codec2 Audio Support for SX1280 (untested)

src/modules/esp32/AudioModule.h

@@ -0,0 +1,68 @@
+#pragma once
+
+#include "SinglePortModule.h"
+#include "concurrency/OSThread.h"
+#include "configuration.h"
+#include "NodeDB.h"
+#include <Arduino.h>
+#include <driver/adc.h>
+#include <functional>
+#if defined(ARCH_ESP32) && defined(USE_SX1280)
+#include <codec2.h>
+#include <ButterworthFilter.h>
+#include <FastAudioFIFO.h>
+#else
+typedef int FastAudioFIFO;
+#endif
+
+#define ADC_BUFFER_SIZE 320 // 40ms of voice in 8KHz sampling frequency
+#define ENCODE_FRAME_SIZE 40 // 5 codec2 frames of 8 bytes each
+
+class AudioModule : public SinglePortModule, private concurrency::OSThread
+{
+  bool firstTime = 1;
+  hw_timer_t* adcTimer = NULL;
+  uint16_t adc_buffer[ADC_BUFFER_SIZE];
+  int16_t speech[ADC_BUFFER_SIZE];
+  int16_t output_buffer[ADC_BUFFER_SIZE];
+  unsigned char rx_encode_frame[ENCODE_FRAME_SIZE];
+  unsigned char tx_encode_frame[ENCODE_FRAME_SIZE];
+  int tx_encode_frame_index = 0;
+  FastAudioFIFO audio_fifo;
+  uint16_t adc_buffer_index = 0;
+  adc1_channel_t mic_chan = (adc1_channel_t)0;
+  struct CODEC2* codec2_state;
+
+  enum State
+  {
+	  standby, rx, tx 
+  };
+  volatile State state = State::tx;
+
+  public:
+    AudioModule();
+
+    /**
+     * Send our payload into the mesh
+     */
+    void sendPayload(NodeNum dest = NODENUM_BROADCAST, bool wantReplies = false);
+
+  protected:
+    virtual int32_t runOnce() override;
+
+    static void handleInterrupt();
+
+    void onTimer();
+
+    void run_codec2();
+
+    virtual MeshPacket *allocReply() override;
+
+    /** Called to handle a particular incoming message
+     * @return ProcessMessage::STOP if you've guaranteed you've handled this message and no other handlers should be considered for it
+     */
+    virtual ProcessMessage handleReceived(const MeshPacket &mp) override;
+};
+
+extern AudioModule *audioModule;
+