Serial PWM motor controller

[Daniel_LaFleur]

Originally Posted by smartkid

Also, what is a 4MHz Ceramic Resonator? I've looked one up, a little $1 part that I've seen before but what does it do?

A ceramic resonator is a low cost ocillator, usually used as a clock in a curcuit where the frequency of that clock does not have to be super accurate.

Originally Posted by smartkid

On the subject of the battery. I've done my homework on car batteries. I knew that the batteries weren't designed to be completely discharged and I will take care to ensure that the battery we use won't get that low. But I didn't know how long it would last, please trust me 8 hours is PLENTY

Car batteries usually have 40 Amp hours.
20% of that is 8 Amp hours.
The battery would only last 8 hours if only 1 Amp is being drawn. The CIM motors will draw far more than that (upwards of 132 Amps at stall for each motor ). At that current (not advised) you would get under 4 minutes before you would surpass the 20% draw on the battery. Now you shouldn't be drawing that much current, but calculating and budgeting the amount of current you draw and calculating how long your battery will last will tell you what type of battery (car/marine) you'll need.

[smartkid]

The battery is something for later. I don't have the money for it and the charging equipment right now. Honestly, I'm broke. It'll be a while before I can get any of this off the ground but time is something I have a lot of.

My dad seems to think that a car battery is massive overkill and too heavy. It's become a bit of a joke now.

The more pressing matter is the motor controller circuit I hope to build...

I've located this PIC and priced it (around $5, not bad) but won't I need to program the PIC itself before it does anything?

Another small question, the diagram shows one pin from the microchip connecting to each PWM output, well it's my understanding that PWN cables have three wires (black, white and red). If the microchip only outputs to one wire then I'm guessing that it's the white one and that black and red are battery and ground?