontroller.
2. The microcontroller uses this information by comparing the room temperature to the desired temperature. There are two possible scenarios that will result – heat or cool the room.
• If the room temperature is under the desired temperature, the light bulb will turn on. This will heat up the temperature sensor until the temperatures are the same.
• If the room temperature is above the desired temperature the fan will turn on. This will cool the temperature sensor until the desired and room temperatures are equal.
Interface between Microcontroller and Thermostat
The microcontroller will use 3 pins from port A as outputs that will be connected to an XOR gate. The inputs to the XOR gate are one from the microcontroller and one from the pushbutton or the switch. These were selected so that the system can choose which signal are going to be use: either the one from the button or the one from the microcontroller. The XOR gate gives a “1” output only when the two inputs are different. Using this setup, only one will be controlling the input for the thermostat. The multiplexer from the thermostat, which sends the temperature, will be connected to both the microcontroller of the thermostat and the remote controlling system’s microcontroller. The thermometer will be sending the room temperature and the remote controlling system will both get it and use it to send to the user and other applications. This will also be connected to the output of the thermostat microcontroller that goes to the LCD so the desired temperature can be read and then determine how much the user wants to change the temperature (see the schematic in Figure 5).
How the Thermostat will Work
The control for the thermostat will work by having these messages and how they work:
• “thermo status” – this instruction will send the user the room temperature so the user can decide what he wants to do with that information. From this, the user will decide what action to take.
• “set thermo temp to XX” (desired temperature will go here) – this instruction will tell the microcontroller to change the desired temperature of the room to the new desired temperature.
• “thermo off” – this instruction will turn the A/C and the heater off, the fan (cooler) and the light bulb (heater) will be disconnected regardless of previous state.
Fan Control:
The control of the fan takes place at bits 0-3 of the STK300 kit’s port A. The main features of the fan control are the following:
• Manual/remote control
• Speed control
• Fan operating status detection.
The outlined features are implemented in the following way:
Manual/remote control select:
This part assumes that the microcontroller is powered on. Relay R3 is a single pole double throw relay. Its control signal comes from port A bit 3 of the STK300. This relay selects the output of either the fan switch or the control relays R1-R3 to be connected to ground. Its de-energized position is on the fan switch contact and its energized position is on the control relay contact. Therefore a logic signal of 0 corresponds to the default manual control and a logic signal of 1 corresponds to a remote control selection. In the case of loss of power or accidental reboot of the control module, the control returns to its default manual setting.
[pic]
Figure 7 –Fan Control Schematic
Speed control:
The fan’s manufactured speed control circuitry consists of a 4 position switch—of which 3 positions correspond to fan speeds and the 4th corresponds to the off position—and of three different size windings sharing a metal core with the rotor. The windings all share a common 120VAC voltage source and the switch selects either winding, allowing it to conduct to ground. The implemented speed control mimics this control system by connecting single pole single throw relays R0-R2 in parallel with each switch’s winding connection and the manual/remote select switch. R0-R2 is controlled by signals from bits 0-2 of port A of the STK300. For each switch the default/de-energized position is open circuit, and the energized position is closed circuit. Effectively the asserted bit selects the speed of the fan.
Device operating status detection:
The operating status of a device is determined by measuring a voltage drop across a very small resistor in series with the device load. The series resistor only decrease the normal power delivered to the device by 0.8%. The voltage across the series resistor is measured by an instrumentation amplifier corresponding on figure 8 to the first three operational amplifiers on the left. The signal is then rectified by a diode bridge and sent to an active op-amp based filter. The result is a dc signal with voltage level of 5 when the device is running and 0 when it is off. This signal is read at one off the control unit’s microcontroller I/O ports as a binary input.
Figure 8 – Fan Status Signal Circuit Schematic
Light Control:
The implemented control of a lamp essentially follows a similar design as the control of the fan. There is a single pole double throw relay controlling the selection of remote/manual operation and there is a single pole single throw relay in parallel with the light switch mimicking its function. The remote/manual selection relay is controlled by port B bit 1 of the STK300 and the on/off control relay is controlled by bit 0 of the same port.
