refactor(rc channels): Use event handler for fail-safe and RC channels

examples/platformio/main.cpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief This is the main development file for CRSF for Arduino.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -29,6 +29,8 @@
 
 CRSFforArduino *crsf = nullptr;
 
+void onReceiveRcChannels(serialReceiverLayer::rcChannels_t *rcChannels);
+
 void setup()
 {
     Serial.begin(115200);
@@ -51,33 +53,51 @@ void setup()
             delay(10);
         }
     }
+
+    crsf->setRcChannelsCallback(onReceiveRcChannels);
 }
 
 void loop()
 {
     crsf->update();
+}
 
-    /* Print RC channels every 100 ms. Do this using the millis() function to avoid blocking the main loop. */
-    static unsigned long lastPrint = 0;
+void onReceiveRcChannels(serialReceiverLayer::rcChannels_t *rcChannels)
+{
+    static unsigned long lastPrint = millis();
     if (millis() - lastPrint >= 100)
     {
         lastPrint = millis();
-        Serial.print("RC Channels <A: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(1)));
-        Serial.print(", E: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(2)));
-        Serial.print(", T: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(3)));
-        Serial.print(", R: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(4)));
-        Serial.print(", Aux1: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(5)));
-        Serial.print(", Aux2: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(6)));
-        Serial.print(", Aux3: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(7)));
-        Serial.print(", Aux4: ");
-        Serial.print(crsf->rcToUs(crsf->getChannel(8)));
-        Serial.println(">");
+
+        static bool initialised = false;
+        static bool lastFailSafe = false;
+        if (rcChannels->failsafe != lastFailSafe || !initialised)
+        {
+            initialised = true;
+            lastFailSafe = rcChannels->failsafe;
+            Serial.print("FailSafe: ");
+            Serial.println(lastFailSafe ? "Active" : "Inactive");
+        }
+
+        if (rcChannels->failsafe == false)
+        {
+            Serial.print("RC Channels <A: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[0]));
+            Serial.print(", E: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[1]));
+            Serial.print(", T: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[2]));
+            Serial.print(", R: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[3]));
+            Serial.print(", Aux1: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[4]));
+            Serial.print(", Aux2: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[5]));
+            Serial.print(", Aux3: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[6]));
+            Serial.print(", Aux4: ");
+            Serial.print(crsf->rcToUs(rcChannels->value[7]));
+            Serial.println(">");
+        }
     }
 }

examples/rc_channels/rc_channels.ino

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief Example of how to read rc channels from a receiver.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -49,6 +49,8 @@ const char *rcChannelNames[] = {
     "Aux11",
     "Aux12"};
 
+void onReceiveRcChannels(serialReceiverLayer::rcChannels_t *rcChannels);
+
 void setup()
 {
     // Initialise the serial port & wait for the port to open.
@@ -76,6 +78,8 @@ void setup()
 
     rcChannelCount = rcChannelCount > crsfProtocol::RC_CHANNEL_COUNT ? crsfProtocol::RC_CHANNEL_COUNT : rcChannelCount;
 
+    crsf->setRcChannelsCallback(onReceiveRcChannels);
+
     // Show the user that the sketch is ready.
     Serial.println("RC Channels Example");
     delay(1000);
@@ -86,43 +90,49 @@ void setup()
 void loop()
 {
     crsf->update();
+}
 
-    /* Print RC channels every 100 ms. */
-    unsigned long thisTime = millis();
-    static unsigned long lastTime = millis();
-
-    /* Compensate for millis() overflow. */
-    if (thisTime < lastTime)
+void onReceiveRcChannels(serialReceiverLayer::rcChannels_t *rcChannels)
+{
+    if (rcChannels->failsafe == false)
     {
-        lastTime = thisTime;
-    }
+        /* Print RC channels every 100 ms. */
+        unsigned long thisTime = millis();
+        static unsigned long lastTime = millis();
 
