How can I connect multiple buttons and LEDs to a BLE device from nrf5340dk?

RE: How can I connect multiple buttons and LEDs to a BLE device from nrf5340dk?

Menon — Thu, 28 Sep 2023 09:14:00 GMT

Hello,

I'm happy to hear that. Let me know if you have any doubts, or you can create new tickets if you come across any issues during the development.

Kind Regards,

Abhijith

RE: How can I connect multiple buttons and LEDs to a BLE device from nrf5340dk?

gap_guillen — Thu, 28 Sep 2023 05:06:12 GMT

Thanks for sharing this interesting tutorial. I will follow your advice, so I will repeat the experience of all the lessons and then I will comment my opinion. At first sight, I think this clarifies my big doubts for the moment.

Kind regards,

Guillermo

RE: How can I connect multiple buttons and LEDs to a BLE device from nrf5340dk?

Menon — Wed, 27 Sep 2023 09:48:03 GMT

Hello,

Peripheral_lbs is a good starting point or reference template for your use case, but I recommend you go through this tutorial, which explains more about the GATT API and custom services and characteristics. The sample is very similar to peripheral_lbs, but here it demonstrates how these services and characteristics are made. Please see how the characteristics work and how this controls the LED. I recommend you follow the whole lesson (lesson 4) to get a better understanding of this. Let me know if this clears some of your doubts or if you are still struggling.

Kind Regards,

Abhijith

RE: How can I connect multiple buttons and LEDs to a BLE device from nrf5340dk?

gap_guillen — Thu, 21 Sep 2023 04:35:07 GMT

Hi Abhijith,

Thanks for your answer, I didn't know the details of the DK buttons and LED library. I give you more details of what I want to do:

1. My idea is to control two speeds and the turn OFF of a fan via Bluetooth with the nRF5340DK or any Nordic board. I also want to know if there is electrical power through buttons activated by relays or mosfets. The nRF Connect app connects with the lbs_peripheral project to monitor a button, and to turn ON/OFF an LED on the board.

2. I want to modify this demo to control 3 ports of the nRF5340DK board: Port 1 to turn OFF the fan, port 2 for low speed, and port 3 for high speed.

3. First, I have experimented with turning two LEDs on and off, but I have not had success. For example this code:

#define USER_LED2                DK_LED4
static void app_led_cb(bool led_state)
{
dk_set_led(USER_LED, led_state);
dk_set_led(USER_LED2, led_state);
}

The app only detects one LED, and I want it to detect and control 2 LEDs.

Conclusion this only serves to turn on or off two LEDs simultaneously.

4. Also for monitoring two buttons. I have done this:

#define USER_BUTTON             DK_BTN1_MSK
#define BUTTON_2             	DK_BTN2_MSK 

static void button_changed(uint32_t button_state, uint32_t has_changed)
{
	if (has_changed & USER_BUTTON) {
		uint32_t user_button_state = button_state & USER_BUTTON;

		bt_lbs_send_button_state(user_button_state);
		app_button_state = user_button_state ? true : false;
	}

	if (has_changed & BUTTON_2) {
		uint32_t user_button_state_2 = button_state & BUTTON_2;

		bt_lbs_send_button_state(user_button_state_2);
		app_button_state_2 = user_button_state_2 ? true : false;
	}

}

When I press button 1 or button 2, the app detects as if I pressed a single button. It doesn't tell me which button I pressed.

I hope I have clarified what I want to do. Now, I want to know what I'm doing wrong? Is it possible or not possible to make my idea with the nRF5340DK board?

Regards,

Guillermo

RE: How can I connect multiple buttons and LEDs to a BLE device from nrf5340dk?

Menon — Tue, 19 Sep 2023 13:22:07 GMT

Hello,

In peripheral_lbs sample LED button service is used to receive information about the state of an LED and send a notification to the mobile app when the button is pressed (when the state changes). For this service, the DK buttons and LEDs library has been used in the sample. You can actually change the LEDs or buttons in the development kit depending on your use case. Take a look at the function dk_set_led, which is used to set only a single LED value, which is used inside this sample.

Could you explain the use case a bit more? Do you want to read two-button state changes and include two LEDs? For doing this, I don't think you need to modify the mobile application to include the two buttons or two LEDs, as it is BLE service-based.

Kind Regards.

Abhijith