[pic]
Figure 9 – Light Schematic
GSM Module Details
The GM28 cellular module is used to send and receive information over the GSM cellular network. There will not be any modifications to the GM28. The GM28 will be connected via RS232 serial communication port to the serial port on the STK300 microcontroller developer’s kit. See appendix A and B at the end of this document for the GSM and microcontroller images.
5. Implementation Process Description
The implementation process and materials used shall be described in this section. There were two main components to this project: hardware and software. Each of these components will be discussed separately. Upon completing discussion on both the hardware and software aspects, the integration of both parts shall be discussed and any problems encountered.
SOFTWARE
For the software, initial development was to be performed on a Microsoft Windows operating system. It was easier to perform the serial programming on a Unix-based system. There were several serial drivers available for download from the Internet. It was easier for the team do develop with Unix, so the development continued in the Unix environment.
The software ran into a problem when trying to send messages to the remote user. When using Microsoft Window’s hyper-terminal, it was possible to send the AT command ‘at+cmgs=”remoteUserNumber”’ then the system would prompt back with a prompt. At the prompt, the text message should be entered in and then submitted with “CTRL+Z”. During the coding implementation, the message ‘at+cmgs=”remoteUserNumber”’ was again sent. The system would again respond with the prompt but would however continue to prompt until eventually a PDU error resulted. The exact definition of the error is:
+CME 304 error: “invalid PDU format”
HARDWARE
The Implementation of the status detection was modified to accommodate the fact that successful application of power supply across a controlled devices does not ensure that the device is running. Current detection was chosen as the preferred means of verifying that a device is actually running. The initial design only measured the voltage applied across a controlled device as an indicator of the success of a control command, whereas the design included in this document measures the potential difference across a resistor which can only be due to running current in the controlled device.
The utilization of the STK300 microcontroller has been through the IDE that was included with the microcontroller kit. Code development took place in the C language and has been in developed in Notepad. After such, the code is then compiled into hex format using the avr-gcc.exe, which then can be loaded into the microcontroller. Debugging and simulation of the developed codes was in the AVR Studio 4 IDE environment. AVR Studio 4 also has the capability to do real-time in-circuit debugging which has made code development very efficient.
The difficulty the team encountered while working with the STK300 has been figuring out the configuration necessary so that the software can compile C languages. This problem was resolved after seeking help from Doug Oschner, a Senior Engineer at Maytag Corp. The team resolved this issue and was able to fully utilize C code on the microcontroller.
INTEGRATION
The software that was discussed previously was loaded onto the microcontroller and compiled. There had to be changes made to the software in order to function properly in the new environment. Utilization of the UART registers was necessary for transmitting and receiving data over the serial port. This meant that instead of writing to a file as is the case in a Unix environment, the team had to make this change. In addition, reading from the serial port required the team to check if the receive bit was high. This meant that the incoming buffer had data waiting. Instead of reading a line from the serial port, it was now necessary for the team to read and add to the string in 8-byte increments (this was the size of the I/O buffer).
The STK300 integration into the system is required for execution of various essential system functions. By utilizing the I/O pins of the STK300, the team can control various relays that would determine the different settings of controlled devices. The I/O pins are also used to detect the rectified voltages from the voltage status circuit to sense the status of the controlled device.
The STK300 also included a serial communication port that could send instructions and receive information from the GM28. To send instructions to the GM28, the STK300 sent out a string of predefined AT command that interfaced with the GM28. The receive information from the GM28 is stored into the buffer of the STK300, where it was parsed for authentication and command string. The command string initializes the proper function to be executed by the STK300 to either control devices or sense the status of a device.
To interface with the thermostat, a different approach will be utilized that differs from just controlling the relays. The team identified that the LCD for the thermostat has nine output pins. From these nine output pins, the team decoded the combination required to control each segment on the LCD’s display, see Figure 10.
