Always send an M17 EOT frame as the last frame before terminating baseband output

meson.build

@@ -22,8 +22,7 @@ def += {'FONT_UBUNTU_REGULAR': ''}
 ## Firmware configuration parameters
 ##
 
-# Send an M17 EOT frame at the end of transmission
-#def += {'M17_ENABLE_EOT' : ''}
+#def += {}
 
 
 ##

openrtx/include/protocols/M17/M17FrameEncoder.hpp

@@ -84,6 +84,14 @@ public:
      */
     uint16_t encodeStreamFrame(const payload_t& payload, frame_t& output,
                                const bool isLast = false);
+
+    /**
+     * Encode an End Of Transmission marker frame.
+     *
+     * @param output: destination buffer for the encoded data.
+     */
+    void encodeEotFrame(frame_t& output);
+
 private:
 
     M17ConvolutionalEncoder  encoder;           ///< Convolutional encoder.

openrtx/include/protocols/M17/M17Modulator.hpp

@@ -80,8 +80,6 @@ public:
 
     /**
      * Terminate baseband transmission.
-     * If the macro M17_ENABLE_EOT is defined an EOT frame is sent before
-     * terminating the transmission.
      */
     void stop();
 

openrtx/src/protocols/M17/M17FrameEncoder.cpp

@@ -116,3 +116,12 @@ uint16_t M17FrameEncoder::encodeStreamFrame(const payload_t& payload,
 
     return streamFrame.getFrameNumber();
 }
+
+void M17::M17FrameEncoder::encodeEotFrame(M17::frame_t& output)
+{
+    for(size_t i = 0; i < output.size(); i += 2)
+    {
+        output[i]     = 0x55;
+        output[i + 1] = 0x5D;
+    }
+}

openrtx/src/protocols/M17/M17Modulator.cpp

@@ -130,27 +130,6 @@ void M17Modulator::stop()
     if(txRunning == false)
         return;
 
-    #ifdef M17_ENABLE_EOT
-    frame_t eotFrame;
-    // Fill EOT frame with 0x55, 0x5D as per M17 spec.
-    for(size_t i = 0; i < eotFrame.size(); i += 2)
-    {
-        eotFrame[i]     = 0x55;
-        eotFrame[i + 1] = 0x5D;
-    }
-
-    // Convert to symbols
-    auto it = symbols.begin();
-    for(size_t i = 0; i < eotFrame.size(); i++)
-    {
-        auto sym = byteToSymbols(eotFrame[i]);
-        it       = std::copy(sym.begin(), sym.end(), it);
-    }
-
-    symbolsToBaseband();
-    sendBaseband();
-    #endif
-
     outputStream_stop(outStream);
     outputStream_sync(outStream, false);
     txRunning  = false;

openrtx/src/rtx/OpMode_M17.cpp

@@ -242,5 +242,9 @@ void OpMode_M17::txState(rtxStatus_t *const status)
     modulator.send(m17Frame);
 
     if(lastFrame)
+    {
+        encoder.encodeEotFrame(m17Frame);
+        modulator.send(m17Frame);
         modulator.stop();
+    }
 }