Hello, I have a little problem. I have no idea about programming, but I would like to improve the project I am using. The project concerns the control of a 4-channel switch connected to the fan via a heart rate monitor. Everything works great, with one exception. I have no information whether the connection to HRM has been initiated. As far as I know, my board has a built-in LED. I would like the built-in LED to turn on when I connect to the BLE heart rate monitor (there are two built-in LEDs on the board, one is normally on and indicates power, the other is off).
Unfortunately, I have no idea how to write such code. Please help. Thank you in advance.
Below I have attached the code that controls the device.
/**
* A modified BLE client that will read BLE HRM
* and control a relay
* author Andrew Grabbs
*/
#include "BLEDevice.h"
//#include "BLEScan.h"
// Set to true to define Relay as Normally Open (NO)
#define RELAY_NO true
// Set number of relays
#define NUM_RELAYS 3
// Heart Rate Zones
#define ZONE_1 155 // 136 bpm
#define ZONE_2 169 // 155 bpm
#define ZONE_3 199 // 169 bpm
// Assign each GPIO to a relay
uint8_t relayGPIOs[NUM_RELAYS] = {25, 26, 27};
// The remote service we wish to connect to.
static BLEUUID serviceUUID("0000180d-0000-1000-8000-00805f9b34fb");
// The characteristic of the remote service we are interested in.
static BLEUUID charUUID(BLEUUID((uint16_t)0x2A37));
//0x2A37
static boolean doConnect = false;
static boolean connected = false;
static boolean notification = false;
static boolean doScan = false;
static BLERemoteCharacteristic* pRemoteCharacteristic;
static BLEAdvertisedDevice* myDevice;
static void notifyCallback(
BLERemoteCharacteristic* pBLERemoteCharacteristic,
uint8_t* pData,
size_t length,
bool isNotify) {
Serial.print("Heart Rate: ");
Serial.print(pData[1], DEC);
Serial.println("bpm");
if(pData[1] <= 135) {
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
}
else if(pData[1] <= ZONE_1 && pData[1] > 136) {
Serial.println("ZONE 1!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[0], LOW);
}
else if(pData[1] > ZONE_1 && pData[1] <= ZONE_2) {
Serial.println("ZONE 2!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[1], LOW);
}
else if(pData[1] > ZONE_2) {
Serial.println("ZONE 3!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[2], LOW);
}
}
class MyClientCallback : public BLEClientCallbacks {
void onConnect(BLEClient* pclient) {
}
void onDisconnect(BLEClient* pclient) {
connected = false;
Serial.println("onDisconnect");
}
};
bool connectToServer() {
Serial.print("Forming a connection to ");
Serial.println(myDevice->getAddress().toString().c_str());
BLEClient* pClient = BLEDevice::createClient();
Serial.println(" - Created client");
pClient->setClientCallbacks(new MyClientCallback());
// Connect to the remove BLE Server.
pClient->connect(myDevice); // if you pass BLEAdvertisedDevice instead of address, it will be recognized type of peer device address (public or private)
Serial.println(" - Connected to server");
// Obtain a reference to the service we are after in the remote BLE server.
BLERemoteService* pRemoteService = pClient->getService(serviceUUID);
if (pRemoteService == nullptr) {
Serial.print("Failed to find our service UUID: ");
Serial.println(serviceUUID.toString().c_str());
pClient->disconnect();
return false;
}
Serial.println(" - Found our service");
// Obtain a reference to the characteristic in the service of the remote BLE server.
pRemoteCharacteristic = pRemoteService->getCharacteristic(charUUID);
if (pRemoteCharacteristic == nullptr) {
Serial.print("Failed to find our characteristic UUID: ");
Serial.println(charUUID.toString().c_str());
pClient->disconnect();
return false;
}
Serial.println(" - Found our characteristic");
// Read the value of the characteristic.
if(pRemoteCharacteristic->canRead()) {
std::string value = pRemoteCharacteristic->readValue();
Serial.print("The characteristic value was: ");
Serial.println(value.c_str());
}
if(pRemoteCharacteristic->canNotify())
pRemoteCharacteristic->registerForNotify(notifyCallback);
connected = true;
return true;
}
/**
* Scan for BLE servers and find the first one that advertises the service we are looking for.
