I want to create/use multiple uuid to send multiple data from android device to esp32

[patel99]

basically i created code to send data from android mobile to esp32 but it sends to only one ID which is "CHARACTERISTIC_UUID_RX" and i want multiple data to send from my android device to esp32 anyone please help me how to create multiple CHARACTERISTIC_UUID_RX

here is code which i am using it work only single CHARACTERISTIC_UUID_RX i want to add more please tell me how can i do that

/*
    Video: https://www.youtube.com/watch?v=oCMOYS71NIU
    Based on Neil Kolban example for IDF: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLE%20Tests/SampleNotify.cpp
    Ported to Arduin

esp32_ble_arduino_code.ino (5.0 KB)
o ESP32 by Evandro Copercini

Create a BLE server that, once we receive a connection, will send periodic notifications.
The service advertises itself as: 6E400001-B5A3-F393-E0A9-E50E24DCCA9E
Has a characteristic of: 6E400002-B5A3-F393-E0A9-E50E24DCCA9E - used for receiving data with "WRITE"
Has a characteristic of: 6E400003-B5A3-F393-E0A9-E50E24DCCA9E - used to send data with "NOTIFY"

The design of creating the BLE server is:

1. Create a BLE Server
2. Create a BLE Service
3. Create a BLE Characteristic on the Service
4. Create a BLE Descriptor on the characteristic
5. Start the service.
6. Start advertising.

In this example rxValue is the data received (only accessible inside that function).
And txValue is the data to be sent, in this example just a byte incremented every second.
*/
#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>

BLECharacteristic *pCharacteristic;
bool deviceConnected = false;
int txValue = 0;

//defining the service & characteristica

// https://www.uuidgenerator.net/

#define SERVICE_UUID "6E400001-B5A3-F393-E0A9-E50E24DCCA9E" // UART service UUID
#define CHARACTERISTIC_UUID_RX "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
#define CHARACTERISTIC_UUID_TX "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"

class MyServerCallbacks: public BLEServerCallbacks {
void onConnect(BLEServer* pServer) {
deviceConnected = true;
};

void onDisconnect(BLEServer* pServer) {
  deviceConnected = false;
}

};

class MyCallbacks: public BLECharacteristicCallbacks {
void onWrite(BLECharacteristic *pCharacteristic) {
std::string rxValue = pCharacteristic->getValue();

  if(rxValue.length()>0){
    Serial.println("====START=RECEIVE====");
    Serial.print("Received Value:");

    for(int i = 0; i<rxValue.length(); i++){
      Serial.print(rxValue[i]);
      }
      Serial.println();
      Serial.println("===END=RECEIVE===");
    }
}

};

void setup() {
Serial.begin(115200);

// Create the BLE Device
BLEDevice::init("ESP32 UART Test"); // Give it a name

// Create the BLE Server
BLEServer *pServer = BLEDevice::createServer();
pServer->setCallbacks(new MyServerCallbacks());

// Create the BLE Service
BLEService *pService = pServer->createService(SERVICE_UUID);

// Create a BLE Characteristic
pCharacteristic = pService->createCharacteristic(
CHARACTERISTIC_UUID_TX,
BLECharacteristic::PROPERTY_NOTIFY
);

pCharacteristic->addDescriptor(new BLE2902());
//CHAR. FOR RECEIVING END
BLECharacteristic *pCharacteristic = pService->createCharacteristic(
CHARACTERISTIC_UUID_RX,
BLECharacteristic::PROPERTY_WRITE
);

pCharacteristic->setCallbacks(new MyCallbacks());

// Start the service
pService->start();

// Start advertising
pServer->getAdvertising()->start();
Serial.println("Waiting a client connection to notify...");
}

void loop() {

delay(1000);
}

[UKHeliBob]

Please clarify exactly which version of the IDE you are using

[patel99]

I am using arduino ide version1.8.13

[UKHeliBob]

Your post was MOVED to its current location as it is more suitable.

Could you also take a few moments to Learn How To Use The Forum.

Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum in the future.

[patel99]

I want to create 3 Ble characteristic UUID to receive different data from android mobile here is example code i try but it does not work.

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>

// See the following for generating UUIDs:
// https://www.uuidgenerator.net/

#define SERVICE_UUID "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define CHARACTERISTIC1_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"
#define CHARACTERISTIC2_UUID "688091db-1736-4179-b7ce-e42a724a6a68"
#define CHARACTERISTIC3_UUID "0515e27d-dd91-4f96-9452-5f43649c1819"

void setup() {
Serial.begin(115200);
Serial.println("Starting BLE work!");

BLEDevice::init("MyESP32");
BLEServer *pServer = BLEDevice::createServer();
BLEService *pService = pServer->createService(SERVICE_UUID);
BLECharacteristic *pCharacteristic1 = pService->createCharacteristic(
CHARACTERISTIC1_UUID,
BLECharacteristic::PROPERTY_READ |
BLECharacteristic::PROPERTY_WRITE
);
pCharacteristic1->setValue("Hi 1");

BLECharacteristic *pCharacteristic2 = pService->createCharacteristic(
CHARACTERISTIC2_UUID,
BLECharacteristic::PROPERTY_READ |
BLECharacteristic::PROPERTY_WRITE
);
pCharacteristic2->setValue("Hi 2");

BLECharacteristic *pCharacteristic3 = pService->createCharacteristic(
CHARACTERISTIC3_UUID,
BLECharacteristic::PROPERTY_READ |
BLECharacteristic::PROPERTY_WRITE
);
pCharacteristic3->setValue("Hi 3");

pService->start();
BLEAdvertising *pAdvertising = pServer->getAdvertising();
pAdvertising->start();
Serial.println("3 Characteristics defined! Now you can read it in your phone!");
}

void loop() {
// put your main code here, to run repeatedly:
delay(2000);
}