PROJECT OVERVIEW GSM SECTION BLUE TOOTH SECTION SOFTWARE DEVELOPMENT CIRCUIT DEVELOPMENT LESSONS LEARNED AND CHALLENGES FACED

We want to develop a far end remote control system using short message service (sms) and Bluetooth. Here first the cellular phone transmits a short message control command to the controlling device. The controlling device builds a bluetooth connection with the controlled device after it has been found. The controlled device controls an output.

We had to change the microcontroller from ATtiny12 to atmega32 since ATtiny12 was not available. We had to change the code respectively. We chose atmega32 because: 1. As bluetooth section had to be added we needed more Flash memory. ATtiny had 4kb of flash where as atmega 32 has 32kb of flash memory. 2. We did not had to make much changes in code as both are atmel products and can be coded in avr. 3. It is readily available.

We tried to use phone instead of GSM modem using rs232 to USB converter. But the level of signal reduced drastically due to many conversions. So we decided upon using GSM modem which costs around Rs We have been given grant from the college. The processing took around 15 days to order it through college. We will get the modem in next 5 days. We can complete the circuit then as rest of the parts are ready.

BLUETOOTH MODULE SOFTWARE DEVELOPMENT HARDWARE DEVELOPMENT

We are using Bluetooth modem- bluesmirf gold from Sparkfun ltd. Why we chose bluesmirf gold? - It fulfils the requirements of project. - It has got built in antenna. - It has auto discovery feature. - It is the only available bluetooth module in India in our affordable range.

Specifications for the same are: FCC Approved Class 1 Bluetooth Radio Modem Extremely small radio x0.6x1.9" Very robust link both in integrity and transmission distance (100m) - no more buffer overruns! Low power consumption : 25mA avg Hardy frequency hopping scheme - operates in harsh RF environments like WiFi, g, and Zigbee Frequency: 2.4~2.524 GHz Operating Voltage: 3.3V-6V Serial communications: bps Operating Temperature: -40 ~ +70C Built-in antenna

Microcontroller at89c2091 receives the data from mobile through bluetooth. The devices to be controlled are connected at its port1 at pins P1.0 to P1.6 The python code in mobile sends the data to bluetooth. The at89c2051 Decodes it. It gives a high at the port pin on which device has to be turned on and Gives a low on the pin if device has to be turned off.

Import the inbuilt modules. Create the user interface. Assign code for each pin of the microcontroller. Assign hot key to the devices.

We did not need large flash memory so it provides a cost effective solution. It has a flash of 2kb. It is compatible with MCS-51 instruction set so it becomes easier to write the code. It supports two software selectable power saving modes.

It consists of high voltage, high current darlington arrays. Featuring continuous load current ratings to 500 mA, darlington arrays are ideally suited for interfacing between low-level logic circuitry and multiple peripheral power loads. It amplifies the signal it get from at89c2051. We are not using it currently because we are driving LED which cannot take high current.

Coding in MCS-51. Coding in python. Coding in J2ME(beginning ) Handling static charge devices. Serial communication through bluetooth Using Tera term pro Using python emulator Using Rococo bluetooth simulator PCB schematic designing in expressPCB Circuit design using microcontroller

We did not find attiny12 suitable so had to substitute it with atmega32. The circuit did not work with rs232 to usb converter so we had to switch to gsm modem. Converting bluetooth module into suitable form. Configuring bluetooth module. Financing the project.

Completing GSM circuit. Integrating bluetooth and GSM circuit. Adding features like security and user friendly functions etc…

Dhananjay V. Gadre,”Programming and customizing AVR microcontrollers”. TaTa McGraw Hill, EDITION II Fred Eady.”Networking and internetworking with microcontrollers”.,oxford publications. “ Bluetooth technology and its applications with Java and J2ME”, C.S.R. Prabhu and A. Pratap Reddi, Prentice hall India,2004 “Mobile computing”, by Raj Kamal,oxford publications. “J2ME in a nutshell”, Kim Topley, O’reilly publications “Programming mobile phones and its applications to wireless networking”, Frank H.P. Fitzek and Frank Reichert, Springer publications, 2007 ATMEGA32 datasheet from Atmel. AVR instruction set from Atmel. AVR studio tutorial from Atmel

Programming with python for s-60 platform, Nokia forum. Datasheet for at89c2051 by Atmel. Datasheet fro ULN2803. Datasheet for bluesmurf gold by Sparkfun. circuit.GIF http//