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Diffstat (limited to 'examples/BLE_server_multiconnect/BLE_server_multiconnect.ino')
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1 files changed, 111 insertions, 0 deletions
diff --git a/examples/BLE_server_multiconnect/BLE_server_multiconnect.ino b/examples/BLE_server_multiconnect/BLE_server_multiconnect.ino new file mode 100644 index 0000000..a8bdd63 --- /dev/null +++ b/examples/BLE_server_multiconnect/BLE_server_multiconnect.ino @@ -0,0 +1,111 @@ +/* + 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 + updated by chegewara + + Create a BLE server that, once we receive a connection, will send periodic notifications. + The service advertises itself as: 4fafc201-1fb5-459e-8fcc-c5c9c331914b + And has a characteristic of: beb5483e-36e1-4688-b7f5-ea07361b26a8 + + 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. + + A connect hander associated with the server starts a background task that performs notification + every couple of seconds. +*/ +#include <BLEDevice.h> +#include <BLEServer.h> +#include <BLEUtils.h> +#include <BLE2902.h> + +BLEServer* pServer = NULL; +BLECharacteristic* pCharacteristic = NULL; +bool deviceConnected = false; +bool oldDeviceConnected = false; +uint32_t value = 0; + +// See the following for generating UUIDs: +// https://www.uuidgenerator.net/ + +#define SERVICE_UUID "4fafc201-1fb5-459e-8fcc-c5c9c331914b" +#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8" + + +class MyServerCallbacks: public BLEServerCallbacks { + void onConnect(BLEServer* pServer) { + deviceConnected = true; + BLEAdvertising::startAdvertising(); + }; + + void onDisconnect(BLEServer* pServer) { + deviceConnected = false; + } +}; + + + +void setup() { + Serial.begin(115200); + + // Create the BLE Device + BLEDevice::init("ESP32"); + + // 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 | + BLECharacteristic::PROPERTY_INDICATE + ); + + // https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.descriptor.gatt.client_characteristic_configuration.xml + // 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(false); + pAdvertising->setMinPreferred(0x0); // set value to 0x00 to not advertise this parameter + BLEDevice::startAdvertising(); + Serial.println("Waiting a client connection to notify..."); +} + +void loop() { + // notify changed value + if (deviceConnected) { + pCharacteristic->setValue(&value, 1); + pCharacteristic->notify(); + value++; + delay(3); // bluetooth stack will go into congestion, if too many packets are sent, in 6 hours test i was able to go as low as 3ms + } + // 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; + } +}
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