[pic]
Figure 10 – Decode LCD Display Matrix
The signal from these output pins will go through a rectified circuit and the resulting rectified signal will be read from the I/O pins. After receiving the signal from the I/O pins, the microcontroller runs a function that decodes the signals and the LCD display from the thermostat can now be read. Reading the LCD display is crucial in controlling and monitoring the thermostat because the current temperature and temperature setting of the thermostat can now be received by the microcontroller. After gathering the necessary information from the thermostat, the microcontroller then controls the buttons of the thermostat via I/O pins to execute of the user’s command.
6. Testing of the End Product and Results
Testing is separated into two major types: unit and integration. Unit testing is used to determine that a single component is functioning correctly while integration testing is used to determine that a newly-added component is functioning correctly within the context of the rest of the program.
The following unit testing requirements will be indicators that the system can successfully be implemented:
GSM Network Communication
The GSM receiver will be tested for successful communication with network. This will test include automation and consistency of the connection and will be conducted by a team member in the following way:
• The cellular phone will dial the GSM receivers’ number
• Once the connection is established a stream of data will be send to the GSM receiver.
• The GSM receiver will be given data to be transmitted to the cellular phone.
Success/failure criteria: The data received will be observed on both ends to verify its consistency. The test will be considered successful if the integrity of the sent and received data is maintained up/downstream. It will be considered a failure otherwise.
GSM to Microcontroller Communication
The GSM to microcontroller driver will be tested by verifying the integrity of command strings sent from the remote user. The following procedure will be performed mostly by a CprE team member:
• The remote user will send a command to the control module.
• The contents of the data stream will be observed at the GSM communication port.
• These contents will be compared with those received and stored at the microcontroller’s corresponding communication port.
• The procedure will be repeated in reverse with the microcontroller sending a data steam to the GSM receiver.
Success/failure criteria: The test will be considered successful if the integrity of the data sent up/downstream is maintained. It will be considered a failure otherwise.
GSM Message Decoding
Proper decoding of the remote user’s commands and issuance of the equivalent commands to the controlled device will be performed by team members using the following procedure:
• A simulated instruction will be fed to the microcontroller communication port.
• The output command at the I/O interface with the corresponding controlled device will be observed.
Success/failure criteria: The test will be considered a success if the resulting command issued from the microcontroller is sent to the right I/O address for the desired controlled device and if that command is consistent with the command which is expected. The test will be considered a failure otherwise.
Voltage Converter Circuit Operation
The scaling circuit from the controlled devices to the I/O will be tested for proper operation. This will be tested by EE team members:
• The controlled devices will be manually triggered to force the desired voltage.
• The output of the scaling circuit will be measured.
Success/failure criteria: The testing will be considered successful if the measured output voltage is properly scaled to the microcontroller’s required input value. The test will be considered a failure otherwise.
I/O Port Manipulation and Detection
The ability of I/O to detect an input voltage and store a value in the microcontroller’s memory will be tested by team members:
• Test voltages to the input of the I/O will be applied.
• The contents of the memory shall be checked for validity.
Success/failure criteria: The testing will be considered successful if the values of the memory are as expected. The test will be considered a failure otherwise.
Power Surge Performance
The circuit’s power surge protection will be tested for acceptable performance by EE team members using the following procedure:
• The circuit’s power supply will be removed from the circuit and connected to a dummy load.
• A simulated voltage spike will be inputted by using a step signal from a signal generator.
• The output voltage and current will be measured at the load.
Success/failure criteria: The success of the test will be determined by verifying that the output signal to the dummy load falls with the tolerance indicated by the microcontroller and the GSM chip’s manufacturers. The test will be considered a failure if the measured characteristics of the power supply’s output do not meet the manufacturers’ requirements.
User Authentication
The password authentication will be tested for proper operation. The following procedure will be performed by team members:
• The password protection of the code will be run in debug mode.
• A simulated mix of correct and incorrect passwords will be sent to the microcontroller
• The response of the microcontroller will be observed for each of the inputted passwords.
