drivers/sx126x: add optional CONFIG_SX126X_DEFAULT_SYNC_WORD

Author: fabian18

drivers/include/sx126x.h

@@ -33,6 +33,22 @@
 extern "C" {
 #endif
 
+#if defined(DOXYGEN)
+/**
+ * @brief   Configure the LoRa sync word
+ *
+ * The sync word for sx126x is 16 bits long.
+ * Private networks should use 0x1424.
+ * Public networks should use 0x3444.
+ * Using the driver API you only configure 2 nibbles Y and Z to form a sync word 0xY4Z4.
+ * The default chip value is 0x12 (0x1424).
+ *
+ * See https://blog.classycode.com/lora-sync-word-compatibility-between-sx127x-and-sx126x-460324d1787a
+ * for more information and a comparison with sx127x.
+ */
+#  define CONFIG_SX126X_DEFAULT_SYNC_WORD       0x12
+#endif
+
 /**
  * * @note Forward declaration of the SX126x device descriptor
  */

drivers/sx126x/sx126x.c

@@ -291,6 +291,9 @@ static void sx126x_init_default_config(sx126x_t *dev)
     sx126x_set_pkt_type(dev, SX126X_PKT_TYPE_LORA);
     sx126x_set_channel(dev, CONFIG_SX126X_CHANNEL_DEFAULT);
     sx126x_set_tx_power(dev,  CONFIG_SX126X_TX_POWER_DEFAULT, CONFIG_SX126X_RAMP_TIME_DEFAULT);
+#ifdef CONFIG_SX126X_DEFAULT_SYNC_WORD
+    sx126x_set_lora_sync_word(dev, CONFIG_SX126X_DEFAULT_SYNC_WORD);
+#endif
 
     dev->mod_params.bw = (sx126x_lora_bw_t)(CONFIG_LORA_BW_DEFAULT + SX126X_LORA_BW_125);
     dev->mod_params.sf = (sx126x_lora_sf_t)CONFIG_LORA_SF_DEFAULT;