should be possible
initially try this BLE_chat program which is based on the File>Examples>BLE>UART
Using Arduino IDE V 2.3.5 ESP32 core 3.3.0 and running on a Heltec LoRa V3 with Tools>Board Heltec WiFi LoRa (V3) selected
// BLE chat program adapted from File>Examples>BLE>UART
// run terminal app on smartphone and exchange test messages
// e.g. Android https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_terminal&hl=en-US
/*
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 Arduino 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>
BLEServer *pServer = NULL;
BLECharacteristic *pTxCharacteristic;
bool deviceConnected = false;
bool oldDeviceConnected = false;
uint8_t txValue = 0;
// See the following for generating UUIDs:
// 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) {
String rxValue = pCharacteristic->getValue();
if (rxValue.length() > 0) {
Serial.println("*********");
Serial.print("Received Value: ");
for (int i = 0; i < rxValue.length(); i++)
Serial.print(rxValue[i]);
Serial.println();
Serial.println("*********");
}
}
};
void setup() {
Serial.begin(115200);
// Create the BLE Device
BLEDevice::init("UART Service");
// Create the BLE Server
pServer = BLEDevice::createServer();
pServer->setCallbacks(new MyServerCallbacks());
// Create the BLE Service
BLEService *pService = pServer->createService(SERVICE_UUID);
// Create a BLE Characteristic
pTxCharacteristic = pService->createCharacteristic(
CHARACTERISTIC_UUID_TX,
BLECharacteristic::PROPERTY_NOTIFY);
pTxCharacteristic->addDescriptor(new BLE2902());
BLECharacteristic *pRxCharacteristic = pService->createCharacteristic(
CHARACTERISTIC_UUID_RX,
BLECharacteristic::PROPERTY_WRITE);
pRxCharacteristic->setCallbacks(new MyCallbacks());
// Start the service
pService->start();
// Start advertising
pServer->getAdvertising()->start();
Serial.println("Waiting a client connection to notify...");
}
void loop() {
if (deviceConnected) {
if (Serial.available()) {
byte text[100] = { 0 };
int size = Serial.readBytes( text, 100);
pTxCharacteristic->setValue(text, size);
pTxCharacteristic->notify();
txValue++;
delay(10); // bluetooth stack will go into congestion, if too many packets are sent
}
}
// disconnecting
if (!deviceConnected && oldDeviceConnected) {
delay(500); // give the bluetooth stack the chance to get things ready
pServer->startAdvertising(); // restart advertising
Serial.println("start advertising");
oldDeviceConnected = deviceConnected;
}
// connecting
if (deviceConnected && !oldDeviceConnected) {
// do stuff here on connecting
oldDeviceConnected = deviceConnected;
}
}
paired Android phone with “UART service” and ran Serial Bluetooth Terminal
under Devices select Bluetooth LE then UART Service, e.g. screen
the Heltec V3 serial monitor displays
Waiting a client connection to notify...
*********
Received Value: fhgtyhghjuyyiyuuuui
*********
*********
Received Value: fhgtyhghjuyyiyuuuui
*********
*********
Received Value: hello from android
*********
*********
Received Value: hello from android
will see if I can get it working with LoRa