*/
class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
/**
* Called for each advertising BLE server.
*/
void onResult(BLEAdvertisedDevice advertisedDevice) {
Serial.print("BLE Advertised Device found: ");
Serial.println(advertisedDevice.toString().c_str());
// We have found a device, let us now see if it contains the service we are looking for.
if (advertisedDevice.haveServiceUUID() && advertisedDevice.isAdvertisingService(serviceUUID)) {
BLEDevice::getScan()->stop();
myDevice = new BLEAdvertisedDevice(advertisedDevice);
doConnect = true;
doScan = true;
} // Found our server
} // onResult
}; // MyAdvertisedDeviceCallbacks
void setup() {
Serial.begin(115200);
Serial.println("Starting Arduino BLE Client application...");
BLEDevice::init("");
// Set all relays to off when the program starts - if set to Normally Open (NO), the relay is off when you set the relay to HIGH
for(int i=1; i<=NUM_RELAYS; i++){
pinMode(relayGPIOs[i-1], OUTPUT);
if(RELAY_NO){
digitalWrite(relayGPIOs[i-1], HIGH);
}
else{
digitalWrite(relayGPIOs[i-1], LOW);
}
}
// Retrieve a Scanner and set the callback we want to use to be informed when we
// have detected a new device. Specify that we want active scanning and start the
// scan to run for 5 seconds.
BLEScan* pBLEScan = BLEDevice::getScan();
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
pBLEScan->setInterval(1349);
pBLEScan->setWindow(449);
pBLEScan->setActiveScan(true);
pBLEScan->start(5, false);
} // End of setup.
// This is the Arduino main loop function.
void loop() {
// If the flag "doConnect" is true then we have scanned for and found the desired
// BLE Server with which we wish to connect. Now we connect to it. Once we are
// connected we set the connected flag to be true.
if (doConnect == true) {
if (connectToServer()) {
Serial.println("We are now connected to the BLE Server.");
} else {
Serial.println("We have failed to connect to the server; there is nothin more we will do.");
}
doConnect = false;
}
// If we are connected to a peer BLE Server, update the characteristic each time we are reached
// with the current time since boot.
if (connected) {
if (notification == false) {
Serial.println("Turning Notification On");
const uint8_t onPacket[] = {0x01, 0x0};
pRemoteCharacteristic->getDescriptor(BLEUUID((uint16_t)0x2902))->writeValue((uint8_t*)onPacket, 2, true);
notification = true;
}
}else if(doScan){
BLEDevice::getScan()->start(0); // this is just eample to start scan after disconnect, most likely there is better way to do it in arduino
}
delay(1000); // Delay a second between loops.
} // End of loop
/**
* A modified BLE client that will read BLE HRM
* and control a relay
* author Andrew Grabbs
*/
#include "BLEDevice.h"
//#include "BLEScan.h"
// Set to true to define Relay as Normally Open (NO)
#define RELAY_NO true
// Set number of relays
#define NUM_RELAYS 3
// Heart Rate Zones
#define ZONE_1 155 // 136 bpm
#define ZONE_2 169 // 155 bpm
#define ZONE_3 199 // 169 bpm
// Assign each GPIO to a relay
uint8_t relayGPIOs[NUM_RELAYS] = {25, 26, 27};
// The remote service we wish to connect to.
static BLEUUID serviceUUID("0000180d-0000-1000-8000-00805f9b34fb");
// The characteristic of the remote service we are interested in.
