Add MeshCore relay_radio firmware for Heltec T114

variants/heltec_e290/HeltecE290Board.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <Arduino.h>
+#include <helpers/RefCountedDigitalPin.h>
+#include <helpers/ESP32Board.h>
+#include <driver/rtc_io.h>
+
+class HeltecE290Board : public ESP32Board {
+
+public:
+  RefCountedDigitalPin periph_power;
+
+  HeltecE290Board() : periph_power(PIN_VEXT_EN, PIN_VEXT_EN_ACTIVE) { }
+
+  void begin();
+  void enterDeepSleep(uint32_t secs, int pin_wake_btn = -1);
+  void powerOff() override;
+  uint16_t getBattMilliVolts() override;
+  const char* getManufacturerName() const override ;
+
+};