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libraries/audio-tools/examples/examples-communication/serial/mp3/receive-mp3/receive-mp3.ino

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+
+/**
+ * @file receive-mp3.ino
+ * @brief Example of receiving an mp3 stream over serial and playing it over I2S
+ * using the AudioTools library.
+ * The processing must be synchronized with RTS/CTS flow control to prevent a
+ * buffer overflow and lost data.
+ */
+#include "AudioTools.h"
+#include "AudioTools/AudioCodecs/CodecMP3Helix.h"
+#include "AudioTools/AudioLibs/AudioBoardStream.h"
+
+
+AudioBoardStream i2s(AudioKitEs8388V1);  // final output of decoded stream
+EncodedAudioStream dec(&i2s, new MP3DecoderHelix());  // Decoding stream
+HardwareSerial MP3Serial(1);             // define a Serial for UART1
+StreamCopy copier(dec, MP3Serial);       // copy url to decoder
+// pins
+const int MySerialTX = -1;
+const int MySerialRX = 18;
+const int MySerialRTS = -1;
+const int MySerialCTS = 20;
+
+void setup() {
+  Serial.begin(115200);
+  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);
+
+  // setup serial data source with flow control
+  MP3Serial.begin(115200, SERIAL_8N1);
+  MP3Serial.setPins(MySerialRX, MySerialTX, MySerialCTS, MySerialRTS);
+  MP3Serial.setHwFlowCtrlMode(UART_HW_FLOWCTRL_CTS_RTS);
+ 
+  // setup i2s
+  auto config = i2s.defaultConfig(TX_MODE);
+  i2s.begin(config);
+
+  // setup I2S based on sampling rate provided by decoder
+  dec.begin();
+
+}
+
+void loop() { copier.copy(); }

libraries/audio-tools/examples/examples-communication/serial/mp3/send-mp3/send-mp3.ino

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+
+/**
+ * @file send-mp3.ino
+ * @brief ESP32 Example of sending an mp3 stream over Serial the AudioTools library.
+ * The processing must be synchronized with RTS/CTS flow control to prevent a
+ * buffer overflow and lost data. We get the mp3 from an URLStream.
+ * We used a ESP32 Dev Module for the test.
+ */
+#include <HardwareSerial.h>
+
+#include "AudioTools.h"
+#include "AudioTools/AudioCodecs/CodecMP3Helix.h"
+#include "AudioTools/Communication/AudioHttp.h"
+
+URLStream url("ssid", "password");  // or replace with ICYStream to get metadata
+HardwareSerial MP3Serial(1);             // define a Serial for UART1
+StreamCopy copier(MP3Serial, url);       // copy url to decoder
+// pins
+const int MySerialTX = 17; // TX2
+const int MySerialRX = -1; // not used
+const int MySerialRTS = 4; // GPIO 4
+const int MySerialCTS = -1; // not useed
+
+void setup() {
+  Serial.begin(115200);
+  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);
+
+  // improve performance
+  MP3Serial.setTxBufferSize(1024); // must be called before begin
+
+  // setup serial data sink with flow control
+  MP3Serial.begin(115200, SERIAL_8N1);
+  MP3Serial.setPins(MySerialRX, MySerialTX, MySerialCTS, MySerialRTS);
+  MP3Serial.setHwFlowCtrlMode(UART_HW_FLOWCTRL_CTS_RTS);
+
+  // mp3 radio
+  url.begin("http://stream.srg-ssr.ch/m/rsj/mp3_128", "audio/mp3");
+}
+
+void loop() { copier.copy(); }