Added bridge for RAK 3401

variants/rak3401/platformio.ini

@@ -50,6 +50,17 @@ build_src_filter = ${rak3401.build_src_filter}
   +<helpers/ui/SSD1306Display.cpp>
   +<../examples/simple_repeater>
 
+[env:RAK_3401_repeater_bridge_rs232_serial1]
+extends = env:RAK_3401_repeater
+build_flags =
+  ${env:RAK_3401_repeater.build_flags}
+  -D ADVERT_NAME='"RAK3401 1W RS232 Bridge"'
+  -D WITH_RS232_BRIDGE=Serial1
+  -D WITH_RS232_BRIDGE_RX=PIN_SERIAL1_RX
+  -D WITH_RS232_BRIDGE_TX=PIN_SERIAL1_TX
+build_src_filter = ${env:RAK_3401_repeater.build_src_filter}
+  +<helpers/bridges/RS232Bridge.cpp>
+
 [env:RAK_3401_room_server]
 extends = rak3401
 build_flags =