thinknode_m8: initial support

variants/thinknode_m8/ThinkNodeM8Board.cpp

@@ -0,0 +1,38 @@
+#include <Arduino.h>
+#include <Wire.h>
+
+#include "ThinkNodeM8Board.h"
+
+#ifdef THINKNODE_M8
+
+void ThinkNodeM8Board::begin() {
+  NRF52Board::begin();
+
+  Wire.begin();
+
+#ifdef P_LORA_TX_LED
+  pinMode(P_LORA_TX_LED, OUTPUT);
+  digitalWrite(P_LORA_TX_LED, LOW);
+#endif
+
+  pinMode(SX126X_POWER_EN, OUTPUT);
+  digitalWrite(SX126X_POWER_EN, HIGH);
+  delay(10); // give sx1262 some time to power up
+}
+
+uint16_t ThinkNodeM8Board::getBattMilliVolts() {
+  int adcvalue = 0;
+
+  digitalWrite(ADC_EN, HIGH);
+  analogReference(AR_INTERNAL_2_4);
+  analogReadResolution(12);
+  delay(10);
+
+  // ADC range is 0..3000mV and resolution is 12-bit (0..4095)
+  adcvalue = analogRead(PIN_VBAT_READ);
+  // Convert the raw value to compensated mv, taking the resistor-
+  // divider into account (providing the actual LIPO voltage)
+  digitalWrite(ADC_EN, LOW);
+  return (uint16_t)((float)adcvalue * REAL_VBAT_MV_PER_LSB);
+}
+#endif