NRF52840 BLE LED/Button Pairing

[tsroga]

Hello. 

I am modifying the nRF52840DK NRF desktop firmware for a custom mouse application. Using the standard firmware, LED2 is used as the status LED for connectivity. What is the best way to reconfigure the status LED (LED3 or LED4)? I can't find any setting in the nRF Kconfig GUI. Also, is there any way to reconfigure other buttons as the peer control? 

Thank you.

[Albert_0]

Hi,

I believe you have to do it in the .dts file for your project. The board or your project would have an LED2 section as "gpio-led" in the board's DTS file. You can still name it LED2 but change the pin assignment and re-build. Or you can add a new LED3/4 in your DTS file following the same conventions as LED2, configure LED3/4 instead of LED2 in your source, and rebuild.

Example:

board_device_tree.dts

/ { 
	leds {
	compatible = "gpio-leds";

	led1: led_1{
		gpios = < &gpio0 24 GPIO_ACTIVE_HIGH>;
		label = "Green LED";
	};

	led2: led_2{
		gpios = < &gpio1 16 GPIO_ACTIVE_HIGH>;
		label = "Blue LED";
	};
}

led.c:

/* The devicetree node identifier for the leds. */
#define LED_GREEN_NODE DT_NODELABEL(led1)
#define LED_BLUE_NODE DT_NODELABEL(led2)

static const struct gpio_dt_spec led_green = GPIO_DT_SPEC_GET(LED_GREEN_NODE, gpios);
static const struct gpio_dt_spec led_blue = GPIO_DT_SPEC_GET(LED_BLUE_NODE, gpios);

K_THREAD_DEFINE(green_blinky_tid, LED_STACKSIZE, green_blinky, NULL, NULL, NULL, 2, 0, 0);
K_THREAD_DEFINE(blue_blinky_tid, LED_STACKSIZE, blue_blinky, NULL, NULL, NULL, 2, 0, 0);

void green_blinky(void)
{
	int ret; 
	
	gpio_pin_configure_dt(&led_green, GPIO_OUTPUT_ACTIVE);

	if (!gpio_is_ready_dt(&led_green))
	{
		return;
	}

	while (1)
	{
		ret = gpio_pin_toggle_dt(&led_green);
		if (ret < 0) {
			return;
		}
		k_msleep(SLEEP_TIME_MS);
	}
	return;

}

void blue_blinky(void)
{
	int ret;
	
	gpio_pin_configure_dt(&led_blue, GPIO_OUTPUT_ACTIVE);

	if (!gpio_is_ready_dt(&led_blue))
	{
		return;
	}

	while (1)
	{
		ret = gpio_pin_toggle_dt(&led_blue);
		if (ret < 0) {
			return;
		}
		k_msleep(SLEEP_TIME_MS / 2);
	}
	return;
}

Something along those lines.

Cheers,

Alberto