trying to use the HPWM command

[Darrel Taylor]

Hi Rhatidbwoy,

PBP assumes that the CCP1 port is on PORTC.2, but on the 648A it's on PORTB.3

You can correct for this with ...
DEFINE CCP1_REG PORTB
DEFINE CCP1_BIT 3

However, since you had already set PORTB to all output's, that will not solve the problem.

You didn't mention what Oscillator freq you are using, but if it's more than 10mhz, you won't be able to get that low of frequency out of the CCP. For instance, at 20mhz, 1221hz is the minimum.
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[Rhatidbwoy]

I am using the internal osc. That is 4MHz. The funny thing to the whole is that I thought since I have to put 16f648a in MCStudio that would have changed this little delema that I have with the port, but I guess wrong.

I will have to try that and see if it works. It should because I have seen this setup before.

For the code below, what is the meaning to all of this. I do not get the PR2 = 49 making this 40k for the PWM period. What is the calculation and also this must be based to xtal size.

'register setup (this is for a 16F684, so it may need to be modified slightly for your chip)

PR2 = 49 'PWM Period 40K=49
CCPR1L = 10 'PWM Duty Cycle
T2CON = 4 'Timer2 = ON; Prescale = 1:1
CCP1CON = 0 'PWM module off