Triggering 5 TTL clocks simultaneously

[TurboLS]

I was thinking of doing the reset on one of those HWPM things because the reset is the only constant clock. Then I could just do a conditional statement to make sure that the reset and the horizontal clocks are in synch. The good thing about that, like you said, it would run in the background and so I could run all the other clocks just as I had them. What do you think??

[mister_e]

Then I could just do a conditional statement to make sure that the reset and the horizontal clocks are in synch

mmm, IMO you can't check with internal to synchronize them. I figure you'll have to use an extra i/o to read from the PWM output. Once you get the highlevel or interrupt, you do your Horizontal stuff. A microsecond or less of
delay between to rising edge of Reset and your Horizontal... but at 3.6KHZ i can't figure it will be a big problem.

[TurboLS]

So you're saying something like:

IF PWM output is high, start the horizontal clocks

Yeah, using another I/O pin is not a problem, cuz at this point i think i am using 2 pins of portA

How would I go about getting the HPWM to oscillate at 3.6kHz with a 25% duty cycle? I will look at the manual again later today or tomorrow probably and see if i can figure it out.

thanks again, you are a huge help.

[mister_e]

it's a bit more than if pin is high... IF the according pin is at the rising edge of the signal... this ensure the right timing. Use interrupt source INT0, INT1 or else you can have on the rising edge... will be really easy now. The only thing you have to care about is the timing and latency in the other routines to get interrupt as quick as possible.

For the HPWM frequency and duty cycle, try

HPWM 1,64,3600 ' supposed to send HPWM 3.6KHZ at 25% duty

i don't know how accurate it will be. In my purpose i always set all the register myself. In your datasheet they tell you how to calculate everything.

[TurboLS]

What pin would that HPWM be coming off of??

[mister_e]

HPWM channel = CCP1 of your 18F4520 = PIN RC2 PIN 17

[TurboLS]

So I guess I could have it running in the background, then when I want to start the horizontal clocks, I could do an ON INTERRUPT command to make sure it is on the rising edge of the Reset HWPM clock.