Enable pwm with button click

Question

I would like to start a pwm signal on PIN 15 while BUTTON_1 or BUTTON_2 is pressed. If BUTTON_1 or BUTTON_2 is released, than there should be no signal(low) on PIN 15. 
 Setup is: 
 -SoftDevice 8.0 
 -SDK 8.1 
 -nRF51DK 
 There is a related post to this topic: devzone.nordicsemi.com/.../ 
 The problem is, if I comment out app_pwm_enable(&PWM1); in the PWMinit function then I cannot connect to the board and the buttons are also not working. 
 If I enable the pwm in the PWMinit function, then the pwm will start immediately. But the pwm should only start when BUTTON_1 or BUTTON_2 are pressed. 
 static void PWMinit(void)
{
 app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(9000L, 15);
 pwm1_cfg.pin_polarity[0] = APP_PWM_POLARITY_ACTIVE_HIGH;
 app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
 app_pwm_enable(&PWM1);
}

void pwm_stop(void)
{
 app_pwm_disable(&PWM1);
 nrf_drv_gpiote_out_task_disable(15);
 nrf_gpio_pin_clear(15);
}

void pwm_start(void)
{ 
 nrf_drv_gpiote_out_task_enable(15); 
 app_pwm_enable(&PWM1);
 while (app_pwm_channel_duty_set(&PWM1, 0, 50) == NRF_ERROR_BUSY);
}

static void button_event_handler(uint8_t pin_no, uint8_t button_action)
{
 if(button_action == APP_BUTTON_PUSH)
 {
 switch (pin_no)
 {
 case Switch_up:
 pwm_start();
 nrf_gpio_pin_set(23); 
 break;

 case Switch_down:
 pwm_start();
 nrf_gpio_pin_set(24); 
 break;
 
 default:

 break;
 }
 }
	
 else if (button_action == APP_BUTTON_RELEASE)
 {
 switch (pin_no)
 {
 case Switch_up:
 pwm_stop();
 nrf_gpio_pin_clear(23); 
 break;
 
 case Switch_down:
 pwm_stop();
 nrf_gpio_pin_clear(24); 
 break;
 
 default:
 
 break;
 }
 }
 }
 
 Motorsteurung.zip

Susheel Nuguru · Accepted Answer

The problem is, if I comment out app_pwm_enable(&PWM1); in the PWMinit function then I
cannot connect to the board and the buttons are also not working. 
 
 
 The reason for this is that after you remove app_pwm_enable from PWMinit, you still have not commented out PWMDutySet in the next line. Since you are waiting for the ready_flag inside PWNDutySet, it will never return. 
 I see that PWM_start is called not only from button_handler but also from adc_sampling_timeout_handler, auf_write_handler and ab_write_handler.
I commented it out in all except button handler and then i can turn on pwm using button1 and turn off using button2