Here’s my current progress on the robot project. First of all, I managed to get the chassis, gear box, and tank tread assembly put together correctly on my first try. This took a little bit of guess work as the directions for assembly are primarily in Japanese. I soldered on some really long leads to each motor for testing purposes(so they can reach the bread board).
I’ve breadboarded the important parts of the main control board. I’ve got the ATMega328P at the middle clocked to 16MHz, with a motor control subcircuit using the SN754410 motor controller as an H-Bridge voltage controlled current source for the motors. and a MAX232 subcircuit for serial communication with the computer
(very handy for debugging and issuing test commands to the uC)
here’s a link to the Schematic
This schematic is a working rough draft, I’m still refining it, but it gives a general idea of what I’m working with at least.
This weekend I will have some code written up so i can perform a series of tests on the circuitry, mostly what I’m concerned with is the current draw from each of the motors. This is important because I still haven’t picked a battery configuration for the final unit, but I’m thinking 4AA batteries would be the best balance of voltage, current, and size/weight. I also plan on getting more data on motor speed in the forward and reverse directions so that I can make some calculations for the software in regards to turning the unit.
All in all, I’ve made good progress over the last day or so.