= First Prototype = Ok, it is winter time and it is cold outside, and I started to build the first prototype. The problem is, that I am working only in my free time, so I have not much time to spend on this project. Therefor it just continues slowly. Ok, nevermind, let's rock. First of all, take care of the size for the self-made PCBs where I will put my prototype on: [[Image(http://www.tevs.eu/media/images/projects/openbm/DSCI2740.JPG, 400px)]] Next thought was, how to connect that board. I decided to do it cable, by cable, in this way: [[Image(http://www.tevs.eu/media/images/projects/openbm/DSCI2742.JPG, 400px)]] Which ended up in a disaster of cables. The connections were unstable and everytime I moved the small PCBs the connection even breaked down. So, don't even try this. I had to make this experience, to make it next time better: [[Image(http://www.tevs.eu/media/images/projects/openbm/DSCI2805.JPG, 400px)]] [[Image(http://www.tevs.eu/media/images/projects/openbm/DSCI2948.JPG, 400px)]] The board is driven by an [http://www.atmel.com/dyn/resources/prod_documents/doc2503.pdf ATmega32] uC with 32K flash memory by 14MhZ. As connection to BMW's bus-system (i.e. I-Bus) I am using TH3122 chip from Melexis. After trying several things, I just didn't came up to a good result, because this amount of cables was just unhandable. The comparison of the PDIP and TQFP package of the same uC shows the differences, so I had to get everything smaller, otherwise the project will not survive. In the right part of the image, you can see the differences in sizes between TQFP and PDIP package of the ATmega32 microcontroller: [[Image(http://www.tevs.eu/media/images/projects/openbm/DSCI2949.JPG, 400px)]]