How to set XIAO nRF54L15 button

Community
,
1

Hello,

I see that button 3 is used in the Matter examples (contact_sensor).

#define UAT_BUTTON_MASK DK_BTN3_MSK

I would like to know how to configure either:

  • the button built into the board
  • another button connected to a GPIO

Should I add a new def in xiao_nrf54l15_nrf54l15_cpuapp.overlay file?

    buttons {
        compatible = "gpio-keys"; // Use "gpio-keys" for button input handling
        xiao_button: button_3 {
            gpios = <&xiao_d 3 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
            zephyr,code = <INPUT_KEY_3>;
        };
    };
2

I dont think you can use the button on the board because they are hard wired to the reset and boot triggers…

3

So I would use expansion board User button (D1 pin) or a custom button (D3 pin).

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4

the button on the left is the reset button… same as the reset button on the board… it was made for the original SAMD that did not have a reset button on board the user button is on D1

if you are using the expansion board you can use Grove - Dual Button - Seeed Studio

If you read this part about strapping pins and understand you may be able to get the boot button to function as a user button, but the reset pin as i understand pulls directly to ground in hardware

5

There is an User button (D1 pin) with expansion board:

image
image698Ă—766 95.8 KB

6

Yes actually 2 buttons… as you noted the user button is on the right… the reset button is on the left… I was just
Making that distinction

1 Like
7

Hi there,

So there are a couple ways (2) AFAIK, use “&xiao_d” for the “D Pins” with these, “the SILK pins” :grin: i.e. the diagram pic or the
GPIO’s “&gpio0<pin…>”

on the XIAO nRF54L15 Sense the mappings are:

Below is a clean Zephyr setup that replaces the DK button masks and gives you debounced events for both buttons via gpio-keys.

1) Devicetree overlay

Create boards/xiao_nrf54l15_nrf54l15_cpuapp.overlay (or your app’s overlay) with:

/ {
    aliases {
        sw0 = &user_btn;   /* USER button (P0.00) */
        sw1 = &ext_btn;    /* External button on D0 (P1.04) */
    };

    buttons: buttons {
        compatible = "gpio-keys";

        /* On-board USER button: P0.00 → GND (pull-up, active-low) */
        user_btn: user_btn {
            gpios = <&gpio0 0 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
            label = "USER_BUTTON_P0_00";
            zephyr,code = <INPUT_KEY_0>;
        };

        /* External button on D0: P1.04 → GND (pull-up, active-low) */
        ext_btn: ext_btn {
            gpios = <&gpio1 4 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
            label = "EXT_BUTTON_D0_P1_04";
            zephyr,code = <INPUT_KEY_1>;
        };
    };
};

2) prj.conf

Enable the input stack and gpio-keys (and stop using the DK helper):

CONFIG_GPIO=y
CONFIG_INPUT=y
CONFIG_INPUT_GPIO_KEYS=y
CONFIG_DK_LIBRARY=n

3) Minimal app code (works great for Matter samples too)

// src/main.c
#include <zephyr/kernel.h>
#include <zephyr/input/input.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(app, LOG_LEVEL_INF);

static void input_cb(const struct device *dev, struct input_event *evt)
{
    if (evt->type != INPUT_EV_KEY) return;
    const bool pressed = (evt->value != 0);

    switch (evt->code) {
    case INPUT_KEY_0: // USER (P0.00)
        LOG_INF("USER (P0.00) %s", pressed ? "pressed" : "released");
        /* TODO: in Matter contact_sensor, flip contact attribute here */
        break;
    case INPUT_KEY_1: // D0 (P1.04)
        LOG_INF("D0 (P1.04) %s", pressed ? "pressed" : "released");
        break;
    default:
        break;
    }
}

INPUT_CALLBACK_DEFINE(NULL, input_cb);

int main(void)
{
    LOG_INF("Buttons ready: USER=P0.00 (INPUT_KEY_0), D0=P1.04 (INPUT_KEY_1)");
    while (1) { k_sleep(K_SECONDS(1)); }
}

Hookup reality (no hand-waving)

  • USER button is already wired to GND on the board—keep GPIO_PULL_UP | GPIO_ACTIVE_LOW. Seeed Studio Files+1
  • D0 external button: wire D0 → switch → GND; no external resistor needed (we enable the internal pull-up). D0 maps to P1.04. Seeed Studio Files
  • Boot-time safety: Using D0 at runtime is fine. Just don’t hold it asserted at reset if any boot strap is ever assigned to that pad in other firmware.

I like using the onboard buttons, why NOT ? just don’t mess with them at boot time as always. I don’t like them location wise though, "Best in Button Class " goes to the C3 :grin: IMO.

HTH
GL :slight_smile: PJ :v:

2 Likes
8

Thanks for all these detailed examples. I’ll give it a try :slight_smile:

1 Like