-    if (thisTime - lastTime >= 100)
-    {
-        lastTime = thisTime;
-#if USE_SERIAL_PLOTTER > 0
-        for (int i = 1; i <= rcChannelCount; i++)
+        /* Compensate for millis() overflow. */
+        if (thisTime < lastTime)
         {
-            Serial.print(i);
-            Serial.print(":");
-            Serial.print(crsf->rcToUs(crsf->getChannel(i)));
-            Serial.print("\t");
+            lastTime = thisTime;
         }
-        Serial.println();
-#else
-        Serial.print("RC Channels <");
-        for (int i = 1; i <= rcChannelCount; i++)
-        {
-            Serial.print(rcChannelNames[i - 1]);
-            Serial.print(": ");
-            Serial.print(crsf->rcToUs(crsf->getChannel(i)));
 
-            if (i < rcChannelCount)
+        if (thisTime - lastTime >= 100)
+        {
+            lastTime = thisTime;
+#if USE_SERIAL_PLOTTER > 0
+            for (int i = 1; i <= rcChannelCount; i++)
             {
-                Serial.print(", ");
+                Serial.print(i);
+                Serial.print(":");
+                Serial.print(crsf->rcToUs(crsf->getChannel(i)));
+                Serial.print("\t");
             }
-        }
-        Serial.println(">");
+            Serial.println();
+#else
+            Serial.print("RC Channels <");
+            for (int i = 1; i <= rcChannelCount; i++)
+            {
+                Serial.print(rcChannelNames[i - 1]);
+                Serial.print(": ");
+                Serial.print(crsf->rcToUs(crsf->getChannel(i)));
+
+                if (i < rcChannelCount)
+                {
+                    Serial.print(", ");
+                }
+            }
+            Serial.println(">");
 #endif
+        }
     }
 }

src/CFA_Config.hpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief This is the configuration file for CRSF for Arduino.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -37,11 +37,19 @@ namespace crsfForArduinoConfig
 Versioning is done using Semantic Versioning 2.0.0.
 See https://semver.org/ for more information. */
 #define CRSFFORARDUINO_VERSION       "1.0.0"
-#define CRSFFORARDUINO_VERSION_DATE  "2024-2-6"
+#define CRSFFORARDUINO_VERSION_DATE  "2024-2-7"
 #define CRSFFORARDUINO_VERSION_MAJOR 1
 #define CRSFFORARDUINO_VERSION_MINOR 0
 #define CRSFFORARDUINO_VERSION_PATCH 0
 
+/* Failsafe Options
+- CRSF_FAILSAFE_LQI_THRESHOLD: The minimum LQI value for the receiver to be considered connected.
+- CRSF_FAILSAFE_RSSI_THRESHOLD: The minimum RSSI value for the receiver to be considered connected.
+  - NB: It is considered good practice to set this value to the same as the RSSI Sensitivity Limit in your Lua script.
+*/
+#define CRSF_FAILSAFE_LQI_THRESHOLD  80
+#define CRSF_FAILSAFE_RSSI_THRESHOLD 105
+
 /* RC Options
 - RC_ENABLED: Enables or disables the RC API.
 - RC_MAX_CHANNELS: The maximum number of RC channels to be received.

src/CRSFforArduino.cpp

@@ -4,7 +4,7 @@
  * @brief This is the Sketch Layer, which is a simplified API for CRSF for Arduino.
  * It is intended to be used by the user in their sketches.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -118,7 +118,7 @@ namespace sketchLayer
      *
      * @return The RC value.
      */
-    uint16_t CRSFforArduino::readRcChannel(uint8_t channel, bool raw)
+    [[deprecated("Use RC channel callback instead")]] uint16_t CRSFforArduino::readRcChannel(uint8_t channel, bool raw)
     {
 #if CRSF_RC_ENABLED > 0
         return _serialReceiver->readRcChannel(channel - 1, raw);
@@ -138,7 +138,7 @@ namespace sketchLayer
      * @param channel The channel to read.
      * @return The RC value.
      */
-    uint16_t CRSFforArduino::getChannel(uint8_t channel)
+    [[deprecated("Use RC channel callback instead")]] uint16_t CRSFforArduino::getChannel(uint8_t channel)
     {
 #if CRSF_RC_ENABLED > 0
         return _serialReceiver->getChannel(channel - 1);
@@ -170,6 +170,16 @@ namespace sketchLayer
 #endif
     }
 
