Added support for LilyGo T-Echo

src/helpers/nrf52/TechoBoard.cpp

@@ -0,0 +1,80 @@
+#include <Arduino.h>
+#include "TechoBoard.h"
+
+#include <bluefruit.h>
+#include <Wire.h>
+
+static BLEDfu bledfu;
+
+static void connect_callback(uint16_t conn_handle)
+{
+  (void)conn_handle;
+  MESH_DEBUG_PRINTLN("BLE client connected");
+}
+
+static void disconnect_callback(uint16_t conn_handle, uint8_t reason)
+{
+  (void)conn_handle;
+  (void)reason;
+
+  MESH_DEBUG_PRINTLN("BLE client disconnected");
+}
+
+void TechoBoard::begin() {
+  // for future use, sub-classes SHOULD call this from their begin()
+  startup_reason = BD_STARTUP_NORMAL;
+
+  pinMode(PIN_VBAT_READ, INPUT);
+
+#if defined(PIN_BOARD_SDA) && defined(PIN_BOARD_SCL)
+  Wire.begin(PIN_BOARD_SDA, PIN_BOARD_SCL);
+#else
+  Wire.begin();
+#endif
+
+  pinMode(SX126X_POWER_EN, OUTPUT);
+  digitalWrite(SX126X_POWER_EN, HIGH);
+  delay(10);   // give sx1262 some time to power up
+}
+
+bool TechoBoard::startOTAUpdate() {
+  // Config the peripheral connection with maximum bandwidth
+  // more SRAM required by SoftDevice
+  // Note: All config***() function must be called before begin()
+  Bluefruit.configPrphBandwidth(BANDWIDTH_MAX);
+  Bluefruit.configPrphConn(92, BLE_GAP_EVENT_LENGTH_MIN, 16, 16);
+
+  Bluefruit.begin(1, 0);
+  // Set max power. Accepted values are: -40, -30, -20, -16, -12, -8, -4, 0, 4
+  Bluefruit.setTxPower(4);
+  // Set the BLE device name
+  Bluefruit.setName("TECHO_OTA");
+
+  Bluefruit.Periph.setConnectCallback(connect_callback);
+  Bluefruit.Periph.setDisconnectCallback(disconnect_callback);
+
+  // To be consistent OTA DFU should be added first if it exists
+  bledfu.begin();
+
+  // Set up and start advertising
+  // Advertising packet
+  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
+  Bluefruit.Advertising.addTxPower();
+  Bluefruit.Advertising.addName();
+
+  /* Start Advertising
+    - Enable auto advertising if disconnected
+    - Interval:  fast mode = 20 ms, slow mode = 152.5 ms
+    - Timeout for fast mode is 30 seconds
+    - Start(timeout) with timeout = 0 will advertise forever (until connected)
+
+    For recommended advertising interval
+    https://developer.apple.com/library/content/qa/qa1931/_index.html
+  */
+  Bluefruit.Advertising.restartOnDisconnect(true);
+  Bluefruit.Advertising.setInterval(32, 244); // in unit of 0.625 ms
+  Bluefruit.Advertising.setFastTimeout(30);   // number of seconds in fast mode
+  Bluefruit.Advertising.start(0);             // 0 = Don't stop advertising after n seconds
+
+  return true;
+}

src/helpers/nrf52/TechoBoard.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <MeshCore.h>
+#include <Arduino.h>
+
+// LoRa radio module pins for LilyGo T-Echo
+#define  P_LORA_DIO_1     20
+#define  P_LORA_NSS       24
+#define  P_LORA_RESET     25
+#define  P_LORA_BUSY      17
+#define  P_LORA_SCLK      19
+#define  P_LORA_MISO      23
+#define  P_LORA_MOSI      22
+#define  SX126X_POWER_EN  37
+
+#define SX126X_DIO2_AS_RF_SWITCH  true
+#define SX126X_DIO3_TCXO_VOLTAGE   1.8
+
+// built-ins
+#define  PIN_VBAT_READ    4
+#define  ADC_MULTIPLIER   (2.0)
+
+class TechoBoard : public mesh::MainBoard {
+protected:
+  uint8_t startup_reason;
+
+public:
+  void begin();
+  uint8_t getStartupReason() const override { return startup_reason; }
+
+  #define BATTERY_SAMPLES 8
+
+  uint16_t getBattMilliVolts() override {
+    analogReadResolution(12);
+    uint32_t raw = 0;
+    for (int i = 0; i < BATTERY_SAMPLES; i++) {
+      raw += analogRead(PIN_VBAT_READ);
+    }
+    raw = raw / BATTERY_SAMPLES;
+
+    return (ADC_MULTIPLIER * raw) / 4096;
+  }
+
+  const char* getManufacturerName() const override {
+    return "LilyGo T-Echo";
+  }
+
+  void reboot() override {
+    NVIC_SystemReset();
+  }
+
+  bool startOTAUpdate() override;
+};