Initial commit: Simple Sensor firmware for Heltec T114 with BME280

- MeshCore-based Simple Sensor firmware
- Heltec T114 without display
- BME280 sensor support (temp/humidity/pressure)
- Radio: 868.856018 MHz, SF7, BW62.5 kHz, CR4/7
- 2-byte path hash
- PlatformIO project

variants/thinknode_m2/ThinknodeM2Board.cpp

@@ -0,0 +1,40 @@
+#include "ThinknodeM2Board.h"
+
+
+
+void ThinknodeM2Board::begin() {
+    pinMode(PIN_VEXT_EN, OUTPUT); 
+    digitalWrite(PIN_VEXT_EN, !PIN_VEXT_EN_ACTIVE); // force power cycle
+    delay(20); // allow power rail to discharge
+    digitalWrite(PIN_VEXT_EN, PIN_VEXT_EN_ACTIVE); // turn backlight back on
+    delay(120); // give display time to bias on cold boot
+    ESP32Board::begin();
+    pinMode(PIN_STATUS_LED, OUTPUT); // init power led
+  }
+
+  void ThinknodeM2Board::enterDeepSleep(uint32_t secs, int pin_wake_btn) {
+    esp_deep_sleep_start();
+  }
+
+  void ThinknodeM2Board::powerOff()  {
+    enterDeepSleep(0);
+  }
+
+ uint16_t ThinknodeM2Board::getBattMilliVolts() {
+    analogReadResolution(12);
+    analogSetPinAttenuation(PIN_VBAT_READ, ADC_11db);
+
+    uint32_t mv = 0;
+      for (int i = 0; i < 8; ++i) {
+        mv += analogReadMilliVolts(PIN_VBAT_READ);
+        delayMicroseconds(200);
+      }
+    mv /= 8;
+
+    analogReadResolution(10);  
+    return static_cast<uint16_t>(mv * ADC_MULTIPLIER );
+}
+
+  const char* ThinknodeM2Board::getManufacturerName() const {
+    return "Elecrow ThinkNode M2";
+  }