initial support for lilygo t impulse plus

variants/lilygo_t_impulse_plus/TImpulsePlusBoard.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <MeshCore.h>
+#include <Arduino.h>
+#include <helpers/NRF52Board.h>
+
+class TImpulsePlusBoard : public NRF52BoardDCDC {
+protected:
+  uint8_t btn_prev_state;
+
+public:
+  TImpulsePlusBoard() : NRF52Board("T-Impulse-Plus OTA") {}
+  void begin();
+
+#if defined(P_LORA_TX_LED)
+  void onBeforeTransmit() override {
+    digitalWrite(P_LORA_TX_LED, HIGH);   // turn TX LED on
+  }
+  void onAfterTransmit() override {
+    digitalWrite(P_LORA_TX_LED, LOW);   // turn TX LED off
+  }
+#endif
+
+  uint16_t getBattMilliVolts() override {
+    // enable battery voltage measurement
+    digitalWrite(BATTERY_MEASUREMENT_CONTROL, HIGH);
+    delay(100);
+
+    analogReadResolution(12);
+    analogReference(AR_INTERNAL);
+    delay(10);
+
+    // read battery voltage
+    int adcvalue = 0;
+    analogReadResolution(12);
+    analogReference(AR_INTERNAL);
+    delay(10);
+    adcvalue = analogRead(BATTERY_ADC_DATA);
+
+    // disable battery voltage measurement
+    digitalWrite(BATTERY_MEASUREMENT_CONTROL, LOW);
+
+    return ((adcvalue * ((3000.0 / 4096.0)))) * 2.0;
+  }
+
+  const char* getManufacturerName() const override {
+    return "LilyGo T-Impulse-Plus";
+  }
+
+  void powerOff() override {
+    sd_power_system_off();
+  }
+};