ESP32: GATT通信 (ArduinoBLE.h)

こちらと同様のことを、ArduinoBLE.h を使って行いました。
ESP32: GATT通信

スケッチ例を参考にしました。

プログラム

BatteryMonitor.ino

// ---------------------------------------------------------------
/*
	BatteryMonitor.ino

					Sep/22/2024
*/
// ---------------------------------------------------------------
#include <ArduinoBLE.h>

BLEService batteryService("180F");

BLEUnsignedCharCharacteristic batteryLevelChar("2A19",  // standard 16-bit characteristic UUID
    BLERead | BLENotify); // remote clients will be able to get notifications if this characteristic changes

int icount = 0;
// ---------------------------------------------------------------
void setup() {
	Serial.begin(115200);
	while (!Serial);

	if (!BLE.begin()) {
		Serial.println("starting BLE failed!");

		while (1);
	}

	BLE.setLocalName("BatteryMonitor");
	BLE.setAdvertisedService(batteryService); // add the service UUID
	batteryService.addCharacteristic(batteryLevelChar); // add the battery level characteristic
	BLE.addService(batteryService);

	int oldBatteryLevel = 0;
	batteryLevelChar.writeValue(oldBatteryLevel);

	BLE.advertise();

	Serial.println("Bluetooth® device active, waiting for connections...");
}

// ---------------------------------------------------------------
void loop() {
	Serial.print("*** loop *** ");
	Serial.println(icount);
	icount++;
	delay(1000);
	// wait for a Bluetooth® Low Energy central
	BLEDevice central = BLE.central();

	// if a central is connected to the peripheral:
	if (central) {
		Serial.print("Connected to central: ");
		// print the central's BT address:
		Serial.println(central.address());

		if (central.connected()) {
			updateBatteryLevel();
			}
		}
	else
		{
		Serial.print("Disconnected from central: ");
		Serial.println(central.address());
		}
}

// ---------------------------------------------------------------
void updateBatteryLevel() {
	int batteryLevel = 25 + icount;

	Serial.print("Battery Level % is now: "); // print it
	Serial.println(batteryLevel);

	batteryLevelChar.writeValue(batteryLevel);

}
// ---------------------------------------------------------------

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