* BIG refactor: 'board' and 'radio' objects now defined in 'target.h/.cpp'

* mesh::RTCClock class moved to MeshCore.h

variants/xiao_c3/platformio.ini

@@ -3,6 +3,7 @@ extends = esp32_base
 board = seeed_xiao_esp32c3
 build_flags =
   ${esp32_base.build_flags}
+  -I variants/xiao_c3
   -D LORA_TX_BOOST_PIN=D3
   -D P_LORA_TX_LED=D5
   -D PIN_VBAT_READ=D0
@@ -15,6 +16,8 @@ build_flags =
   -D SX126X_DIO2_AS_RF_SWITCH=true
   -D SX126X_DIO3_TCXO_VOLTAGE=1.8
   -D SX126X_CURRENT_LIMIT=130.0f  ; for best TX power!
+build_src_filter = ${esp32_base.build_src_filter}
+  +<../variants/xiao_c3>
 
 [env:Xiao_C3_Repeater_sx1262]
 extends = Xiao_esp32_C3

variants/xiao_c3/target.cpp

@@ -0,0 +1,47 @@
+#include <Arduino.h>
+#include "target.h"
+
+XiaoC3Board board;
+
+#if defined(P_LORA_SCLK)
+  static SPIClass spi;
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY, spi);
+#else
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY);
+#endif
+
+#ifndef LORA_CR
+  #define LORA_CR      5
+#endif
+
+bool radio_init() {
+#ifdef SX126X_DIO3_TCXO_VOLTAGE
+  float tcxo = SX126X_DIO3_TCXO_VOLTAGE;
+#else
+  float tcxo = 1.6f;
+#endif
+
+#if defined(P_LORA_SCLK)
+  spi.begin(P_LORA_SCLK, P_LORA_MISO, P_LORA_MOSI);
+#endif
+  int status = radio.begin(LORA_FREQ, LORA_BW, LORA_SF, LORA_CR, RADIOLIB_SX126X_SYNC_WORD_PRIVATE, LORA_TX_POWER, 8, tcxo);
+  if (status != RADIOLIB_ERR_NONE) {
+    Serial.print("ERROR: radio init failed: ");
+    Serial.println(status);
+    return false;  // fail
+  }
+  
+  radio.setCRC(1);
+  
+#ifdef SX126X_CURRENT_LIMIT
+  radio.setCurrentLimit(SX126X_CURRENT_LIMIT);
+#endif
+#ifdef SX126X_DIO2_AS_RF_SWITCH
+  radio.setDio2AsRfSwitch(SX126X_DIO2_AS_RF_SWITCH);
+#endif
+#ifdef SX126X_RX_BOOSTED_GAIN
+  radio.setRxBoostedGainMode(SX126X_RX_BOOSTED_GAIN);
+#endif
+
+  return true;  // success
+}

variants/xiao_c3/target.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <helpers/XiaoC3Board.h>
+#include <helpers/CustomSX1262Wrapper.h>
+#include <helpers/CustomSX1268Wrapper.h>
+
+extern XiaoC3Board board;
+extern RADIO_CLASS radio;
+
+bool radio_init();