Robot update

I finally have my final pcb design ready for prototyping. I haven’t had too much free time to work on this project as I’ve been busy with work and school. The solution to the power problem I had discussed previously turned out to be caused by my lack of including decoupling capacitors at the outputs of the motor driver, which was causing a temporary loss of voltage to the micro controller. The circuit seems to run great off of 4xAA batteries without any problems. In my redesign, I’ve had to make a couple of sacrifices as I couldn’t find a good way to break out 2 of the io ports on the uC, but I figure I probably won’t need those anyway, and I’ve made up for it by including breakout ports for all of the pins on the xbee module that I will eventually be installing. So for my final design, I have the ATMega328 micro driving 2 motors through a SN754410 dual H-bridge motor controller, serial communication over RS-232 with a max232 chip handling all of the voltage levels, and an Xbee wireless module to provide wireless serial communication and about a million other features. I was able to break out 14 I/O pins, so I should be able to rapidly prototype added functionality at a later date such as sensors and other outputs. When it’s all said and done, I will have spent about $102US on this project including shipping costs, making this my most complex, expensive and fulfilling project to date.

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