Project TARAS

This week I have worked on interfacing gps/gsm module sim 908 with Arduino. The following are the complied results on the module.

What is SIM908?

SIM908 module is a complete Quad-Band GSM/GPRS module which combines GPS technology for satellite navigation. The compact design which integrated GPRS and GPS in a SMT package will significantly save both time and costs for customers to develop GPS enabled applications. Featuring an industry-standard interface and GPS function, it allows variable assets to be tracked seamlessly at any location and anytime with signal coverage.

Difference between Sim 800 and 900?

SIM800 vs SIM900 GSM modules There exist multiple versions of these modules,  SIM900 comes in the form of full version Quad band SIM900 & dual band version SIM900A, SIM900D  SIM800 comes in the form of full version Quad band SIM800 & stripped down compact size version SIM800C.  There are other SIM800 & SIM900 versions but very less information available about them, so they have not been discussed.

Since we are already very familiar with interfacing the SIM900 modem and have played around with the AT commands, the questions that come to our mind are listed below. I have tried to answer them after doing a bit web research.   “What extra does SIM800 modules give me compared to SIM900 series modules?”  SIM800 GSM modules have a inbuilt Bluetooth stack compliant with 3.0+EDR & FM radio support, and the interface is accessible using AT commands. SIM800C GSM module is comes in a very compact size of 17.615.72.3 mm dimensions compared to SIM900/SIM900 which come in 24243mm package.   “How compatible are these both modem series?”  SIM800,SIM800C modem operates from 3.4V to 4.4V supply range (Reduced operating range  !) SIM900, SIM900A modules operate from 3.2V to 4.8V supply range.  Same AT commands used for simple call/sms functionality in SIM900,SIM900A can be used with the SIM800,SIM800C modules, but SIM800 series have added AT command set for supporting extra features like bluetooth.

Difference between Sim 908 and 900?

The Sim 900 module has only GSM and not GPS, Whereas SIM 908 has both GPS and GSM capability in the same module

Why are we using SIM 908?

We are using sim 908a for communication purpose. The different applications include:

• 1. GPS coordinates: Sim 908 gets the GPS coordinates from satellite with circular error probable of < 2.5 m
• 2. SMS service: Send SMS to the sever and users kin when an accident has occurred.
• 3. Make post request: we can also make post request from the module to get accident prone areas in the driver’s locality.

How is it interfaced with Arduino?

The above is how the SIM908 is connected to Arduino. It also requires a separate GPS and GSM antenna to get suitable reception for communication with Satellite and GSM towers respectively.

Arduino Library for SIM908/SIM900:

To use the gsm module with Arduino, I have used the following site to get the open source library for SIM908
GSM Library And we have used specifically the following library to make gsm module work.
IDE v307

The Practical circuit layout:

Arduino serial monitor results: