CCS/TM4C123GH6PM: How to switch ui8Adjust value (say 60 and 110) repeatatively

Hi,

  Which TI example are you referring to? Can you clarify?

  Are you trying to adjust the duty cycle or the period?

  If you want to configure duty cycle you will use PWMPulseWidthSet(). If you want to configure the period you will use PWMGenPeriodSet().

  The below would be an example to configure the PWM module. You would want to use PWM_GEN_MODE_GEN_SYNC_LOCAL so that if you want to change the duty cycle or the period repeatedly, the change will take effect at the end of the PWM cycle.

    //
    // Configure the PWM0 to count up/down with synchronization.
    //
    PWMGenConfigure(PWM0_BASE, PWM_GEN_0, PWM_GEN_MODE_UP_DOWN |
                    PWM_GEN_MODE_GEN_SYNC_LOCAL);

    //
    // Set the PWM period to 250Hz.  To calculate the appropriate parameter
    // use the following equation: N = (1 / f) * SysClk.  Where N is the
    // function parameter, f is the desired frequency, and SysClk is the
    // system clock frequency.
    // In this case you get: (1 / 250Hz) * 16MHz = 64000 cycles.  Note that
    // the maximum period you can set is 2^16.
    // TODO: modify this calculation to use the clock frequency that you are
    // using.
    //
    PWMGenPeriodSet(PWM0_BASE, PWM_GEN_0, 64000);

    //
    // Set PWM0 to a duty cycle of 25%.  You set the duty cycle as a function
    // of the period.  Since the period was set above, you can use the
    // PWMGenPeriodGet() function.  For this example the PWM will be high for
    // 25% of the time or 16000 clock ticks (64000 / 4).
    //
    PWMPulseWidthSet(PWM0_BASE, PWM_OUT_0,
                     PWMGenPeriodGet(PWM0_BASE, PWM_GEN_0) / 4);

    //
    // Enable the PWM0 Bit0 (PD0) output signal.
    //
    PWMOutputState(PWM0_BASE, PWM_OUT_0_BIT, true);

    //
    // Enable the PWM generator block.
    //
    PWMGenEnable(PWM0_BASE, PWM_GEN_0);

HI,

  Where did you get this example? I don't think this is a TivaWare example. In any case, if you want to change the duty cycle in a 2-second interval then it is best that you add a timer function into your application. The timer will be configured to timeout every 2 seconds. In the timeout ISR, you can change the duty accordingly (e.g. 110 or 60).