PWM with a piezo buzzer,How can I change the PWM frequency?

[Mike]

I use the nrf51822qfaa,s110 v8.00,SDK V10.0. I use PWM module with a piezo buzzer. Now I need change the buzzer frequency, How can I change the PWM frequency?

for example:

/* 2-channel PWM, 200Hz, output on DK LED pins. */
app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_2CH(5000L, BSP_LED_0, BSP_LED_1);

[Ole Bauck]

You cannot change the PWM frequency without un-initializing and then initialize the PWM instance again.

[Mike]

Is this OK?

 /*
 init, Once executed
 */

 void pwm_init(void)  
 {
    /* 1-channel PWM, 200Hz, output on DK LED pins. */
    app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(5000L, BSP_LED_0);
    
    /* Switch the polarity of the second channel. */
    pwm1_cfg.pin_polarity[1] = APP_PWM_POLARITY_ACTIVE_HIGH;
    
    /* Initialize and enable PWM. */
    err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
    APP_ERROR_CHECK(err_code);
    app_pwm_enable(&PWM1);
  }
  

  
 /*
 pwm_change_frequency,Can be executed multiple times
 */
   void pwm_change_frequency(uint16_t freq)  
 {
 
  app_pwm_disenable(&PWM1);
  app_pwm_uninit(&PWM1);  
     /* 1-channel PWM, 200Hz, output on DK LED pins. */
    app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(freq, BSP_LED_0);
    
    /* Switch the polarity of the second channel. */
    pwm1_cfg.pin_polarity[1] = APP_PWM_POLARITY_ACTIVE_HIGH;
    
    /* Initialize and enable PWM. */
    err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
    APP_ERROR_CHECK(err_code);
    app_pwm_enable(&PWM1);
    
    }