How do I interface external IO pins when app_button is used?

[syntroniks]

I would like to support app_button, however I need to configure a pin as NOPULL and trigger on a low to high transition without debouncing.

I don't see a way this can co-exist with the app_button modile. I tried using nrf_drv_gpiote but was confused when it would not let me register new event handlers.

What is the recommended way of interfacing external interrupts with an application already using app_button?

-- Is this sufficient if I use the gpiote merge fix to use both app_gpiote and nrf_drv_gpiote?

	APP_GPIOTE_INIT(2);
	app_gpiote_user_register(&userid, (1<<16), 0, evt_hdl);
	app_gpiote_user_enable(userid);

[Susheel Nuguru]

You can configure pin with different trigger level and different pulls with app_buttons static app_button_cfg_t buttons[] = { {BSP_BUTTON_0, APP_BUTTON_ACTIVE_HIGH, NRF_GPIO_PIN_NOPULL, button0_event_handler}, {BSP_BUTTON_1, APP_BUTTON_ACTIVE_LOW, NRF_GPIO_PIN_PULL, button1_event_handler}, };

Else your solution should work well if you use the merge fix.

[syntroniks]

Thanks Aryan and thank you for helping these forums. Can you confirm that this means modifying bsp.c in the RTE folder as opposed taking a weak reference to buttons and overriding it in main.c?

Thankfully my input signal is 100ms long so it will work with the debouncing logic.

[Susheel Nuguru]

Yes, override before calling the app_button_init function. If you have energy to experiment more, then you can even reduce debounce_time for that specific pin in app_button.c->gpiote_event_handler replace

err_code = app_timer_start(m_detection_delay_timer_id, m_detection_delay, NULL);

with

  if(external_pin) err_code = app_timer_start(m_detection_delay_timer_id, 5, NULL);
  else err_code = app_timer_start(m_detection_delay_timer_id, m_detection_delay, NULL);

Then you interrupt needs to stay active just for 5 ticks ...