Initial configuration.h -> variants refactor (#1104)

* Initial configuration to variants refactor

variants/heltec_v1/variant.h

@@ -0,0 +1,29 @@
+// the default ESP32 Pin of 15 is the Oled SCL, set to 36 and 37 and works fine.
+// Tested on Neo6m module.
+#undef GPS_RX_PIN
+#undef GPS_TX_PIN
+#define GPS_RX_PIN 36
+#define GPS_TX_PIN 37
+
+#ifndef USE_JTAG  // gpio15 is TDO for JTAG, so no I2C on this board while doing jtag
+#define I2C_SDA 4 // I2C pins for this board
+#define I2C_SCL 15
+#endif
+
+#define RESET_OLED 16 // If defined, this pin will be used to reset the display controller
+
+#define LED_PIN 25     // If defined we will blink this LED
+#define BUTTON_PIN 0   // If defined, this will be used for user button presses
+
+#define USE_RF95
+#define LORA_DIO0 26 // a No connect on the SX1262 module
+#ifndef USE_JTAG
+#define LORA_RESET 14
+#endif
+#define LORA_DIO1 33 // Not really used
+#define LORA_DIO2 32 // Not really used
+
+// ratio of voltage divider = 3.20 (R1=100k, R2=220k)
+#define ADC_MULTIPLIER 3.2
+
+#define BATTERY_PIN 13 // A battery voltage measurement pin, voltage divider connected here to measure battery voltage