static BLEUUID charUUID(BLEUUID((uint16_t)0x2A37));
//0x2A37
static boolean doConnect = false;
static boolean connected = false;
static boolean notification = false;
static boolean doScan = false;
static BLERemoteCharacteristic* pRemoteCharacteristic;
static BLEAdvertisedDevice* myDevice;
static void notifyCallback(
BLERemoteCharacteristic* pBLERemoteCharacteristic,
uint8_t* pData,
size_t length,
bool isNotify) {
Serial.print("Heart Rate: ");
Serial.print(pData[1], DEC);
Serial.println("bpm");
if(pData[1] <= 135) {
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
}
else if(pData[1] <= ZONE_1 && pData[1] > 136) {
Serial.println("ZONE 1!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[0], LOW);
}
else if(pData[1] > ZONE_1 && pData[1] <= ZONE_2) {
Serial.println("ZONE 2!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[1], LOW);
}
else if(pData[1] > ZONE_2) {
Serial.println("ZONE 3!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[2], LOW);
}
}
class MyClientCallback : public BLEClientCallbacks {
void onConnect(BLEClient* pclient) {
digitalWrite(LED_BUILTIN, HIGH);
}
void onDisconnect(BLEClient* pclient) {
connected = false;
Serial.println("onDisconnect");
}
};
bool connectToServer() {
Serial.print("Forming a connection to ");
Serial.println(myDevice->getAddress().toString().c_str());
BLEClient* pClient = BLEDevice::createClient();
Serial.println(" - Created client");
pClient->setClientCallbacks(new MyClientCallback());
// Connect to the remove BLE Server.
pClient->connect(myDevice); // if you pass BLEAdvertisedDevice instead of address, it will be recognized type of peer device address (public or private)
Serial.println(" - Connected to server");
// Obtain a reference to the service we are after in the remote BLE server.
BLERemoteService* pRemoteService = pClient->getService(serviceUUID);
if (pRemoteService == nullptr) {
Serial.print("Failed to find our service UUID: ");
Serial.println(serviceUUID.toString().c_str());
pClient->disconnect();
return false;
}
Serial.println(" - Found our service");
// Obtain a reference to the characteristic in the service of the remote BLE server.
pRemoteCharacteristic = pRemoteService->getCharacteristic(charUUID);
if (pRemoteCharacteristic == nullptr) {
Serial.print("Failed to find our characteristic UUID: ");
Serial.println(charUUID.toString().c_str());
pClient->disconnect();
return false;
}
Serial.println(" - Found our characteristic");
// Read the value of the characteristic.
if(pRemoteCharacteristic->canRead()) {
std::string value = pRemoteCharacteristic->readValue();
Serial.print("The characteristic value was: ");
Serial.println(value.c_str());
}
if(pRemoteCharacteristic->canNotify())
pRemoteCharacteristic->registerForNotify(notifyCallback);
connected = true;
return true;
}
/**
* Scan for BLE servers and find the first one that advertises the service we are looking for.
*/
class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
/**
* Called for each advertising BLE server.
*/
void onResult(BLEAdvertisedDevice advertisedDevice) {
Serial.print("BLE Advertised Device found: ");
Serial.println(advertisedDevice.toString().c_str());
// We have found a device, let us now see if it contains the service we are looking for.
if (advertisedDevice.haveServiceUUID() && advertisedDevice.isAdvertisingService(serviceUUID)) {
BLEDevice::getScan()->stop();
myDevice = new BLEAdvertisedDevice(advertisedDevice);
doConnect = true;
doScan = true;
} // Found our server
} // onResult
}; // MyAdvertisedDeviceCallbacks
void setup() {
Serial.begin(115200);
Serial.println("Starting Arduino BLE Client application...");
pinMode(LED_BUILTIN, OUTPUT);
digitalWrite(LED_BUILTIN, LOW);
BLEDevice::init("");
// Set all relays to off when the program starts - if set to Normally Open (NO), the relay is off when you set the relay to HIGH
for(int i=1; i<=NUM_RELAYS; i++){
pinMode(relayGPIOs[i-1], OUTPUT);
if(RELAY_NO){
digitalWrite(relayGPIOs[i-1], HIGH);
}
else{
digitalWrite(relayGPIOs[i-1], LOW);
}
}
// Retrieve a Scanner and set the callback we want to use to be informed when we
// have detected a new device. Specify that we want active scanning and start the
// scan to run for 5 seconds.
