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// See: https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.service.heart_rate.xml

// Supported Characteristics:

// Name UUID Requirement Properties

// ---------------------------- ------ ----------- ----------

// Heart Rate Measurement 0x2A37 Mandatory Notify

// Body Sensor Location 0x2A38 Optional Read

// Heart Rate Control Point 0x2A39 Conditional Write <-- Not used here

hrms.begin();

// Note: You must call .begin() on the BLEService before calling .begin() on

// any characteristic(s) within that service definition.. Calling .begin() on

// a BLECharacteristic will cause it to be added to the last BLEService that

// was 'begin()'ed!

// Configure the Heart Rate Measurement characteristic

// See: https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.heart_rate_measurement.xml

// Permission = Notify

// Min Len = 1

// Max Len = 8

// B0 = UINT8 - Flag (MANDATORY)

// b5:7 = Reserved

// b4 = RR-Internal (0 = Not present, 1 = Present)

// b3 = Energy expended status (0 = Not present, 1 = Present)

// b1:2 = Sensor contact status (0+1 = Not supported, 2 = Supported but contact not detected, 3 = Supported and detected)

// b0 = Value format (0 = UINT8, 1 = UINT16)

// B1 = UINT8 - 8-bit heart rate measurement value in BPM

// B2:3 = UINT16 - 16-bit heart rate measurement value in BPM

// B4:5 = UINT16 - Energy expended in joules

// B6:7 = UINT16 - RR Internal (1/1024 second resolution)

hrmc.setProperties(CHR_PROPS_NOTIFY);

hrmc.setPermission(SECMODE_OPEN, SECMODE_NO_ACCESS);

hrmc.setFixedLen(2);

hrmc.setCccdWriteCallback(cccd_callback); // Optionally capture CCCD updates

hrmc.begin();

uint8_t hrmdata[2] = { 0b00000110, 0x40 }; // Set the characteristic to use 8-bit values, with the sensor connected and detected

hrmc.notify(hrmdata, 2); // Use .notify instead of .write!

// Configure the Body Sensor Location characteristic

// See: https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.body_sensor_location.xml

// Permission = Read

// Min Len = 1

// Max Len = 1

// B0 = UINT8 - Body Sensor Location

// 0 = Other

// 1 = Chest

// 2 = Wrist

// 3 = Finger

// 4 = Hand

// 5 = Ear Lobe

// 6 = Foot

// 7:255 = Reserved

bslc.setProperties(CHR_PROPS_READ);

bslc.setPermission(SECMODE_OPEN, SECMODE_NO_ACCESS);

bslc.setFixedLen(1);

bslc.begin();

bslc.write8(2); // Set the characteristic to 'Wrist' (2)

}

void connect_callback(void)

{

Serial.println("Connected");