imporved sbus input handling on TX module

crossbow/config.h

@@ -13,8 +13,8 @@
  * DEVICE_MODE_TX
  * DEVICE_MODE_RX
  */
-// #define DEVICE_MODE_TX
-#define DEVICE_MODE_RX
+#define DEVICE_MODE_TX
+// #define DEVICE_MODE_RX
 
 // #define FEATURE_TX_OLED
 // #define FORCE_TX_WITHOUT_INPUT

crossbow/crossbow.ino

@@ -327,6 +327,19 @@ void loop(void)
     uint32_t currentMillis = millis();
 
     /*
+     * If we are not receiving SBUS frames from radio, try to restart serial
+     */
+#ifdef DEVICE_MODE_TX
+
+    static uint32_t serialRestartMillis = 0;
+
+    if (!txInput.isReceiving() && serialRestartMillis + 100 < currentMillis) {
+        txInput.restart();
+        serialRestartMillis = currentMillis;
+    }
+#endif
+
+    /*
      * This routine handles resync of TX/RX while hoppping frequencies
      */
 #ifdef DEVICE_MODE_RX

crossbow/sbus.cpp

@@ -13,7 +13,7 @@
 #define SBUS_STATE_FAILSAFE 0x08
 #define SBUS_STATE_SIGNALLOSS 0x04
 
-#define SBUS_IS_RECEIVING_THRESHOLD 250 //If there is no SBUS input for 250ms, assume connection is broken
+#define SBUS_IS_RECEIVING_THRESHOLD 125 //If there is no SBUS input for 125ms, assume connection is broken
 
 /*
 Precomputed mapping from 990-2010 to 173:1811
@@ -96,6 +96,12 @@ void SbusInput::start(void)
     _serial.begin(100000, SERIAL_8N2);
 }
 
+void SbusInput::restart(void)
+{   
+    _serial.end();
+    start();
+}
+
 void SbusInput::sbusRead() {
     static byte buffer[25];
 	static byte buffer_index = 0;

crossbow/sbus.h

@@ -11,6 +11,7 @@ class SbusInput : public TxInput
   public:
   	SbusInput(HardwareSerial &serial);
     void start(void);
+    void restart(void);
     void loop(void);
     bool isReceiving(void);
   private: