i.MX RT Crossover MCUsのトピックUsing rt1050 flexpwm X output

Using rt1050 flexpwm X output

peter_lombrozo — Tue, 26 Mar 2019 22:05:50 GMT

We have a hardware configuration that requires putting a PWM signal on the Flexpwm1 output X pin (GPIO_AD_B0_03). I can get the SDK PWM example to put a PWM on A or B outputs, but not the X output. I can't seem to make the PWM drivers access that pin for the pwm signal. How do I configure the FlexPWM1 module, submodule 1 to do this? Thanks.

Re: Using rt1050 flexpwm X output

kerryzhou — Wed, 27 Mar 2019 11:18:41 GMT

Hi Peter Lombrozo,

GPIO_AD_B0_03 can be used as flexpwm1.

Do you modify the pin_mux.c to configure the pin function?

If you already modify it, and it still can't work.

Please tell me the details about your modified code based on the SDK, then I will help you to check it.

Have a great day,
Kerry

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Re: Using rt1050 flexpwm X output

peter_lombrozo — Wed, 27 Mar 2019 16:28:37 GMT

Yes, I had the pin mux correct. The problem is that the PWM_X channel is not available in the SDK drivers. However, I got it to work by modifying fsl_pwm.c,h to configure PWM_X that creates a new mode that was not aligned and disabling the deadband.

fsl_pwm.c
10c10
<
---
387a388,396
> case kPWM_NonAligned:
> /* Setup the PWM period for a PWM_X non-aligned signal */
> /* Indicates the start of the PWM period */
> base->SM[subModule].INIT = 0;
> /* Indicates the center value */
> base->SM[subModule].VAL0 = (pulseCnt / 2);
> /* Indicates the end of the PWM period */
> base->SM[subModule].VAL1 = pulseCnt;
> break;
400c409
< else
---
> else if (chnlParams->pwmChannel == kPWM_PwmB)
448c457
< assert(pwmSignal < 2);
---
> assert(pwmSignal < 3);
521a531,543
> }
> break;
> case kPWM_NonAligned: // Only for PWM_X output
> pulseCnt = base->SM[subModule].VAL1;
> /* Calculate pulse width */
> pwmHighPulse = (pulseCnt * dutyCyclePercent) / 100;
> if (pwmSignal == kPWM_PwmX)
> {
> base->SM[subModule].VAL0 = pwmHighPulse;
> //base->SM[subModule].VAL1 = ;

fsl_pwm.h

230c230,231
< kPWM_EdgeAligned /*!< Unsigned edge-aligned */
---
> kPWM_EdgeAligned, /*!< Unsigned edge-aligned */
> kPWM_NonAligned /*!< Not aligned for PWM_X channel*/

Re: Using rt1050 flexpwm X output

kerryzhou — Thu, 28 Mar 2019 08:39:53 GMT

Hi Peter Lombrozo,

Thanks a lot for your updated information.

And thank you for the modified point sharing.

Now, after the modification, do you still have any problem about it?

If you still have the problems, please kindly let me know.

Have a great day,
Kerry

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