Added ESP32 BLE serial driver

diff --git a/BLESerial.cpp b/BLESerial.cpp
new file mode 100644 (file)
index 0000000..a0bf0ef
--- /dev/null
+++ b/BLESerial.cpp
@@ -0,0 +1,122 @@
+#include "BLESerial.h"
+
+uint32_t bt_passkey_callback();
+void bt_passkey_notify_callback(uint32_t passkey);
+bool bt_security_request_callback();
+void bt_authentication_complete_callback(esp_ble_auth_cmpl_t auth_result);
+bool bt_confirm_pin_callback(uint32_t pin);
+void bt_connect_callback(uint16_t conn_handle);
+void bt_disconnect_callback(uint16_t conn_handle, uint8_t reason);
+
+uint32_t BLESerial::onPassKeyRequest() { return bt_passkey_callback(); }
+void BLESerial::onPassKeyNotify(uint32_t passkey) { bt_passkey_notify_callback(passkey); }
+bool BLESerial::onSecurityRequest() { return bt_security_request_callback(); }
+void BLESerial::onAuthenticationComplete(esp_ble_auth_cmpl_t auth_result) { bt_authentication_complete_callback(auth_result); }
+void BLESerial::onConnect(BLEServer *server) { bt_connect_callback(0); }
+void BLESerial::onDisconnect(BLEServer *server) { bt_disconnect_callback(0, 0); ble_server->startAdvertising(); }
+bool BLESerial::onConfirmPIN(uint32_t pin) { return false; };
+bool BLESerial::connected() { return ble_server->getConnectedCount() > 0; }
+
+int BLESerial::read() {
+  int result = this->rx_buffer.pop();
+  if (result == '\n') { this->numAvailableLines--; }
+  return result;
+}
+
+size_t BLESerial::readBytes(uint8_t *buffer, size_t bufferSize) {
+  int i = 0;
+  while (i < bufferSize && available()) { buffer[i] = (uint8_t)this->rx_buffer.pop(); i++; }
+  return i;
+}
+
+int BLESerial::peek() {
+  if (this->rx_buffer.getLength() == 0) return -1;
+  return this->rx_buffer.get(0);
+}
+
+int BLESerial::available() { return this->rx_buffer.getLength(); }
+
+size_t BLESerial::print(const char *str) {
+  if (ble_server->getConnectedCount() <= 0) return 0;
+  size_t written = 0; for (size_t i = 0; str[i] != '\0'; i++)  { written += this->write(str[i]); }
+  flush();
+
+  return written;
+}
+
+size_t BLESerial::write(const uint8_t *buffer, size_t bufferSize) {
+  if (ble_server->getConnectedCount() <= 0) { return 0; } else {
+    size_t written = 0; for (int i = 0; i < bufferSize; i++) { written += this->write(buffer[i]); }
+    flush();
+
+    return written;
+  }
+}
+
+size_t BLESerial::write(uint8_t byte) {
+  if (ble_server->getConnectedCount() <= 0) { return 0; } else {
+    this->transmitBuffer[this->transmitBufferLength] = byte;
+    this->transmitBufferLength++;
+    if (this->transmitBufferLength == maxTransferSize) { flush(); }
+    return 1;
+  }
+}
+
+void BLESerial::flush() {
+  if (this->transmitBufferLength > 0) {
+    TxCharacteristic->setValue(this->transmitBuffer, this->transmitBufferLength);
+    this->transmitBufferLength = 0;
+    this->lastFlushTime = millis();
+    TxCharacteristic->notify(true);
+  }
+}
+
+void BLESerial::begin(const char *name) {
+  ConnectedDeviceCount = 0;
+  BLEDevice::init(name);
+
+  esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_DEFAULT, ESP_PWR_LVL_P9); 
+  esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_ADV, ESP_PWR_LVL_P9);
+  esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_SCAN ,ESP_PWR_LVL_P9);
+
+  ble_server = BLEDevice::createServer();
+  ble_server->setCallbacks(this);
+  BLEDevice::setSecurityCallbacks(this);
+
+  SetupSerialService();
+
+  ble_adv = BLEDevice::getAdvertising();
+  ble_adv->addServiceUUID(BLE_SERIAL_SERVICE_UUID);
+  ble_adv->setMinPreferred(0x20);
+  ble_adv->setMaxPreferred(0x40);
+  ble_adv->setScanResponse(true);
+  ble_adv->start();
+}
+
+void BLESerial::end() { BLEDevice::deinit(); }
+
+void BLESerial::onWrite(BLECharacteristic *characteristic) {
+  if (characteristic->getUUID().toString() == BLE_RX_UUID) {
+    auto value = characteristic->getValue();
+    for (int i = 0; i < value.length(); i++) { rx_buffer.push(value[i]); }
+  }
+}
+
