Cell Phone Based Remote Home Control System

May-06-13

Project Plan

Client:

ECpE Department

Advisor:

Prof. Ahmed Kamal

Team:

Arturo Palau (EE)

Chau Nguyen (EE)

Issa Drame (EE)

Adam Mohling (CprE)

REPORT DISCLAIMER NOTICE

DISCLAIMER: This document was developed as a part of the requirements of an electrical and computer engineering course at IowaStateUniversity, 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 IowaStateUniversity 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.

23 – September – 2005

Table of Contents

i.List of Tables

ii.List of Figures

iii.List of Definitions

1.Introductory Material

1.1.Abstract

1.2.Acknowledgements

1.3.Problem Statement

1.4.Operating Environment

1.5.Intended Users and Uses

1.6.Assumptions

1.7.Limitations

1.8.Expected End Product

2.Proposed approach

2.1.Functional Requirements

2.2.Constraints Considerations

2.3.Technology Considerations

2.4.Technical Approach

2.5.Testing Requirements

2.6.Security Considerations

2.7.Safety Considerations

2.8.Intellectual Property

2.9.Commercialization

2.10.Risks and Management

2.11.Milestones and Evaluation

2.12.Project Tracking Procedures

3.Statement of work

3.1.Task 1 – Problem Definition

3.2.Task 2 – Technology Considerations

3.3.Task 3 – Cell Phone Receiver Station (End-Product Design)

3.4.Task 4 – End-Product Prototype Implementation

3.5.Task 5 – End-Product Testing

3.6.Task 6 – End-Product Documentation

3.7.Task 7 – End-Product Demonstration

3.8.Task 8 – Project Reporting

4.RESOURCES

4.1.Personnel

4.2.Financial Requirements

5.Schedule

5.1.General Summary of Project Schedule

5.2.Project Reporting Schedule

5.3.Project Development Schedule

Table of Contents Continued

6.Closure material

6.1.Client Information

6.2.Faculty Advisor Information

6.3.Student Team Information

7.References

List of Tables

Table 4.1 Personnel Hours ..…………………………………………………28

Table 4.2 Financial Layout……………………………………………………28

List of Figures

Figure 2.1 System Operation Flow Diagram………………………………….… 7

Figure 5.1 General Summary of Project Schedule………………………….....29

Figure 5.2 Project Reporting Schedule…………………………………...... 30

Figure 5.3 Project Development Schedule…………………………………...... 31

List of Definitions

GSM (Global System for Mobile communications); is a cellular communication standard.

DTMF (dual-tone multi-frequency): is used for telephone signaling over the line in the voice frequency band to the call switching center.

GPRS (General Packet Radio Service): is a mobile data service offered to GSM mobile users.

SMS (short message service): is a service available on most digital mobile phones that permit the sending of short messages (also known as text messaging service).

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.

1.Introductory Material

This section will introduce the project. It also will state the basic problem, and the basic characteristics of the project, such as operating environment, users, etc.

1.1.Abstract

The objective of this project is to enable users to remotely control their home appliances and systems using a cell phone-based interface. To access the control unit, the user should send an authentication code along with the required/desired function/action to his/her home control system via GSM. Upon being properly authenticated, the cell phone-based interface at home (control unit) would relay the commands to a microcontroller that would perform the required function/action, and return a function completion code that would be sent to the source of the original command (user’s cell phone).

1.2.Acknowledgements

Special thanks are extended to Professor Ahmed Kamal for his support and mentorship towards the development and success of this project.

1.3.Problem Statement

The objective of this project is to develop a device that allows for a user to remotely control and monitor multiple home appliances using a cellular phone. This system will be a powerful and flexible tool that will offer this service at any time, and from anywhere with the constraints of the technologies being applied. Possible target appliances include (but are not limited to) climate control systems, security systems, and lights; anything with an electrical interface.

The proposed approach for designing this system is to implement a microcontroller-based control module that receives its instructions and commands from a cellular phone over the GSM network. The microcontroller then will carry out the issued commands and then communicate 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.

1.4.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.

1.5.Intended Users and 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.

1.6.Assumptions

The following is a list of assumptions for the project;

1.)The user and control unit will establish communication via GSM.

2.)The cell phone and service provider chosen will support text messaging service.

3.)The user is familiar with the text messaging program on their cell phone.

4.)All service charges from service provider apply.

5.)The controlled appliances can will have to have an electrical interface inorder to be controlled by microcontroller.