BLEScan* pBLEScan = BLEDevice::getScan();
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
pBLEScan->setInterval(1349);
pBLEScan->setWindow(449);
pBLEScan->setActiveScan(true);
pBLEScan->start(5, false);
} // End of setup.
// This is the Arduino main loop function.
void loop() {
// If the flag "doConnect" is true then we have scanned for and found the desired
// BLE Server with which we wish to connect. Now we connect to it. Once we are
// connected we set the connected flag to be true.
if (doConnect == true) {
if (connectToServer()) {
Serial.println("We are now connected to the BLE Server.");
} else {
Serial.println("We have failed to connect to the server; there is nothin more we will do.");
}
doConnect = false;
}
// If we are connected to a peer BLE Server, update the characteristic each time we are reached
// with the current time since boot.
if (connected) {
if (notification == false) {
Serial.println("Turning Notification On");
const uint8_t onPacket[] = {0x01, 0x0};
pRemoteCharacteristic->getDescriptor(BLEUUID((uint16_t)0x2902))->writeValue((uint8_t*)onPacket, 2, true);
notification = true;
}
}else if(doScan){
BLEDevice::getScan()->start(0); // this is just eample to start scan after disconnect, most likely there is better way to do it in arduino
}
delay(1000); // Delay a second between loops.
} // End of loop
Thank you. The compiler showed me errors. But your previous post was a great tip. I modified the code a bit (based on ESP32 LED Blink Example | Circuits4you.com) and...... IT WORKS.
/**
* A modified BLE client that will read BLE HRM
* and control a relay
* author Andrew Grabbs
*/
#include "BLEDevice.h"
//#include "BLEScan.h"
#define LED 2
// Set to true to define Relay as Normally Open (NO)
#define RELAY_NO true
// Set number of relays
#define NUM_RELAYS 3
// Heart Rate Zones
#define ZONE_1 155 // 136 bpm
#define ZONE_2 169 // 155 bpm
#define ZONE_3 199 // 169 bpm
// Assign each GPIO to a relay
uint8_t relayGPIOs[NUM_RELAYS] = {25, 26, 27};
// The remote service we wish to connect to.
static BLEUUID serviceUUID("0000180d-0000-1000-8000-00805f9b34fb");
// The characteristic of the remote service we are interested in.
static BLEUUID charUUID(BLEUUID((uint16_t)0x2A37));
//0x2A37
static boolean doConnect = false;
static boolean connected = false;
static boolean notification = false;
static boolean doScan = false;
static BLERemoteCharacteristic* pRemoteCharacteristic;
static BLEAdvertisedDevice* myDevice;
static void notifyCallback(
BLERemoteCharacteristic* pBLERemoteCharacteristic,
uint8_t* pData,
size_t length,
bool isNotify) {
Serial.print("Heart Rate: ");
Serial.print(pData[1], DEC);
Serial.println("bpm");
if(pData[1] <= 135) {
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
}
else if(pData[1] <= ZONE_1 && pData[1] > 136) {
Serial.println("ZONE 1!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[0], LOW);
}
else if(pData[1] > ZONE_1 && pData[1] <= ZONE_2) {
Serial.println("ZONE 2!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[1], LOW);
}
else if(pData[1] > ZONE_2) {
Serial.println("ZONE 3!");
for(int i=1; i<=NUM_RELAYS; i++){
digitalWrite(relayGPIOs[i-1], HIGH);
}
digitalWrite(relayGPIOs[2], LOW);
}
}
class MyClientCallback : public BLEClientCallbacks {
void onConnect(BLEClient* pclient) {
digitalWrite(LED, HIGH);
}
void onDisconnect(BLEClient* pclient) {
connected = false;
Serial.println("onDisconnect");
}
};
bool connectToServer() {
Serial.print("Forming a connection to ");
Serial.println(myDevice->getAddress().toString().c_str());
BLEClient* pClient = BLEDevice::createClient();
Serial.println(" - Created client");
pClient->setClientCallbacks(new MyClientCallback());
// Connect to the remove BLE Server.
pClient->connect(myDevice); // if you pass BLEAdvertisedDevice instead of address, it will be recognized type of peer device address (public or private)
Serial.println(" - Connected to server");
// Obtain a reference to the service we are after in the remote BLE server.