+    void CRSFforArduino::setRcChannelsCallback(void (*callback)(serialReceiverLayer::rcChannels_t *rcChannels))
+    {
+#if CRSF_RC_ENABLED > 0
+        _serialReceiver->setRcChannelsCallback(callback);
+#else
+        // Prevent compiler warnings
+        (void)callback;
+#endif
+    }
+
     void CRSFforArduino::setLinkStatisticsCallback(void (*callback)(serialReceiverLayer::link_statistics_t linkStatistics))
     {
 #if CRSF_LINK_STATISTICS_ENABLED > 0

src/CRSFforArduino.hpp

@@ -4,7 +4,7 @@
  * @brief This is the Sketch Layer, which is a simplified API for CRSF for Arduino.
  * It is intended to be used by the user in their sketches.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -46,6 +46,7 @@ namespace sketchLayer
         uint16_t getChannel(uint8_t channel);
         uint16_t rcToUs(uint16_t rc);
         uint16_t readRcChannel(uint8_t channel, bool raw = false);
+        void setRcChannelsCallback(void (*callback)(serialReceiverLayer::rcChannels_t *rcChannels));
 
         // Link statistics functions.
         void setLinkStatisticsCallback(void (*callback)(serialReceiverLayer::link_statistics_t linkStatistics));

src/SerialReceiver/CRC/CRC.cpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief A generic CRC8 implementation for the CRSF for Arduino library.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *

src/SerialReceiver/CRC/CRC.hpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief A generic CRC8 implementation for the CRSF for Arduino library.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *

src/SerialReceiver/CRSF/CRSF.cpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief This decodes CRSF frames from a serial port.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -163,6 +163,18 @@ namespace serialReceiverLayer
         return false;
     }
 
+    void CRSF::getFailSafe(bool *failSafe)
+    {
+        if (linkStatistics.lqi <= CRSF_FAILSAFE_LQI_THRESHOLD || linkStatistics.rssi >= CRSF_FAILSAFE_RSSI_THRESHOLD)
+        {
+            *failSafe = true;
+        }
+        else
+        {
+            *failSafe = false;
+        }
+    }
+
     void CRSF::getRcChannels(uint16_t *rcChannels)
     {
         if (rcFrameReceived)

src/SerialReceiver/CRSF/CRSF.hpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief This decodes CRSF frames from a serial port.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *
@@ -62,6 +62,7 @@ namespace serialReceiverLayer
         void end();
         void setFrameTime(uint32_t baudRate, uint8_t packetCount = 10);
         bool receiveFrames(uint8_t rxByte);
+        void getFailSafe(bool *failSafe);
         void getRcChannels(uint16_t *rcChannels);
         void getLinkStatistics(link_statistics_t *linkStats);
 

src/SerialReceiver/CRSF/CRSFProtocol.hpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief This file contains enums and structs for the CRSF protocol.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *

src/SerialReceiver/SerialBuffer/SerialBuffer.cpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief A generic serial buffer for the CRSF for Arduino library.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *

src/SerialReceiver/SerialBuffer/SerialBuffer.hpp

@@ -3,7 +3,7 @@
  * @author Cassandra "ZZ Cat" Robinson (nicad.heli.flier@gmail.com)
  * @brief A generic serial buffer for the CRSF for Arduino library.
  * @version 1.0.0
- * @date 2024-2-6
+ * @date 2024-2-7
  *
  * @copyright Copyright (c) 2024, Cassandra "ZZ Cat" Robinson. All rights reserved.
  *