Helps on PWM output from K64F

linye — Thu, 16 Jun 2016 14:58:26 GMT

Hi All,

I am new to K64F. Recently, I am trying to use K64F to output a PWM signal from an GPIO ( PTB 18) with KDS 3.2 and KSDK 2.0.

So far, I have no idea on how to FTM with KSDK 2.0 to generate PWM signal. I saw lots of demo applications from KSDS 2.0, those demo applications helps a lot. But I can not find any example or demo on how to use FTM to generate PWM output.

Is there any application note available on how to use FTM with KSDK 2.0 ?

Or any demo code? It really helps a lot!

Thank you so much for helping me,

Re: Helps on PWM output from K64F

isaacavila — Mon, 20 Jun 2016 18:53:29 GMT

Hello,

If you download the SDK 2.0 package for MK64FN1M0xxx12, you can find an example for PWM implementation that is available for TWR-K64F120M board, this example is located at: <SDK_2.0_MK64FN1M0xxx12>\boards\twrk64f120m\driver_examples\ftm\pwm_twochannel.

Basically, FTM implementation is configured as follows:

void delay(void)
{
    volatile uint32_t i = 0U;
    for (i = 0U; i < 800000U; ++i)
    {
        __asm("NOP"); /* delay */
    }
}
/*!
 * @brief Main function
 */
int main(void)
{
    bool brightnessUp = true; /* Indicate LEDs are brighter or dimmer */
    ftm_config_t ftmInfo;
    uint8_t updatedDutycycle = 0U;
    ftm_chnl_pwm_signal_param_t ftmParam[2];
    /* Configure ftm params with frequency 24kHZ */
    ftmParam[0].chnlNumber = (ftm_chnl_t)BOARD_FIRST_FTM_CHANNEL;
    ftmParam[0].level = kFTM_LowTrue;
    ftmParam[0].dutyCyclePercent = 0U;
    ftmParam[0].firstEdgeDelayPercent = 0U;
    ftmParam[1].chnlNumber = (ftm_chnl_t)BOARD_SECOND_FTM_CHANNEL;
    ftmParam[1].level = kFTM_LowTrue;
    ftmParam[1].dutyCyclePercent = 0U;
    ftmParam[1].firstEdgeDelayPercent = 0U;
    /* Board pin, clock, debug console init */
    BOARD_InitPins();
    BOARD_BootClockRUN();
    BOARD_InitDebugConsole();
    /* Print a note to terminal */
    PRINTF("\r\nFTM example to output PWM on 2 channels\r\n");
    PRINTF("\r\nYou will see a change in LED brightness if an LED is connected to the FTM pin");
    PRINTF("\r\nIf no LED is connected to the FTM pin, then probe the signal using an oscilloscope");
    /*
     * ftmInfo.prescale = kFTM_Prescale_Divide_1;
     * ftmInfo.bdmMode = kFTM_BdmMode_0;
     * ftmInfo.pwmSyncMode = kFTM_SoftwareTrigger;
     * ftmInfo.reloadPoints = 0;
     * ftmInfo.faultMode = kFTM_Fault_Disable;
     * ftmInfo.faultFilterValue = 0;
     * ftmInfo.deadTimePrescale = kFTM_Deadtime_Prescale_1;
     * ftmInfo.deadTimeValue = 0;
     * ftmInfo.extTriggers = 0;
     * ftmInfo.chnlInitState = 0;
     * ftmInfo.chnlPolarity = 0;
     * ftmInfo.useGlobalTimeBase = false;
     */
    FTM_GetDefaultConfig(&ftmInfo);
    /* Initialize FTM module */
    FTM_Init(BOARD_FTM_BASEADDR, &ftmInfo);
    FTM_SetupPwm(BOARD_FTM_BASEADDR, ftmParam, 2U, kFTM_EdgeAlignedPwm, 24000U, FTM_SOURCE_CLOCK);
    FTM_StartTimer(BOARD_FTM_BASEADDR, kFTM_SystemClock);
    while (1)
    {
        /* Delay to see the change of LEDs brightness */
        delay();
        if (brightnessUp)
        {
            /* Increase duty cycle until it reach limited value */
            if (++updatedDutycycle == 100U)
            {
                brightnessUp = false;
            }
        }
        else
        {
            /* Decrease duty cycle until it reach limited value */
            if (--updatedDutycycle == 0U)
            {
                brightnessUp = true;
            }
        }
        /* Start PWM mode with updated duty cycle */
        FTM_UpdatePwmDutycycle(BOARD_FTM_BASEADDR, (ftm_chnl_t)BOARD_FIRST_FTM_CHANNEL, kFTM_EdgeAlignedPwm,
                               updatedDutycycle);
        FTM_UpdatePwmDutycycle(BOARD_FTM_BASEADDR, (ftm_chnl_t)BOARD_SECOND_FTM_CHANNEL, kFTM_EdgeAlignedPwm,
                               updatedDutycycle);
        /* Software trigger to update registers */
        FTM_SetSoftwareTrigger(BOARD_FTM_BASEADDR, true);
    }
}

I hope this can help you!

Regards,

Isaac

Re: Helps on PWM output from K64F

linye — Thu, 23 Jun 2016 10:39:54 GMT

Hi Isaac,

Thanks a lot!

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Helps on PWM output from K64F

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Re: Helps on PWM output from K64F