+void BLESerial::SetupSerialService() {
+  SerialService = ble_server->createService(BLE_SERIAL_SERVICE_UUID);
+
+  RxCharacteristic = SerialService->createCharacteristic(BLE_RX_UUID, BLECharacteristic::PROPERTY_WRITE);
+  RxCharacteristic->setAccessPermissions(ESP_GATT_PERM_WRITE_ENC_MITM);
+  RxCharacteristic->addDescriptor(new BLE2902());
+  RxCharacteristic->setWriteProperty(true);
+  RxCharacteristic->setCallbacks(this);
+
+  TxCharacteristic = SerialService->createCharacteristic(BLE_TX_UUID, BLECharacteristic::PROPERTY_NOTIFY);
+  TxCharacteristic->setAccessPermissions(ESP_GATT_PERM_READ_ENC_MITM);
+  TxCharacteristic->addDescriptor(new BLE2902());
+  TxCharacteristic->setReadProperty(true);
+
+  SerialService->start();
+}
+
+BLESerial::BLESerial() { }

diff --git a/BLESerial.h b/BLESerial.h
new file mode 100644 (file)
index 0000000..d1cae4d
--- /dev/null
+++ b/BLESerial.h
@@ -0,0 +1,111 @@
+#pragma once
+#include <Arduino.h>
+
+#include <BLEDevice.h>
+#include <BLEUtils.h>
+#include <BLEServer.h>
+#include <BLE2902.h>
+
+template <size_t n>
+class BLEFIFO {
+private:
+       uint8_t buffer[n];
+       int head = 0;
+       int tail = 0;
+
+public:
+       void push(uint8_t value) {
+               buffer[head] = value;
+               head = (head + 1) % n;
+               if (head == tail) { tail = (tail + 1) % n; }
+       }
+
+       int pop() {
+               if (head == tail) {
+                       return -1;
+               } else {
+                       uint8_t value = buffer[tail];
+                       tail = (tail + 1) % n;
+                       return value;
+               }
+       }
+
+       void clear() { head = 0; tail = 0; }
+
+       int get(size_t index) {
+               if (index >= this->getLength()) {
+                       return -1;
+               } else {
+                       return buffer[(tail + index) % n];
+               }
+       }
+
+       size_t getLength() {
+               if (head >= tail) {
+                       return head - tail;
+               } else {
+                       return n - tail + head;
+               }
+       }
+};
+
+#define RX_BUFFER_SIZE 6144
+#define BLE_BUFFER_SIZE 512 // Must fit in max GATT attribute length
+#define MIN_MTU 50
+
+class BLESerial : public BLECharacteristicCallbacks, public BLEServerCallbacks, public BLESecurityCallbacks, public Stream {
+public:
+  BLESerial();
+
+  void begin(const char *name);
+  void end();
+  void onWrite(BLECharacteristic *characteristic);
+  int available();
+  int peek();
+  int read();
+  size_t readBytes(uint8_t *buffer, size_t bufferSize);
+  size_t write(uint8_t byte);
+  size_t write(const uint8_t *buffer, size_t bufferSize);
+  size_t print(const char *value);
+  void flush();
+  void onConnect(BLEServer *server);
+  void onDisconnect(BLEServer *server);
+
+  uint32_t onPassKeyRequest();
+  void onPassKeyNotify(uint32_t passkey);
+  bool onSecurityRequest();
+  void onAuthenticationComplete(esp_ble_auth_cmpl_t);
+  bool onConfirmPIN(uint32_t pin);
+
+  bool connected();
+
+  BLEServer *ble_server;
+  BLEAdvertising *ble_adv;
+  BLEService *SerialService;
+  BLECharacteristic *TxCharacteristic;
+  BLECharacteristic *RxCharacteristic;
+  size_t transmitBufferLength;
+  unsigned long long lastFlushTime;
+
+private:
+  BLESerial(BLESerial const &other) = delete;
+  void operator=(BLESerial const &other) = delete;
+
+  BLEFIFO<RX_BUFFER_SIZE> rx_buffer;
+  size_t numAvailableLines;
+  uint8_t transmitBuffer[BLE_BUFFER_SIZE];
+
+  int ConnectedDeviceCount;
+  void SetupSerialService();
+
+  uint16_t peerMTU;
+  uint16_t maxTransferSize = BLE_BUFFER_SIZE;
+
+  bool checkMTU();
+
+  const char *BLE_SERIAL_SERVICE_UUID = "6e400001-b5a3-f393-e0a9-e50e24dcca9e";
+  const char *BLE_RX_UUID = "6e400002-b5a3-f393-e0a9-e50e24dcca9e";
+  const char *BLE_TX_UUID = "6e400003-b5a3-f393-e0a9-e50e24dcca9e";
+
+  bool started = false;
+};