1.7.Limitations

The following is a list of limitations for the project.

1.)The receiver must reside in a location where a signal with sufficient strength can be received from a cellular phone network.

2.)The only person who can communicate with the control module is the person who will be successfully authenticated.

3.)Only devices with electrical controlling input ports will be possible targets for control.

4.)The controlled devices will have I/O ports that will make communication with the receiver possible.

5.)The receiver must have a power source (120V) attached at all times.

6.)Operation of the controlling unit is only possible through a cell phone with SMS messaging capabilities.

7.)The controlling unit must be able to receive and decode SMS messages.

1.8.Expected End Product

The following is a list of expected end products and other deliverables.

1.)A single M2M controller module that can perform the following:

a.Receive instructions and commands from a messaging device on a communication network

b.Monitor a device status from an electronic interface

c.Control target devices through an electrical interface

2.)A list of approved message input commands that the device is capable of executing

3.)Develop a user manual for reference by the end user.

4.)Project plan is required to defined and outline project approaches and deliverables.

5.)Project poster is required to showcase the project to the students and faculties members.

6.)Design document is required to outline our technical requirements and system’s functionalities.

7.)Final report is required for documentations on the overall project, including; end results, success, failures, etc

2.Proposed approach

This section outlines the criteria that will be considered in the development of the control system.

2.1.Functional Requirements

The following is a list of functional requirements of the control unit/module.

1.)The control unit will have the ability to connect to the cellular network automatically.

2.)The control unit will be able to receive text messages and will be able to parse and interpret (ASCII) text messages for password identification and instructions to be sent to the microcontroller.

3.)The microcontroller within the control unit will issue its command to the electrical appliances through a simple control circuit.

4.)The control unit will control the electrical appliances and detect the status of the appliances to be relay back to the microcontroller.

5.)The microcontroller within the control unit should be able to send status messages back to the cellular phone through the cellular network.

6.)The system should provide user authentication through cell phone number identification and/or password verification contained within the (SMS) text message.

2.2.Constraints Considerations

The following is a list of constraint considerations

1.)The controlled appliances will need an electrical control interface. This simple system is only capable of controlling electrical devices.

2.)The control module will need to be shielded against electrostatic discharges. This will increase reliability of the system.

3.)Battery backup for controlling unit will be implemented in case of power disruption. This is necessary to provide the user with status messages such as “power failure - system unavailable”. With this information, the user knows that communication with the system has been established. If there was not return message sent, the user has no knowledge of whether the message was received by the controlling unit.

2.3.Technology Considerations

The considerations for this system will include a choice of networks, communication protocols, and interfaces.

1.)Cellular Networks: The widely available networks are based on GSM. This network provides a wide area of coverage and can be utilized more cost-effectively for this project.

2.)Communication protocols: The available communication protocols are DTMF, GPRS and SMS. The SMS is the most efficient because this project requires a cellular communication and limited data to be sent.

3.)I/O interfaces between microcontroller and devices: Serial or parallel I/O will be considered as options for connection between the GSM receiver and the microcontroller. Using the microcontroller, a control circuit will be implemented to control the electrical appliances.

2.4.Technical Approach

1.)Assuming that the control unit is powered and operating properly, the process of controlling a home device will proceed through the following steps:

The remote user sends text messages including authentication information and commands to the receiver.

GSM receiver receives messages sent from user cell phone.

GSM receiver parses the string for the authentication information, and the commands.

GSM receiver sends the commands to the microcontroller.

Microcontroller issues commands to the appliances.

Microcontroller checks for completion status and sent it back to the GSM receiver.

GSM receiver informs the remote user of the outcome of their request by sending a completion status message back to remote user in the form of another SMS message.

Figure 2.1 System Operation Flow Diagram

2.5.Testing Requirements

The following testing requirements will be indicators that the system can successfully be implemented.

1.)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.

2.)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.

3.)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 team members 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.

4.)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 by team members for this phase:

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.

5.)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.

6.)The I/O command’s voltage will be tested to meet the levels required to actuate the individual devices. The following procedure will be performed by EE team members:

A simulated command from the microcontroller will be written to its I/O port.

The output voltage at the desired device’s control interface will be measured to verify its strength.

Success/Failure criteria:The test will be considered successful if the simulated command from the microcontroller causes the proper voltage to be observed at the desired device’s control interface.

7.)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.

8.)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.

9.)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 donot meet the manufacturers’ requirements.

10.)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.

11.)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.