I have been trying for days to connect my ESP32 S3 to a my computer (MacBook Pro M1/macOS Sequoia) via bluetooth low energy, but it simply does not work. Could anybody help me with an example or instructions. Those are the codes that I am currently using:
ESP32 code:
#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>
// Define UUIDs for the service and characteristic
#define SERVICE_UUID "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"
BLEServer* pServer = NULL;
BLECharacteristic* pCharacteristic = NULL;
bool deviceConnected = false;
int counter = 0;
class MyServerCallbacks: public BLEServerCallbacks {
void onConnect(BLEServer* pServer) {
deviceConnected = true;
Serial.println("Device connected");
};
void onDisconnect(BLEServer* pServer) {
deviceConnected = false;
Serial.println("Device disconnected");
// Restart advertising when disconnected
BLEDevice::startAdvertising();
}
};
void setup() {
Serial.begin(115200);
Serial.println("Starting BLE Counter Service...");
// Create the BLE Device
BLEDevice::init("ESP32-Counter");
// 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
pCharacteristic = pService->createCharacteristic(
CHARACTERISTIC_UUID,
BLECharacteristic::PROPERTY_READ |
BLECharacteristic::PROPERTY_WRITE |
BLECharacteristic::PROPERTY_NOTIFY
);
// Create a BLE Descriptor
pCharacteristic->addDescriptor(new BLE2902());
// Start the service
pService->start();
// Start advertising
BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
pAdvertising->addServiceUUID(SERVICE_UUID);
pAdvertising->setScanResponse(true);
pAdvertising->setMinPreferred(0x06); // functions that help with iPhone connections issue
pAdvertising->setMinPreferred(0x12);
BLEDevice::startAdvertising();
Serial.println("BLE service started, waiting for clients...");
}
void loop() {
if (deviceConnected) {
counter++;
// Cycle through numbers 1-10
if (counter > 10) {
counter = 1;
}
// Convert counter to a string
char counterStr[3];
sprintf(counterStr, "%d", counter);
// Set the value and notify
pCharacteristic->setValue(counterStr);
pCharacteristic->notify();
Serial.print("Sending counter value: ");
Serial.println(counter);
// Wait 1 second before sending the next value
delay(1000);
}
}
Computer code:
import asyncio
from bleak import BleakScanner, BleakClient
SERVICE_UUID = "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
CHARACTERISTIC_UUID = "beb5483e-36e1-4688-b7f5-ea07361b26a8"
ESP32_DEVICE_NAME = "ESP32-Counter"
async def notification_handler(sender, data):
value = int(data.decode())
print(f"Received value: {value}")
async def find_esp32():
print("Scanning for ESP32 device...")
devices = await BleakScanner.discover()
for device in devices:
if [device.name](http://device.name/) == ESP32_DEVICE_NAME:
print(f"Found ESP32 device: {device.name} [{device.address}]")
return device
return None
async def connect_to_esp32():
device = await find_esp32()
if not device:
print(f"Could not find {ESP32_DEVICE_NAME}. Make sure it's powered on and advertising.")
return
try:
async with BleakClient(device) as client:
print(f"Connected to {device.name}")
await client.start_notify(
CHARACTERISTIC_UUID,
notification_handler
)
print("Listening for counter values. Press Ctrl+C to exit.")
while True:
await asyncio.sleep(1)
except Exception as e:
print(f"Error: {e}")
finally:
print("Disconnected from ESP32")
if __name__ == "__main__":
asyncio.run(connect_to_esp32())