Success/failure criteria: The testing will be considered successful if the microcontroller grants access to all the right passwords and none of the wrong passwords. The test will be considered a failure otherwise.
I/O Status Trigger Correctness
The ability of an I/O status to trigger the execution of status messaging subroutine will be tested as well as the ability to send the resulting status to the remote user. The following procedure will be performed by team members:
• A simulated device status will be written to the I/O in debug mode.
• The simulated status will trigger the execution of the microcontroller’s device status notification subroutine
• The subroutine output will be checked prior to being sent to the GSM chip.
• Verification that the status message was received by the user cell phone will be performed.
Success/failure criteria: The testing will be considered successful if the simulated I/O triggers execution of the subroutine and if the correct status message is sent to the GSM chip and that status message is received by the cell phone. The test will be considered a failure otherwise.
End Product Testing
The end-product functionalities will be tested by team members and non-team members in the following way:
• Team members will ensure that all subsystems function properly together from remote user command to execution and back to completion status notification.
• Non-team members from the general public will be allowed to access and use the control unit for a frame of time.
• Afterward, the non-team member testing subjects will fill out a survey on the end-product’s functionalities, ease of use, difficulties, etc.
Success/failure criteria: The testing will be considered a success if the testing subjects find the end-product user friendly, and easy to figure out.
Testers
Each team member is responsible for being the primary black box tester of a given member's code. Black box testers are to test code without examining the code itself in order to avoid having any assumptions outside of those specified by the conditions of the code.
Non-team members will be brought in to use the system and will be monitored by team members. If the non-team members cause an error in the system, the team members will document the nature of the error and address the issue as soon as possible.
7. End Results of the Project
The end result for each major components of the product will be summarized in this section. This will include expected to actual operation comparison of each system component and component satisfactory. Any significant accomplishments or research activities not covered elsewhere and major failures will also be documented in this section.
GM28:
The overall operation of the GM28 module matched the team expectation. The module was able established communication with the GSM network, receive SMS messages, and relay the received messages via serial port. The team is still in the process of researching how to utilize the sent message function on the GM28. Once this is established, the GM28 will then match all of the required criteria outlined in the Section 2.4.
Team members are satisfied for having chosen this module because it was compact, enclosed, and easy to interface.
STK300:
The STK300 has all the functionality outlined in Section 2.4. This includes I/O pins interface and serial communication capability. The AVR Studio 4 included allows the team to simulate the program before loading it onto the microcontroller and the JTAG kit included allows the team to do in-circuit debugging. These features will allow the team to code very efficiently. The team did not anticipate the amount of time required to set up the IDE software included with the kit to be compatible with C. This issue is now resolved.
Team members are satisfied for having chosen the STK300 because it is a versatile kit that has functionality far exceeds what was outlined by the design report. The kit also allows efficient programming because it has a simulation and in-circuit debugging capabilities.
Control Appliances:
The circuit designed for controlling the fan and the light in Section 2.4 was successfully implemented in lab work. The thermostat temperature was also successfully read by looking from the LCD output pins. The circuit for controlling the temperature setting of the thermostat still needs to be implemented. The major problem that the team encountered is in redesigning voltage detector circuit to a current detector circuit to be use as a status signal. This problem is due to having same ground for both AC and DC voltages and were resolved.
3. Resources and Schedule
This section includes an estimate of the resources required for the project. Resources defined include the number of hours each team member will spend on different project areas, any equipment that will be necessary for the project, and the total dollar amount that the team will need for successful project completion.
1. Estimated Resource Requirements
Personal hours and material costs make up the estimated resource requirements. There are three parts to each of these components: the original estimate, a combination of actual personnel hours to date and revised future personnel hours, and the actual hours. The original case shall be compared to the revised case and the reason(s) for the difference shall be explained.
1. Personnel Resources
Following is an update to the material presented in the same section of the project plan. This table outlines the projected and current hours spent by team members on the project as well as other resources hours to be spent on the project. Other resources are members of the general public that will be asked to use the system. The team is planning to use outside sources for testing in order to see if persons unfamiliar with the project will try to perform operations not accounted for by the team. The problem definition and technology considerations are complete, so the times reflected will not change.
