Florian
42be3fe0f2
with the last version of ESP32 arduino env it is not possible to compile on ESP32, we get "missing gatt_api.h" ERROR. So as to avoid that we need to use the last version of the nkolban library for BLE 0.4.16
105 lines
3.3 KiB
Arduino
105 lines
3.3 KiB
Arduino
/*
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Video: https://www.youtube.com/watch?v=oCMOYS71NIU
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Based on Neil Kolban example for IDF: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLE%20Tests/SampleNotify.cpp
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Ported to Arduino ESP32 by Evandro Copercini
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Create a BLE server that, once we receive a connection, will send periodic notifications.
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The service advertises itself as: 4fafc201-1fb5-459e-8fcc-c5c9c331914b
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And has a characteristic of: beb5483e-36e1-4688-b7f5-ea07361b26a8
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The design of creating the BLE server is:
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1. Create a BLE Server
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2. Create a BLE Service
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3. Create a BLE Characteristic on the Service
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4. Create a BLE Descriptor on the characteristic
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5. Start the service.
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6. Start advertising.
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A connect hander associated with the server starts a background task that performs notification
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every couple of seconds.
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*/
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#include <BLEDevice.h>
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#include <BLEServer.h>
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#include <BLEUtils.h>
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#include <BLE2902.h>
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BLEServer* pServer = NULL;
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BLECharacteristic* pCharacteristic = NULL;
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bool deviceConnected = false;
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bool oldDeviceConnected = false;
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uint8_t value = 0;
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// See the following for generating UUIDs:
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// https://www.uuidgenerator.net/
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#define SERVICE_UUID "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
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#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"
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class MyServerCallbacks: public BLEServerCallbacks {
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void onConnect(BLEServer* pServer) {
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deviceConnected = true;
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};
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void onDisconnect(BLEServer* pServer) {
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deviceConnected = false;
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}
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};
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void setup() {
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Serial.begin(115200);
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// Create the BLE Device
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BLEDevice::init("MyESP32");
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// Create the BLE Server
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pServer = BLEDevice::createServer();
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pServer->setCallbacks(new MyServerCallbacks());
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// Create the BLE Service
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BLEService *pService = pServer->createService(SERVICE_UUID);
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// Create a BLE Characteristic
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pCharacteristic = pService->createCharacteristic(
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CHARACTERISTIC_UUID,
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BLECharacteristic::PROPERTY_READ |
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BLECharacteristic::PROPERTY_WRITE |
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BLECharacteristic::PROPERTY_NOTIFY |
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BLECharacteristic::PROPERTY_INDICATE
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);
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// https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.descriptor.gatt.client_characteristic_configuration.xml
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// Create a BLE Descriptor
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pCharacteristic->addDescriptor(new BLE2902());
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// Start the service
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pService->start();
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// Start advertising
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pServer->getAdvertising()->start();
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Serial.println("Waiting a client connection to notify...");
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}
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void loop() {
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// notify changed value
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if (deviceConnected) {
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pCharacteristic->setValue(&value, 1);
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pCharacteristic->notify();
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value++;
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delay(10); // bluetooth stack will go into congestion, if too many packets are sent
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}
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// disconnecting
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if (!deviceConnected && oldDeviceConnected) {
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delay(500); // give the bluetooth stack the chance to get things ready
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pServer->startAdvertising(); // restart advertising
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Serial.println("start advertising");
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oldDeviceConnected = deviceConnected;
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}
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// connecting
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if (deviceConnected && !oldDeviceConnected) {
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// do stuff here on connecting
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oldDeviceConnected = deviceConnected;
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}
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} |