how to stop pwm and set pin to clear

RE: how to stop pwm and set pin to clear

Ali — Sun, 29 May 2016 11:41:28 GMT

I face with this problem too. I'm using SDK11.0 :( after I start PWM but I can't stop it. I have try every single top steps but I didn't get any good result.

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Wed, 02 Dec 2015 19:32:41 GMT

did you try using sdk10?

RE: how to stop pwm and set pin to clear

Milk — Tue, 24 Nov 2015 08:03:58 GMT

I also met this situation by SDK9.0,still do not know how to solve this problem.

RE: how to stop pwm and set pin to clear

Mike — Wed, 09 Sep 2015 00:42:37 GMT

Using SDK 9, SD110, app_pwm driver, also app_scheduler, I am also trying to find an answer/workaround to the very same problem after trying unsuccessfully the solutions in this thread. So far I can't disable a pin left high by the PWM, using the app_pwm driver. The typical period I need is 250 us. I also tried setting duty to 0% first before disabling, but this did not help, hinting at an inversion from the toggle. I am hoping for a successful workaround before considering rewriting a PWM driver. Any news Nordic, Mahesh? Thanks!

RE: how to stop pwm and set pin to clear

Lucas — Thu, 13 Aug 2015 01:20:13 GMT

this library is a piece

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Tue, 11 Aug 2015 09:53:29 GMT

TIMER

Use of an EVENT from any TIMER module to trigger a TASK in GPIOTE or RTC using the PPI could fail under, But this workaround is enabled by default app_pwm. And it can be found here certain conditions.

RE: how to stop pwm and set pin to clear

wuvo.leo — Tue, 11 Aug 2015 09:01:26 GMT

Sorry,what's mean "PAN-73"?

RE: how to stop pwm and set pin to clear

Mahesh Venkitachalam — Sun, 09 Aug 2015 03:44:06 GMT

I suggest creating a github gist and posting a link.

RE: how to stop pwm and set pin to clear

wuvo.leo — Sun, 09 Aug 2015 03:39:24 GMT

Thanks Aryan! How to upload my code here?

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Mon, 03 Aug 2015 10:27:22 GMT

wuvo, i am not able to reproduce it, can you give me the code and the setup details on which you tried this.

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Mon, 03 Aug 2015 09:25:33 GMT

I will try it out today and see what we can do

RE: how to stop pwm and set pin to clear

wuvo.leo — Mon, 03 Aug 2015 01:32:54 GMT

my device's current is about 7uA before call pwm_start(),and call it,current is about 300uA.

RE: how to stop pwm and set pin to clear

wuvo.leo — Mon, 03 Aug 2015 01:30:49 GMT

The device's current can't decrease after call pwm_start() even if call pwm_stop().

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Sun, 02 Aug 2015 11:15:16 GMT

I did not really understand what you mean by "can't go back to start pwm before". Is this problem related to the fix we described here?

RE: how to stop pwm and set pin to clear

wuvo.leo — Sun, 02 Aug 2015 04:03:26 GMT

Thanks,Aryan! i found a new problem:after i stop pwm and uninit pwm,my device keep current about 300uA,and can't go back to start pwm before.

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Fri, 31 Jul 2015 06:01:28 GMT

Yes, still unresolved.

RE: how to stop pwm and set pin to clear

Mahesh Venkitachalam — Fri, 24 Jul 2015 15:42:58 GMT

Just want to mention that this is still a problem with 9.0.0.

RE: how to stop pwm and set pin to clear

wuvo.leo — Wed, 24 Jun 2015 08:36:01 GMT

Thanks Aryan! i solved this problem as what you said.

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Fri, 12 Jun 2015 15:52:24 GMT

That should have worked, If this does not work then it means that somewhere GPIOTE still owns the pin.

nrf_drv_gpiote_out_task_disable(SPEAKER_PIN);
nrf_gpio_cfg_output(SPEAKER_PIN);
nrf_gpio_pin_clear(SPEAKER_PIN);

RE: how to stop pwm and set pin to clear

wuvo.leo — Fri, 12 Jun 2015 13:27:28 GMT

Thanks,Aryan.i tested as what your say,but the pin is high level always.no effects.i want to controll buzzer used pwm.what's wrong?i reconfig pwm before i start(restart) pwm using code as follow:

-------------------------------------------------------------------------
uint32_t reconfig_pwm(uint32_t perior,uint8_t pin)
{
	uint32_t err_code = 0;

	err_code = app_pwm_uninit(&PWM1); 	
	APP_ERROR_CHECK(err_code);

	if( err_code == NRF_SUCCESS)
	{
	  err_code =	init_pwm(perior,pin);
		APP_ERROR_CHECK(err_code);
	}
	
	//while (app_pwm_channel_duty_set(&PWM1, 0, 50) == NRF_ERROR_BUSY);

	return err_code;

}

static uint32_t init_pwm(uint32_t perior,uint8_t pin)
 {	 
	 	uint32_t err_code = 0;

		nrf_gpio_pin_dir_set(pin, NRF_GPIO_PIN_DIR_OUTPUT);
		nrf_gpio_pin_clear(pin);
	 
    /* 2-channel PWM, 200Hz, output on DK LED pins. */
	  app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(perior, pin);
	 
	 pwm1_cfg.pin_polarity[0] = APP_PWM_POLARITY_ACTIVE_LOW;
    
    /* Initialize and enable PWM. */
    err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
    APP_ERROR_CHECK(err_code);

    return err_code;
}
------------------------------------------------------------------------------------------------
then,start it:
void pwm_start( void )
{   
   app_pwm_enable(&PWM1);
	 while (app_pwm_channel_duty_set(&PWM1, 0, 50) == NRF_ERROR_BUSY);
}
-----------------------------------------------------------------------------------------------
stop as this:
void pwm_stop( void )
{ 
	  app_pwm_disable(&PWM1);
	  nrf_drv_gpiote_out_task_disable(SPEAKER_PIN);
          nrf_gpio_pin_clear(SPEAKER_PIN);

//	  while (app_pwm_channel_duty_set(&PWM1, 0, 0) == NRF_ERROR_BUSY);
	  pos = 0;
	  time = 0;
	  k = 0;
	  freq = 0;
}

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Fri, 12 Jun 2015 12:25:27 GMT

void pwm_start( void ) {
nrf_drv_gpiote_out_task_enable(pin_number); app_pwm_enable(&PWM1); }

RE: how to stop pwm and set pin to clear

wuvo.leo — Fri, 12 Jun 2015 12:06:00 GMT

Thanks! And after stop pwm,how to restart it?

RE: how to stop pwm and set pin to clear

Susheel Nuguru — Fri, 12 Jun 2015 07:40:21 GMT

Hi wuvo, I have noticed that app_pwm library does not disable a GPIOTE config, which means that it does not free the pin from gpiote after you are done. I created a ticket for it for the team.

For your code you can do this.

before initializing pwm library, you configure the pin through gpio interface

nrf_gpio_pin_dir_set(pin_number, NRF_GPIO_PIN_DIR_OUTPUT); nrf_gpio_pin_clear(pin_number);
Then you initialize PWM using app_pwm library, do your stuff
in your pwm_stop add three lines to it

void pwm_stop( void ) { app_pwm_disable(&PWM1); nrf_drv_gpiote_out_task_disable(pin_number); nrf_gpio_cfg_output(pin_number) nrf_gpio_pin_clear(pin_number); }

Now as soon as the pin is freed by nrf_drv_gpiote_out_task_disable then gpio configuration will take into effect.

EDIT: 10.08.2015

PAN-73 workaround is enabled by default in app_pwm_init

PAN-73 workaround is disabled in app_pwm_uninit

This means there will be increase in power consumption (~50uA) if the PAN-72 workaround is enabled.

Check here