Table 5 – Personal Effort in Hours
| |
|Adam Mohling |
|Adam Mohling |
|Adam Mohling |6 |13 |
|Original Projection |
|Parts and Materials | | |
|Computer Hardware & Software |$0.00 | |
|Final Project Enclosure |$3.00 | |
|M2M GSM Controller |$140.00 | |
|Misc. Electronic Components |$8.00 | |
|Poster |$50.00 | |
|Subtotal |$201.00 |$0.00 |
| |
|Labor (at $10.30/hr) | | |
|Adam Mohling | |$1895.20 |
|Chau Nguyen | |$1751.00 |
|Issa Drame | |$1771.60 |
|Arturo Palau | |$721.00 |
|Subtotal |$0.00 |$6138.80 |
|Total | |$6339.80 |
|Projected Total Cost |
|Parts and Materials | | |
|Misc. Electronic Components |$8.00 | |
|GM28 GSM Cellular module |$231.00 | |
|GM28 Power Supply |$33.00 | |
|GM28 Antenna |$22.00 | |
|Microcontroller Starter Kit |$85.00 | |
|Poster |$50.00 | |
|Subtotal |$429.00 | |
| | | |
|Labor (at $10.30/hr) | | |
|Adam Mohling | |$1957.00 |
|Chau Nguyen | |$1833.40 |
|Issa Drame | |$1895.20 |
|Arturo Palau | |$762.20 |
|Subtotal | |$6447.80 |
|Total | |$6876.80 |
|Final Total Cost |
|Parts and Materials | | |
|GM28 GSM Cellular module |$0.00 | |
|GM28 Power Supply |$0.00 | |
|GM28 Antenna |$0.00 | |
|Microcontroller Starter Kit |$0.00 | |
|Prepaid Cellular Phone |$20.00 | |
|Fan |$30.00 | |
|Thermostat |$15.16 | |
|Cable |$5.95 | |
|Misc. Electronic Components |$20.22 | |
|Poster |$17.50 | |
|** Additional circuit components (Table 7 below) |$40.08 | |
|Subtotal |$148.91 | |
| | | |
|Labor (at $10.30/hr) | | |
|Adam Mohling | |$2688.30 |
|Chau Nguyen | |$2410.20 |
|Issa Drame | |$2554.40 |
|Arturo Palau | |$762.20 |
|Subtotal | |$8415.10 |
|Total | |$8564.01 |
Table 7 – Detailed Circuit Financial Requirements
|Part Number |Description |Unit price |Qty |Subtotal |
|588-12FR080 |.8 ohm res |1.56 |4 |$6.24 |
|511-UA741CN |op amp |0.25 |16 |$4.00 |
|512-1N3595 |diodes |0.08 |12 |$0.96 |
|660-RC1/4TT52R104J |100k res. |0.13 |5 |$0.65 |
|588-43F-4K |4k res. |1.91 |3 |$5.73 |
|293-2K/REEL |2k res. |0.1 |3 |$0.03 |
|294-1K-RC |1k res. |0.14 |6 |$0.84 |
|140-MLNP50V.22 |220nf cap. |0.3 |5 |$1.50 |
|655-T77S1D10-05 |SPST-NO relay |1.56 |5 |$7.80 |
|655-T73S5D15-05 |SPDT relay |2.03 |3 |$6.09 |
|PIC18LF452-I/P |backup microcontroller|5.97 |1 |$5.97 |
| | | |Total |$40.08 |
2. Schedules
To date, the team has managed to stay close to the projected schedule. The only major difference between the previous and current Gantt chart is that the team’s project poster has been moved to the 2nd semester of the course. The rest of the scheduling issues will be addressed in their related sub-sections.
