ESP32c3: Migrate variants to new structure (#7342)

variants/esp32c3/heltec_esp32c3/pins_arduino.h

@@ -0,0 +1,24 @@
+#ifndef Pins_Arduino_h
+#define Pins_Arduino_h
+
+#include <stdint.h>
+
+static const uint8_t TX = 21;
+static const uint8_t RX = 20;
+
+static const uint8_t SDA = 1;
+static const uint8_t SCL = 0;
+
+static const uint8_t SS = 8;
+static const uint8_t MOSI = 7;
+static const uint8_t MISO = 6;
+static const uint8_t SCK = 10;
+
+static const uint8_t A0 = 0;
+static const uint8_t A1 = 1;
+static const uint8_t A2 = 2;
+static const uint8_t A3 = 3;
+static const uint8_t A4 = 4;
+static const uint8_t A5 = 5;
+
+#endif /* Pins_Arduino_h */

variants/esp32c3/heltec_esp32c3/platformio.ini

@@ -0,0 +1,11 @@
+[env:heltec-ht62-esp32c3-sx1262]
+extends = esp32c3_base
+board = esp32-c3-devkitm-1
+build_flags = 
+  ${esp32_base.build_flags}
+  -D HELTEC_HT62
+  -I variants/esp32c3/heltec_esp32c3
+monitor_speed = 115200
+upload_protocol = esptool
+;upload_port = /dev/ttyUSB0
+upload_speed = 921600

variants/esp32c3/heltec_esp32c3/variant.h

@@ -0,0 +1,29 @@
+#define BUTTON_PIN 9
+
+// LED pin on HT-DEV-ESP_V2 and HT-DEV-ESP_V3
+// https://resource.heltec.cn/download/HT-CT62/HT-CT62_Reference_Design.pdf
+// https://resource.heltec.cn/download/HT-DEV-ESP/HT-DEV-ESP_V3_Sch.pdf
+#define LED_PIN 2      // LED
+#define LED_STATE_ON 1 // State when LED is lit
+
+#define HAS_SCREEN 0
+#define HAS_GPS 0
+#undef GPS_RX_PIN
+#undef GPS_TX_PIN
+
+#define USE_SX1262
+#define LORA_SCK 10
+#define LORA_MISO 6
+#define LORA_MOSI 7
+#define LORA_CS 8
+#define LORA_DIO0 RADIOLIB_NC
+#define LORA_RESET 5
+#define LORA_DIO1 3
+#define LORA_DIO2 RADIOLIB_NC
+#define LORA_BUSY 4
+#define SX126X_CS LORA_CS
+#define SX126X_DIO1 LORA_DIO1
+#define SX126X_BUSY LORA_BUSY
+#define SX126X_RESET LORA_RESET
+#define SX126X_DIO2_AS_RF_SWITCH
+#define SX126X_DIO3_TCXO_VOLTAGE 1.8