Trying to get started w/ HPWM
I have a 18F67J60, and I'm trying to understand how to use the HPWM output on PORTB.3. Because I've not used HPWM before, getting started is very confusing. The datasheet refers to this pin as "ECCP2 Enhanced PWM output, channel A", but the PBP manual is talking about Channel NUMBERS.
Another concern is that I'm using DT-INTs and using TMR0 and TMR1 already. Is this a problem? Any pointers to get me started in the right direction would sure be appreciated.
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Your channel numbers are 1, 2, 3, 4, and 5 for ECCP1, ECCP2, ECCP3, CCP4 and CCP5. But none of them are on port B.3. They are a little all over the place on the chip. But ECCP1 is on PortC.2, and ECCP2 is on PortC.1Originally Posted by circuitpro
Not a problem, you will be ok here because PWM uses Timer 2 or Timer 4Another concern is that I'm using DT-INTs and using TMR0 and TMR1 already. Is this a problem? Any pointers to get me started in the right direction would sure be appreciated.
Last edited by ScaleRobotics; - 19th February 2010 at 07:12.
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I guess it's time to just get a stand-alone HPWM working on the right port/pins, and then try to integrate it with what I've got already got. Thanks.
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Oops. Missed the footnote on PortB.3!
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Hey Circuitpro,
Yes, the PBP "HPWM" command uses the hardware PWM pins on the chip. These are defined in the datasheet. To use "HPWM", you need to use one of the available HPWM pins.
You could use the PBP "PWM" command, but this does not work for continuous PWM, only a defined number of cycles.
Your only option (if you need to get continuous PWM on portb.3) is to use DT Interrupts and make your own pwm on any pin ... but this is a little more complicated. (maybe you could still use the same board if you do this ... not quite sure what your options are with your particular project.)
Edit: forgot about this option, Darrel has made it easier for everyone. http://darreltaylor.com/DT_INTS-14/SPWM.html
Last edited by ScaleRobotics; - 19th February 2010 at 19:30.
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But this uses Timer1, so I guess you are on the DIY route with interrupts, or DT Interrupts.
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