[pic][pic]
Figure 11 – Original Project Schedule Summary
The only difference between the original project schedule and the current project schedule is that the poster has been moved to the next semester. This is also reflected in the detailed project reporting schedule
Figure 12 – Final Project Schedule Summary
Scheduling for the team was separated into the two main section of the project, project reporting and project development. The project development followed very closely to the projected hours, however the development did not. The development took a little longer to begin due to delays from Kanda in sending the team’s microcontroller. The following Gantt charts shows the hours spent on each portion of the project.
[pic]
Figure 13 – Original Project Reporting Schedule
[pic]
Figure 14 – Design Report Project Reporting Schedule
** Notice the project poster is the only change from the previous to the current schedule.
[pic][pic]
Figure 15 – Final Project Reporting Schedule
For the final project reporting schedule, there is not much of a change to report because a majority of the reporting was completed the previous semester. The only major change to be reported is that the team did not start work on the final report as planned. Instead, work began approximately one week later than expected. The reason for this is the team was busy working on the development portion of the project.
[pic]
Figure 16 – Project Development Schedule
Since the team had not reached the development stage by the time of the design report, there was never a proposed change to the project development schedule. This being the case, there is only an original and an actual project development schedule to report.
[pic]
Figure 17 – Final Project Development Schedule
This schedules shows what the team was able to complete over the course of the two semester of enrollment in the senior design course.
3. Closure Materials
This section provides contact information for all significant parties involved in the project. Also included are a closing summary intended to give the reader a final perspective on the whole project and a list of references the team will be using during the course of the project.
1. Project Evaluation
There are many factors to take into consideration while evaluating the overall success / failure of this team project. The most logical way of evaluating the project is to follow the Gantt charts created at the beginning of the project and referenced in the previous section.
The reporting for the entire project went very well. The team showed improvement on all documents as the semester progressed. All documents were completed on time with minimal “crunch time” every required by the team members. The only exception to this was for the final report. The team was very busying working on the development stage that the documentation was pushed back and started one week later then what was planned.
The poster was originally presumed to be due during the first semester, so the team had this nearly completed before the end of the first half of the semester. This is why the Gantt chart shows work on the poster spanning over such a great deal of time. There was too much information to place onto the poster in order to completely meet all the poster criteria and the main complaint about the team’s poster was that the type was too small.
Development for the team was much more difficult than originally expected. There was not enough support on the team to complete this project with just three members. The team often caught themselves working 10 hour days during the week and sometimes more on the weekends. Most of this time was spent researching how to manipulate the components of the system. Although a great deal of knowledge was obtained during this time, some obstacles still remained uncompleted.
In order to complete the project on time, some tasks were dropped from the team’s proposed development task set. A majority of these were not required, just were thought to be convenient to the system. These tasks are as follows:
• Implement surge protection
• Battery backup implementation
• Test battery backup operation
• Test battery backup lifetime
• Functionality menu interface
Other features were met during the development of the system. These tasks are as follows:
• Test security protocols
• Test user message integrity
All of the proposed controlled devices have been simulated by the team and can be controlled by applying voltages to the correct I/O pins. The team was able to also decode the LCD display of the thermostat and manipulate the values sent to the LCD. This was very impressive because the team was not sure if this could be done. The problem with this is that it required many more I/O pins to read and decode the value of the LCD. Fortunately, the team accounted for the need for additional I/O pins and this was therefore not a problem.
Compiling code on the STK microcontroller was a success. This allowed the team to be able to read I/O pins that were connected to the controlled devices. This was also viewed as a success by the team.
Connectivity to the GM28 was established. Software was created that was able to receive messages sent by remote users and the data was parsed and made available for processing. Settings on the GM28 were also able to be set and manipulated providing for additional functionality. A major obstacle for this portion of the project was sending a message to the remote users resulted in the GM28 returning a +CME 304 error: “invalid PDU format”. This error means that the message to be sent was not of a valid PDU format, however the team was not sending messages in the PDU format (the team was using text format). Even after changing to the PDU format and changing the modem to accept PDU format messages, the problem still persisted. Upon running the software on the STK, the problem resolved itself.
Status detection for the team proved to be quite an obstacle. What seemed to be a simple task became a length task. The team was finally able to answer this problem and a current detection circuit is shown in figure 8.
Taking all of these factors into consideration, the project was seen to be almost as a success. Users were able to control devices from a remote location. The status of a device was able to be acquired. The users interacting with the system could be properly authenticated. Users were able to receive notification of the resultant outcome of their request. The only problems that arose during the project were that there was not enough time to do full system testing. All the testing had to be done along the way.
2. Commercialization
This system can be used to utilize M2M connectivity and provide a great deal of efficiency to a business environment. Primary candidates for remote monitoring include but are not limited devices such as:
• Monitoring a vending machine and reporting back when a particular product is running low. This would increase sales if a product was always available to the customer.
• Remotely monitoring the use of appliances in a building
• Creating a log of the actions within a building such as when a door was opened, light turned on/off, etc.
This product would be feasible for commercialization to a typical household due to the amount of effort that goes into interfacing the system with target controlled devices. A company could profit from and save man hours by using this system. This system could replace sending an employee to a remote site for simple monitoring of an event.
If an entity wanted to be signaled when an event took place, they could use this system. The cost of having a security guard, for example, would be much more expensive than installing this system. A message could be sent stating that a door has been opened and proper actions could then be deployed.
All printing was performed from the Coover labs and was taken from team member’s print quotas. These costs were ignored due to the fact that the team did not incur any additional financial burdens from printing in this manner.
3. Additional Work
Since this project is not an ongoing project, there will not be any work to be done after the end of this semester. If this project was to be handed on to another team, the documentation and current circuit designs would be made available to the incoming team. An informative session lasting approximately one hour would also be necessary to guarantee any special instructions were included.
4. Lessons Learned
The following is a list of the experiences gained by this group in the processes of developing this project. The experiences are classified in two groups: Project experience and new technical knowledge gained.
New Technical knowledge
• The mechanics of and LCD matrices
• The details of AC/DC signal conversion
• The SMS text message
• Serial programming
• Furthered C programming skills
• Development of code for a microcontroller
• The use of relays, and optocouplers for control applications
• FTP and shared storage resources for files and other information
Project Experience
• Professional project planning, scheduling, conducting and management.
• Personal time management required to efficiently contribute to this type of project
• Use of outside resources when the team was not able to figure out the complicated issues
• Including ‘slack time’ is very important in a project and is necessary to handle unforeseen events.
• The need for an individual to facilitate the project also exists. Someone to make sure that tasks start on time and are being completed in a reasonable amount of time.
• Time management
5. Risk and Management
The anticipated potential risks and planned management for the project are as follows:
1. Loss of team member(s)
There will be always at least two team members that are involved with designing of every subsystem. This will ensure that at least two team members who are familiar with every subsystem. So in the event of losing a team member, there will be a secondary team member who can take over the responsibilities.
2. Lack of expertise in team members
Adequate time to research the technology will be required after selecting the technology to be used in the project. Team member are also responsible to seek out help where ever it applies. Frequent meeting and project update with faculty advisor will ensure correct approaches are utilized in the completion of the project. In the even that the team is not able to perform the necessary development on their own, outside sources will be consulted.
3. Legal risk of product failure/defect
Appropriate warnings will accompany the product.
4. Electric shock
Proper electric device practices will be included in the product manual and warnings will be posted in a highly visible spot on the product.
5. Delay in receiving components
In the even that one of the system components happens to be delayed, the team will work on other portions of the product. This will ensure that the project will not fall behind schedule and create slack later in the project’s life.
The anticipated risks actually encountered and the success in management of the risks will now be discussed.
1. Loss of a team member
The team found out rather early on in the project that one of the team members would only be working on the project for half of the semester. For this reason, this team member was assigned to mostly documentation and other tasks that would not necessarily be followed. This way this team member would not cause such an impact on the team after they left.
