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/*********************************************************************
This is an example for our nRF52 based Bluefruit LE modules
Pick one up today in the adafruit shop!
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
MIT license, check LICENSE for more information
All text above, and the splash screen below must be included in
any redistribution
*********************************************************************/
#include <bluefruit.h>
/* HRM Service Definitions
* Heart Rate Monitor Service: 0x180D
* Heart Rate Measurement Char: 0x2A37
* Body Sensor Location Char: 0x2A38
*/
BLEService hrms = BLEService(UUID16_SVC_HEART_RATE);
BLECharacteristic hrmc = BLECharacteristic(UUID16_CHR_HEART_RATE_MEASUREMENT);
BLECharacteristic bslc = BLECharacteristic(UUID16_CHR_BODY_SENSOR_LOCATION);
BLEDis bledis; // DIS (Device Information Service) helper class instance
BLEBas blebas; // BAS (Battery Service) helper class instance
uint8_t bps = 0;
void setup()
{
Serial.begin(115200);
while ( !Serial ) delay(10); // for nrf52840 with native usb
Serial.println("Bluefruit52 HRM Example");
Serial.println("-----------------------\n");
// Initialise the Bluefruit module
Serial.println("Initialise the Bluefruit nRF52 module");
Bluefruit.begin();
// Set the advertised device name (keep it short!)
Serial.println("Setting Device Name to 'Feather52 HRM'");
Bluefruit.setName("Bluefruit52 HRM");
// Set the connect/disconnect callback handlers
Bluefruit.setConnectCallback(connect_callback);
Bluefruit.setDisconnectCallback(disconnect_callback);
// Configure and Start the Device Information Service
Serial.println("Configuring the Device Information Service");
bledis.setManufacturer("Adafruit Industries");
bledis.setModel("Bluefruit Feather52");
bledis.begin();
// Start the BLE Battery Service and set it to 100%
Serial.println("Configuring the Battery Service");
blebas.begin();
blebas.write(100);
// Setup the Heart Rate Monitor service using
// BLEService and BLECharacteristic classes
Serial.println("Configuring the Heart Rate Monitor Service");
setupHRM();
// Setup the advertising packet(s)
Serial.println("Setting up the advertising payload(s)");
startAdv();
Serial.println("Ready Player One!!!");
Serial.println("\nAdvertising");
}
void startAdv(void)
{
// Advertising packet
Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
Bluefruit.Advertising.addTxPower();
// Include HRM Service UUID
Bluefruit.Advertising.addService(hrms);
// Include Name
Bluefruit.Advertising.addName();
/* Start Advertising
* - Enable auto advertising if disconnected
* - Interval: fast mode = 20 ms, slow mode = 152.5 ms
* - Timeout for fast mode is 30 seconds
* - Start(timeout) with timeout = 0 will advertise forever (until connected)
*
* For recommended advertising interval
* https://developer.apple.com/library/content/qa/qa1931/_index.html
*/
Bluefruit.Advertising.restartOnDisconnect(true);
Bluefruit.Advertising.setInterval(32, 244); // in unit of 0.625 ms
Bluefruit.Advertising.setFastTimeout(30); // number of seconds in fast mode
Bluefruit.Advertising.start(0); // 0 = Don't stop advertising after n seconds
}
void setupHRM(void)
{
// Configure the Heart Rate Monitor service
// 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
// Properties = 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
// Properties = 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(uint16_t conn_handle)
{
char central_name[32] = { 0 };
Bluefruit.Gap.getPeerName(conn_handle, central_name, sizeof(central_name));
Serial.print("Connected to ");
Serial.println(central_name);
}
/**
* Callback invoked when a connection is dropped
* @param conn_handle connection where this event happens
* @param reason is a BLE_HCI_STATUS_CODE which can be found in ble_hci.h
* https://github.com/adafruit/Adafruit_nRF52_Arduino/blob/master/cores/nRF5/nordic/softdevice/s140_nrf52_6.1.1_API/include/ble_hci.h
*/
void disconnect_callback(uint16_t conn_handle, uint8_t reason)
{
(void) conn_handle;
(void) reason;
Serial.println("Disconnected");
Serial.println("Advertising!");
}
void cccd_callback(BLECharacteristic& chr, uint16_t cccd_value)
{
// Display the raw request packet
Serial.print("CCCD Updated: ");
//Serial.printBuffer(request->data, request->len);
Serial.print(cccd_value);
Serial.println("");
// Check the characteristic this CCCD update is associated with in case
// this handler is used for multiple CCCD records.
if (chr.uuid == hrmc.uuid) {
if (chr.notifyEnabled()) {
Serial.println("Heart Rate Measurement 'Notify' enabled");
} else {
Serial.println("Heart Rate Measurement 'Notify' disabled");
}
}
}
void loop()
{
digitalToggle(LED_RED);
if ( Bluefruit.connected() ) {
uint8_t hrmdata[2] = { 0b00000110, bps++ }; // Sensor connected, increment BPS value
// Note: We use .notify instead of .write!
// If it is connected but CCCD is not enabled
// The characteristic's value is still updated although notification is not sent
if ( hrmc.notify(hrmdata, sizeof(hrmdata)) ){
Serial.print("Heart Rate Measurement updated to: "); Serial.println(bps);
}else{
Serial.println("ERROR: Notify not set in the CCCD or not connected!");
}
}
// Only send update once per second
delay(1000);
}
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