During my free time I like to take motorcycle trips and if you ever ridden a motorcycle for a long distance you will know that it can be a bit more difficult to take care of things that are normally pretty easy in the car. With that said, I probably don’t check in with my spouse as often as I should. Being that a motorcycle poses a higher chance of injury than a car, my wife tends to worry if she hasn’t heard from me in awhile. To try and alleviate some of this anxiety I looked into a number of tracking systems where my wife could easily look to see where I have been. There are numerous vendors out there using gprs and sms to update a database with your location. Many of these are quite costly for the base unit and the actual fees for access to the database. Being the embedded design engineer I am I knew there had to be a better way. So for about $100 for hardware and $15/month for sms’s you have the Twitter Tracker as seen below.
Alex over at Tinkerlog posted about using the Telit GM862, Twitter, and Google Maps for a mobile tracking solution. Although Alex did not link all these directly, I put the pieces of the puzzle together to see the solution you see here today. Overall the design is complete and very professional through the use of a proper pcb and enclosure from SFE.
Overall the idea is pretty simple. I use a pre-paid unlimited SMS plan ($15/month) through T-Mobile that allows me to send SMS messages. By registering the mobile number of the assigned SIM card I can register this account with Twitter. By doing so I am then able to send Google Map links right to my twitter account every 60 seconds when I am riding. These Google Map links are done by using the gps location from the gps device on the GM862 through the use of the GPSACP command. Parsing this string for the lat/lon locations in DDMM.MMMM format to Decimal Degrees. Results of these actions can be seen at the twitter page for my motorcycle.
A bit of breadboarding through the use of Sparkfun’s GM862 Breakout Board and MikroE’s GM862 Smart Board made the identification of the AT protocol and design of the the 12V -> 4V power supply design much easier. Full schematics of the design are below in .pdf format.
The code for this project was developed in the Proton Development Suite that we sell. Overall it was very easy to use and is pretty easy to program. In fact, the code can be edited and recompiled using the free Amicus 18 compiler since this design uses the 18F25K20 uProcessor. Source code to make this project work can be found here -> Source Code.
Let me know if you are interested in purchasing a complete setup and I’ll consider offering this design for sale!