BLERemoteService* pRemoteService = pClient->getService(serviceUUID);
if (pRemoteService == nullptr) {
Serial.print("Failed to find our service UUID: ");
Serial.println(serviceUUID.toString().c_str());
pClient->disconnect();
return false;
}
Serial.println(" - Found our service");
// Obtain a reference to the characteristic in the service of the remote BLE server.
pRemoteCharacteristic = pRemoteService->getCharacteristic(charUUID);
if (pRemoteCharacteristic == nullptr) {
Serial.print("Failed to find our characteristic UUID: ");
Serial.println(charUUID.toString().c_str());
pClient->disconnect();
return false;
}
Serial.println(" - Found our characteristic");
// Read the value of the characteristic.
if(pRemoteCharacteristic->canRead()) {
std::string value = pRemoteCharacteristic->readValue();
Serial.print("The characteristic value was: ");
Serial.println(value.c_str());
}
if(pRemoteCharacteristic->canNotify())
pRemoteCharacteristic->registerForNotify(notifyCallback);
connected = true;
return true;
}
/**
* Scan for BLE servers and find the first one that advertises the service we are looking for.
*/
class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
/**
* Called for each advertising BLE server.
*/
void onResult(BLEAdvertisedDevice advertisedDevice) {
Serial.print("BLE Advertised Device found: ");
Serial.println(advertisedDevice.toString().c_str());
// We have found a device, let us now see if it contains the service we are looking for.
if (advertisedDevice.haveServiceUUID() && advertisedDevice.isAdvertisingService(serviceUUID)) {
BLEDevice::getScan()->stop();
myDevice = new BLEAdvertisedDevice(advertisedDevice);
doConnect = true;
doScan = true;
} // Found our server
} // onResult
}; // MyAdvertisedDeviceCallbacks
void setup() {
Serial.begin(115200);
Serial.println("Starting Arduino BLE Client application...");
// Set pin mode
pinMode(LED,OUTPUT);
BLEDevice::init("");
// Set all relays to off when the program starts - if set to Normally Open (NO), the relay is off when you set the relay to HIGH
for(int i=1; i<=NUM_RELAYS; i++){
pinMode(relayGPIOs[i-1], OUTPUT);
if(RELAY_NO){
digitalWrite(relayGPIOs[i-1], HIGH);
}
else{
digitalWrite(relayGPIOs[i-1], LOW);
}
}
// Retrieve a Scanner and set the callback we want to use to be informed when we
// have detected a new device. Specify that we want active scanning and start the
// scan to run for 5 seconds.
BLEScan* pBLEScan = BLEDevice::getScan();
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
pBLEScan->setInterval(1349);
pBLEScan->setWindow(449);
pBLEScan->setActiveScan(true);
pBLEScan->start(5, false);
} // End of setup.
// This is the Arduino main loop function.
void loop() {
// If the flag "doConnect" is true then we have scanned for and found the desired
// BLE Server with which we wish to connect. Now we connect to it. Once we are
// connected we set the connected flag to be true.
if (doConnect == true) {
if (connectToServer()) {
Serial.println("We are now connected to the BLE Server.");
} else {
Serial.println("We have failed to connect to the server; there is nothin more we will do.");
}
doConnect = false;
}
// If we are connected to a peer BLE Server, update the characteristic each time we are reached
// with the current time since boot.
if (connected) {
if (notification == false) {
Serial.println("Turning Notification On");
const uint8_t onPacket[] = {0x01, 0x0};
pRemoteCharacteristic->getDescriptor(BLEUUID((uint16_t)0x2902))->writeValue((uint8_t*)onPacket, 2, true);
notification = true;
}
}else if(doScan){
BLEDevice::getScan()->start(0); // this is just eample to start scan after disconnect, most likely there is better way to do it in arduino
}
delay(1000); // Delay a second between loops.
} // End of loop