Reduced number of SPI operations when reading RF packets

crossbow.ino

@@ -277,8 +277,9 @@ void loop(void)
 {
 #ifdef DEVICE_MODE_TX
     if (txDeviceState.readPacket) {
-        if (LoRa.available()) {
-            qspDecodeIncomingFrame(&qsp, LoRa.read(), ppm, &rxDeviceState);
+        int incomingByte = LoRa.read();
+        if (incomingByte > -1) {
+            qspDecodeIncomingFrame(&qsp, incomingByte, ppm, &rxDeviceState);
         } else {
             txDeviceState.rssi = getRadioRssi();
             txDeviceState.snr = getRadioSnr();
@@ -455,9 +456,12 @@ void onReceive(int packetSize)
 #endif
 
 #ifdef DEVICE_MODE_RX
-    while (LoRa.available())
+
+    int incomingByte;
+
+    while (incomingByte = LoRa.read(), incomingByte > -1)
     {
-        qspDecodeIncomingFrame(&qsp, LoRa.read(), ppm, &rxDeviceState);
+        qspDecodeIncomingFrame(&qsp, incomingByte, ppm, &rxDeviceState);
     }
 
     rxDeviceState.rssi = getRadioRssi();

sbus.cpp

@@ -30,7 +30,7 @@ void sbusPreparePacket(uint8_t packet[], int channels[], bool isSignalLoss, bool
      * 173-1811 with middle at 992 S.BUS protocol requires
      */
     for (uint8_t i = 0; i < SBUS_CHANNEL_NUMBER; i++) {
-        output[i] = mapsChannelToSbus(channels[i]);
+        output[i] = mapChannelToSbus(channels[i]);
     }
 
     uint8_t stateByte = 0x00;