button interruption in nRF52805

RE: button interruption in nRF52805

Edvin — Fri, 08 Jan 2021 15:48:44 GMT

It may be.

Please note that the app_button, and hence the bsp library has a software debounce, meaning that the pulse must be active (LOW in this case) continuously for 50ms by default. The time (50ms) is configurable, but if the pad already has a debounce (since it may be a "smart device", compared to a mechanical button), it may be that it outputs a pulse shorter than 50ms. If so, you may also try out the example pin_change_int, which is a very simple gpio change detector without debounce. You can give it a go if you like.

But it may also be a poor contact. Or perhaps it doesn't have the drive strength to pull down the pullup set in app_button. Try to set it to NRF_GPIO_PIN_NOPULL, as I suggested in the previous reply.

Best regards,

Edvin

RE: button interruption in nRF52805

ticture — Fri, 08 Jan 2021 13:03:49 GMT

Maybe it is the problem caused by poor contact, I will make it stable and try again these days, thank you very much.

RE: button interruption in nRF52805

Edvin — Wed, 06 Jan 2021 15:17:34 GMT

Ok, so that suggests that the pad is an active output, which doesn't only pull up or down. The pin is never floating. When the pad is pushed, the pin outputs 0, and when the pad is not pushed it outputs high.

In this case, you should not use any pullup or pulldown by using NRF_GPIO_PIN_NOPULL instead of NRF_GPIO_PIN_PULLUP.

active state should be 0 (false), like it is.

Try this, and see what happens. If you still see issues, please try to analyze the pad output using a logic analyzer. How long is the output low when you push it, or only for a few ms? Is held low while you hold it? Is it stable, or does it contain bounce?

Best regards,

Edvin

RE: button interruption in nRF52805

ticture — Wed, 06 Jan 2021 15:01:39 GMT

Thanks for you help, A B C D is like this.

	Pad pushed	Pad not pushed
GND->Output	0	3.328V
VDD->Output	-3.328V	0

Best regards.

RE: button interruption in nRF52805

Edvin — Wed, 06 Jan 2021 10:04:31 GMT

Hello,

So the app_buttons[] have 4 elements for each button.

{pin_no, active_state, pull_cfg, button_handler}

In your case, the active_state is false -> low. So the button is pushed when the pin is changed from high to low. In addition, you have a pullup set in your BUTTON_PULL. This means that if the pad is not trying to set it to either high or low, it will be pulled high.

This works well when a button push shorts the pin to ground when you push a button, and the pin is floating when the button is not pushed (because the pullup will pull it high when the button is not pushed).

Perhaps your touch pads are pulling the pins low, and have an active high? Try to measure with a voltmeter what the state of the output is when the pad is not pushed. What is the voltage difference between GND and touchpad when the pad is pushed and pad is not pushed, and what is the difference between VDD and the touchpad when the pad is pushed and not?

That is:

-	Pad pushed	Pad not pushed
GND->Output	A	B
VDD->Output	C	D

What is A, B, C, and D?

Best regards,

Edvin

RE: button interruption in nRF52805

ticture — Tue, 05 Jan 2021 11:14:17 GMT

Thanks for your help

Three button pins connect to three different touch pad, when the finger touches one of the three touch pads, it will give a high level to the button pin.

These orders can normally read the high level in button pins, when I touch the touch pad, the value these orders read will turn to 1 from 0.

nrf_gpio_pin_read(12);

nrf_gpio_pin_read(5);

nrf_gpio_pin_read(1);

BUTTON_PULL is defined like this in the pca10040.h

#define BUTTON_PULL NRF_GPIO_PIN_PULLUP

The array app_buttons is defined like this in my code

static const app_button_cfg_t app_buttons[BUTTONS_NUMBER] =

{

#ifdef BSP_BUTTON_0

{BSP_BUTTON_0, false, BUTTON_PULL, bsp_button_event_handler},

#endif // BUTTON_0

#ifdef BSP_BUTTON_1

{BSP_BUTTON_1, false, BUTTON_PULL, bsp_button_event_handler},

#endif // BUTTON_1

#ifdef BSP_BUTTON_2

{BSP_BUTTON_2, false, BUTTON_PULL, bsp_button_event_handler},

#endif // BUTTON_2

I have uploaded my code to the github, the example I use is in _nRF52805/nRF5_SDK_17.0.2_d674dde/examples/ble_peripheral/ble_app_hids_mouse/pca10040e_nrf52805 v1.05/s112/arm5_no_packs/

The address of my code in github is https://github.com/1436294280/_nRF52805

Best regards

RE: button interruption in nRF52805

Edvin — Tue, 05 Jan 2021 08:13:28 GMT

Hello,

Are the button pins connected to anything, or are the pins floating?

Do you have a define called BUTTON_PULL in the same file as your BUTTON_START definition? What is it set to?

The BSP library is handling the logic around button presses, but the buttons are actually set up using app_button_init(), which is called in bsp_init() in bsp.c. It uses the array called app_buttons in the example that you refer to. What does that look like in your case?

Best regards,

Edvin

RE: button interruption in nRF52805

ticture — Mon, 04 Jan 2021 15:27:08 GMT

the example I use is nRF5SDK1702d674dde\nRF5_SDK_17.0.2_d674dde\examples\ble_peripheral\ble_app_hids_mouse\pca10040e\s112\arm5_no_packs