I'm trying to rig up my own PID motion control using a DC gear motor. So far I've got a PWM controller so I can control the speed and direction of the motor. I was able to very crudely count pulses and determine position. I was not using interrupts so I doubt it is very accurate. Instead of dealing with all of this in software, I'd like to outsource the counting to an IC. I've looked at the 74HC4020, but that's parallel output. I think I'd like to use I2C or some other serial interface to poll the counter. Any reason not to? Would the speed of serial communication be a limiting issue at all? I'm not really sure what frequency I'd need to calculate and adjust the pwm to get accurate motion control.
200 rpm max * 3200 pulses/rev = 10,666 Hz.
Help me pick out a counter IC! I'll probably ditch this project soon and replace everything with Mesa boards and run LinuxCNC :grin: