My mate kindly donated his old broken TomTom Go 300 from which I was hoping to steal the GPS chip and antenna for use in my Arduino projects. I opened it up and found the GPS unit, it was labeled Cirocomm G100/300 580 but I couldn’t find much info about this on the net, there were several posts of people with them asking about the pin outs and one site where someone had apparently got it to work but unfortunately hadn’t detailed the pin outs. So, I had to resort to trial and error at the risk of blowing it up… It seems luck was on my side and I soon got it working, I will detail the pins I used as others seem to be after the info, I can’t grantee they are the “correct” pins, but they work for me…

I soldered to the small gold TP circles that were dotted over the board, rather than the ribbon cable connector its self. I’m guessing these are test points connect directly to the ribbon connector and other interesting places. There is a large group of them on the board on the opposite side to the ribbon connector. These are the connection I used:

And thats it, if all goes well, on the TX line you should be receiving this kind of data:

Thats NMEA data and some of those lines will constantly repeat every second or so with updated geo coords and other interesting info.

The $GPGGA line is the interesting line containing 5043.9983,N,00144.8843,W which = 50° 43.9983′ N and 1° 44.8843′ W. If you are looking to plot this on google maps dont be fooled by the fact that its in degrees and decimal minutes and that google maps uses decimal degrees so some conversion is required.

Hope this helps and let me know what cool devices you make from this unit

After my semi successful prototype of my remote control car speedometer project using a reed switch, I’m back with version 2, this time using a hall effect sensor.

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I love my Arduino development board and have done some interesting experiments with it, and now I am at the stage of wanting to make some of my circuits a bit more independent and permanent, mainly so I can continue to use development board for tinkering with while leaving my other projects in a working state. The mind, body and soul of the Arduino is the ATmega168 chip, which contains all the memory, processor, analogue to digital converters and pretty much everything else. As these chips can be picked up for only a couple of pounds I thought I would have a go at making a stand alone unit to log data to an SD card…

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I’ve recently acquired a laser pen, and of course, instantly dismantled it! I bypassed the push button and soldered on a couple of wines replacing the batteries, allowing it to be powered and controlled by the Arduino.

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As mentioned in an earlier post, I suggested the motor driver IC would be preferable over four transistors and lots of wire due to it’s small and neat package! However I have just realised something that may sway me in the other direction…

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My motor driver IC (L293D) arrived the other day, and before I put it to real use I thought I would just have a quick go at driving two motors at once…

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The next thing I wanted to try doing with my Aruino was driving some motors. I have got loads of old CD/DVD drives that I don’t use any more and thought this would be an ideal source of motors.

The motor on its own worked reasonably well connected straight between an output pin and ground, however it wasn’t particularly powerful as the output pin can only source a limited current, and I could also only turn it in one direction, without physically swapping the cables over. After a bit of research and discovered what was required to control the DC motor in both directions, and this is called a h-bridge.

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For my next project, and this is one I have been wanting to do for while, I will be makeing a speedometer for my remote control car.

“What good is that?” I hear you say, “how are you going to read the speed when it’s going past you at 30 miles per hour!?”

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