This is the board working as a servo controller, with three servo motor ports defined and functioning (pins 23,24,25 on the atmega168 chip), as well as a controllable status led (pin 26). The smaller chip in the top left of the photo is the MAX232, which helps out with the RS232 (com port) communication with the computer. The green LED in the rightmost corner is just showing there is power to the breadboard, but the red LED is the one attached to pin 26 - it is toggleable by the chip. The blue box is the servo motor itself - I only have one at this point, though I've tested it on all the pins. I need two more, so I can see if actually running three at once works properly. It SHOULD, I am putting output to all three ports as appropriate, but the devil is in the details.

At this point, the program on the ATMega168 starts with an output 'About to go.' to the com port. I've got putty (a terminal program) up connected to that com port, so that's what I see. At that point, keys 'q' 'w' 'e' control motor 0 (all the way left, midpoint, all the way right), asd control motor 1, zxc control motor 2. o and p turn the led on and off.

What happens is that the program 'listens' for a key press as part of the delay routine. If it has one, it adjusts the PWM for that port. While the ATMega168 actually supports PWM natively, I'm not using it - it only can generate PWM on two pins and I need three (and who knows, I may need more later). So, I'm generating it manually, looping through a timed set of instructions to make my 50hz pulses.

This is, essentially, all the electronic playing I need for my Secret Project(tm). Need to take this off the breadboard, though, and onto a more permanent board, soldered and such. Fortunately, I have duplicates of each part, so I don't have to break this working solution to build the copy!

Commercial versions of this range between 50 and 150 bucks. I can build this version for 20 bucks or so. Of course, that assumes my time is free. But learning how to do this stuff is awesome.