led pwm cycle

Travis Best

could someone make me up a example for doing this pwm command using interrupt instead

PWM RB.0, 220, 1000

I know theirs some examples on the one pwm section but i just cant seem to get them to work

Thanks Again
Travis

JonnyMac

Here's a simple bit of code:

' =========================================================================
  INTERRUPT 10_000
' =========================================================================

  INC pwmTimer
  IF pwmTimer = 0 THEN                          ' time for new cycle?
    acc0 = level0                               ' reset accumulator(s)
    Led0 = 0                                    ' clear PWM output(s)
  ENDIF

  INC acc0                                      ' update accumulator?
  IF acc0 = 0 THEN                              ' on rollover
    led0 = 1                                    '   activate output
  ENDIF

  RETURNINT

You need a pwm timer (for any number of outputs); when this rolls over then you start the new PWM cycle. At the start you'll transfer the level for the pin(s) to the accumulator(s) for that(those) pins; the outputs are cleared at the same time. Then you increment the accumulator(s); when there is a rollover detected then the output is activated. In use, the larger the value of "level", the sooner the output will be activated within the cycle and the brighter the LED will be.

Keep in mind that when you're using an ISR, instructions like PAUSE, SEROUT, etc. (anything timing based) is affected.

Travis Best

thanks I got it to work thanks for the help