2. Lack of expertise amongst team members
For this risk, the team consulted a former employee of one of the team members that was proficient with microcontroller programming. This individual was able to help the team compile C code on the microcontroller and perform initial serial communication.
3. Delay in receiving components
The team members focused on other aspects of the project such as circuit design and testing.
The unanticipated risks encountered will now be discussed. The attempts to manage these risks and the success and/or failures of which will now be discussed.
1. Failure of a system component
The team happened to break the fan component of the system. The initial decision to use this fan was because one of the team members owned this same fan and had performed the initial design development at home. The decision was made to then use this fan, and if this fan is also damaged, the team will purchase another fan for this member. The team knows what happened to cause the fan to be damaged and can therefore prevent this from happening again.
2. Failure of the Pre-Paid cell phone sim card
The team purchased a Pre-Paid cell phone from Wal-Mart and had planned to use this sim card in the GM28 to bed used in the system. When activating the sim card, the team had to register a phone serial number as well as a serial number for the sim card. The sim card was then placed in the GM28 and the GM28 returned a “No GSM service available” or “No sim card detected”. Upon placing another sim card in the GM28 from a team member’s phone, the GM28 performed as projected. The team realized that the registered sim card only worked in the matching cell phone. Both sim cards used the same GSM network and should have at least been classified as “roaming” if they did not use the same carrier. The team decided to continue using the team member’s sim card.
3. Failure of the C code to perform message sending
By writing to the serial port in a UNIX environment, the GM28 would cause a “+CME 304 error: ‘invalid PDU format’”. The team then decided to send sms messages the GM28 would have to toggle between text and PDU format in order to send messages. This however, also produced the same response.
The resultant changes made to the risk management because of the encountered unanticipated risks are that these risks were added to the risk section of the documentation.
6. Project Team Information
Client Information
Senior Design, Iowa State University
Dr. John W. Lamont Prof. Ralph Patterson III
324 Town Engineering 326 Town Engineering
Ames, IA 50012 Ames, IA 50012
(515) 294-3600 (515) 294-2428
jwlamont@ee.iastate.edu repiii@iastate.edu
ece.iastate.edu
Faculty Advisor Information
Prof. Ahmed E. Kamal, Professor
Iowa State University
Ames, IA 50011-3060
(515) 294-3580
FAX 515 294-8432
kamal@iastate.edu
public.iastate.edu/~kamal
Department of Electrical and Computer Engineering
3222 Coover Hall
Ames, Iowa 50011
Student Team Information
Arturo Palau – EE
80 Linden Devitt
Ames, IA 50011
(515)708-3812(Cell)
apalau@iastate.edu
Issa Drame – EE
4335 Frederickson Court
Ames, IA 50010
(515)572-7820
issad@iastate.edu
7. Closing Summary
Although this cell phone based remote home control system is applied to a limited number of devices in this project, its basic building blocks would remain the same, should one implement the remote control of any other electronically controllable device. Programming and hardware additions would make such an undertaking possible. Moreover, given the successful bid to integrate functionalities into cell phones, cellular companies may find the idea of the remote home control system to be an attractive option, therefore such a system has a potential for success in commercial applications.
8. Reference:
Senior Design Course Notes – Iowa State University
Available at
9. Appendix
Appendix A
GM28 GSM Module Images
[pic]
Appendix B
STK300 Microcontroller Developers Kit Images
[pic]
Appendix C
List of approved commands for the
Cell Phone Based Remote Home Control System
LIGHT:
LIGHT ON
LIGHT OFF
LIGHT STATUS
FAN:
FAN STATUS
FAN OFF
FAN LO
FAN MED
FAN HI
THERMOSTAT:
THERMO STATUS
ALERT THERMO ABOVE XX
ALERT THERMO BELOW XX
INCREASE THERMO TEMP BY XX
DECREASE THERMO TEMP BY XX
SET THERMO TEMP TO XX
SYSTEM COMMANDS
CHANGE PASS
SYSTEM SHUTDOWN
-----------------------
for(i=0; i ................
................
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