very basic 18F4431 PWM help needed

[poormeche]

I appologize for the extremely basic questions, but I'm trying to use an 18F4431 to generate two distinct and controllable PWM signals to drive two non-identical DC motors. I had the capability to use the CCP modules on a 16F877A to monitor the encoder and drive the PWM signal for a single DC motor with PD control, but wanted to upgrade to the 18F because of its PWM capabilities (thus freeing up the other CCP module).

My problem seems to be that I can generate a waveform on a PWM output pin, but as this is my first real microprocessor experience of any kind, I can't figure out how to change the pulse width. At a fundamental level, I believe I just don't understand what the setup_power_pwm(), setup_power_pwm_pins(), and set_pwm_duty() function calls do and how they relate to each other. The CCS Compiler documentation is proving unenlightening for me.

Second appology for the long post To summarize, how do I configure two PWM pins on an 18F4431 such that I can vary the speed of my two motors? Additionally, some explanation of the behavior of the above mentioned functions would be helpful.

[PCM programmer]

[poormeche]

Thank you for the tip. That block of sample code is just the sort of thing I've been looking for. Hopefully the process will be demystified soon.

[poormeche]

Thanks again for the help, I've gotten the PWM outputs working

However, this has led to a follow up question. Is it possible to use a CCP compare interrupt on a timer besides timer1? I would like to be able to hook my second motor encoder into timer2 (or timer5 or what have you) and use an interrupt to stop the motor after a prescribed number of encoder ticks (motor revolutions). However looking at the description of the CCP compare interrupt, it looks like it will only ever compare the value of the CCP to timer1.

I know I could probably swing the second motor's control with polling, but would prefer to use an interrupt if possible.

Thanks for any and all help!