RE: Controlling AC fan using pwm library

Sigurd — Tue, 20 Nov 2018 10:21:31 GMT
Hi,
So if pin 30 is low, you should have a PWM singal on pin 31? And when pin 30 is high, the PWM signal on pin 31 should stop?
As a fast prototype, maybe you could try something like this?
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#include <stdbool.h>
#include "nrf.h"
#include "nrf_drv_gpiote.h"
#include "app_error.h"
#include "boards.h"
#include "bsp.h"
//#include "nrf_delay.h"
#include "app_pwm.h"


#define PIN_IN 30

#define DATA 31

APP_PWM_INSTANCE(PWM1,1);                 // Create the instance "PWM1" using TIMER1.

static volatile bool ready_flag;          // A flag indicating PWM status.

void pwm_ready_callback(uint32_t pwm_id)    // PWM callback function
{
    ready_flag = true;
}


void in_pin_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action)
{

  if (action == NRF_GPIOTE_POLARITY_TOGGLE)
  {
      if (!nrf_drv_gpiote_in_is_set(pin)) // From High to low.
      {
         //Start PWM, set duty cycle to desired value
         /* Set the duty cycle - keep trying until PWM is ready... */
         while (app_pwm_channel_duty_set(&PWM1,0,50) == NRF_ERROR_BUSY);
      } 
      else  // From Low to high.
      {
         //Stop PWM, set duty cycle to 0
         while (app_pwm_channel_duty_set(&PWM1,0,0) == NRF_ERROR_BUSY); 
      }
  }  
}
/**
 * @brief Function for configuring: PIN_IN pin for input,
 * and configures GPIOTE to give an interrupt on pin change.
 */
static void gpio_init(void)
{
    ret_code_t err_code;

    err_code = nrf_drv_gpiote_init();
    APP_ERROR_CHECK(err_code);

    nrf_drv_gpiote_in_config_t in_config = GPIOTE_CONFIG_IN_SENSE_TOGGLE(true);
    in_config.pull = NRF_GPIO_PIN_PULLUP;

    err_code = nrf_drv_gpiote_in_init(PIN_IN, &in_config, in_pin_handler);
    APP_ERROR_CHECK(err_code);

    nrf_drv_gpiote_in_event_enable(PIN_IN, true);
}

static void pwm_init()
{
    uint32_t err_code;
    app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(20000L,DATA);
    /* Initialize and enable PWM. */
    err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
    APP_ERROR_CHECK(err_code);
    app_pwm_enable(&PWM1);   
}

/**
 * @brief Function for application main entry.
 */
int main(void)
{
    gpio_init();
    pwm_init();

    while (true)
    {
        __WFE();
    }
}


/** @} */