168 lines
6.8 KiB
C++
168 lines
6.8 KiB
C++
#include "Arduino.h"
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/*
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I2S Bluetooth Transmitter
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Can be connected to an I2S Master.Sampling rate must be 48KHz
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Include PSchatzmann /ESP32-A2DP https://github.com/pschatzmann/ESP32-A2DP.git
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*/
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#include "Arduino.h"
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#include "esp_bt.h"
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#include "BluetoothA2DPCommon.h"
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#include "BluetoothA2DPSource.h"
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#include <driver/i2s_std.h>
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#include "AudioResampler.hpp"
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#define RX_I2S_DIN 25 // connect with I2S Master (signal dout)
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#define RX_I2S_BCLK 27 // connect with I2S Master (bit clock)
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#define RX_I2S_LRC 26 // connect with I2S Master (word select)
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#define MEASUREMENT_INTERVAL_MS 100 // Messintervall in ms
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#define TOLERANCE_PERCENT 5 // Toleranz für Schwankungen in %
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static volatile uint32_t lrck_count = 0;
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static uint32_t current_samplerate = 0;
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BluetoothA2DPSource a2dp_source;
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AudioResampleBuffer resampler;
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char BT_SINK_NAME[] = " Pebble V3\r\n"; // set your sink devicename here
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//char BT_SINK_NAME[] = "Manhattan-165327";
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i2s_chan_handle_t i2s_rx_handle = {};
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i2s_chan_config_t i2s_chan_cfg = {}; // stores I2S channel values
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i2s_std_config_t i2s_std_cfg = {}; // stores I2S driver values
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const i2s_port_t i2s_num = I2S_NUM_0;
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//--------------------------------Recognise Host Samplerate-------------------------------------------------------------------------------------
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// Interrupt-Handler for LRCK-Pulse
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void IRAM_ATTR lrck_interrupt_handler(void *arg) {
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lrck_count+=1;
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}
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// Initialize GPIO interrupt for LRCK
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void init_lrck_monitor() {
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gpio_config_t io_conf = {
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.pin_bit_mask = (1ULL << RX_I2S_LRC),
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.mode = GPIO_MODE_INPUT,
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.pull_up_en = GPIO_PULLUP_DISABLE,
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.pull_down_en = GPIO_PULLDOWN_DISABLE,
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.intr_type = GPIO_INTR_POSEDGE // Interrupt bei steigender Flanke
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};
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gpio_config(&io_conf);
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gpio_install_isr_service(0);
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gpio_isr_handler_add((gpio_num_t)RX_I2S_LRC, lrck_interrupt_handler, NULL);
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}
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// calculate samplerates based on LRCK counter
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uint32_t measure_samplerate() {
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lrck_count = 0;
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vTaskDelay(MEASUREMENT_INTERVAL_MS / portTICK_PERIOD_MS);
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uint32_t samplerate = (lrck_count * 1000) / MEASUREMENT_INTERVAL_MS; // Hz
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return samplerate;
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}
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// check whether samplerates are one of the expected values
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uint32_t map_to_valid_samplerate(uint32_t measured) {
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const uint32_t valid_rates[] = {8000, 22050, 44100, 48000};
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const uint32_t num_rates = sizeof(valid_rates) / sizeof(valid_rates[0]);
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uint32_t closest_rate = valid_rates[0];
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int min_diff = abs((int)measured - (int)valid_rates[0]);
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for (int i = 1; i < num_rates; i++) {
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int diff = abs((int)measured - (int)valid_rates[i]);
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if (diff < min_diff) {
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min_diff = diff;
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closest_rate = valid_rates[i];
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}
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}
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// check tolerance
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if (min_diff <= (closest_rate * TOLERANCE_PERCENT / 100)) {
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return closest_rate;
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}
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return 0; // Invalid samplerates
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}
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// task to monitor the samplerates
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void samplerate_monitor_task(void *pvParameters) {
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init_lrck_monitor();
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while (1) {
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uint32_t new_samplerate = map_to_valid_samplerate(measure_samplerate());
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if (new_samplerate != 0 && new_samplerate != current_samplerate) {
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log_w("Samplerate changed to %u Hz", new_samplerate);
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resampler.setInputSamplerate(new_samplerate);
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// response to samplerates change
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if (new_samplerate == 48000) {
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log_w("Activating resampling to 44100 Hz");
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// activate resampling logic here
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} else if (new_samplerate == 44100) {
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log_w("No resampling needed");
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// deactivate Resampling, direct transmission
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} else {
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log_w("Unsupported samplerate: %u Hz", new_samplerate);
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// treat 8000 or 22050 Hz, if necessary
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}
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current_samplerate = new_samplerate;
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}
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vTaskDelay(500 / portTICK_PERIOD_MS); // Prüfe alle 500 ms
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}
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}
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//---------------------------------------------------------------------------------------------------------------------
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void i2s_install(){
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i2s_chan_cfg.id = (i2s_port_t)i2s_num; // I2S_NUM_AUTO, I2S_NUM_0, I2S_NUM_1
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i2s_chan_cfg.role = I2S_ROLE_SLAVE; // I2S controller slave role, bclk and lrc signal will be set to input
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i2s_chan_cfg.dma_desc_num = 8; // number of DMA buffer
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i2s_chan_cfg.dma_frame_num = 512; // I2S frame number in one DMA buffer.
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i2s_chan_cfg.auto_clear = true; // i2s will always send zero automatically if no data to send
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i2s_new_channel(&i2s_chan_cfg, NULL, &i2s_rx_handle);
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i2s_std_cfg.slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO); // Set to enable bit shift in Philips mode
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i2s_std_cfg.gpio_cfg.bclk = (gpio_num_t)RX_I2S_BCLK; // BCLK Assignment
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i2s_std_cfg.gpio_cfg.din = (gpio_num_t)RX_I2S_DIN; // DIN Assignment
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i2s_std_cfg.gpio_cfg.dout = I2S_GPIO_UNUSED; //
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i2s_std_cfg.gpio_cfg.mclk = I2S_GPIO_UNUSED; //
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i2s_std_cfg.gpio_cfg.ws = (gpio_num_t)RX_I2S_LRC; // LRC Assignment
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i2s_std_cfg.gpio_cfg.invert_flags.mclk_inv = false;
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i2s_std_cfg.gpio_cfg.invert_flags.bclk_inv = false;
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i2s_std_cfg.gpio_cfg.invert_flags.ws_inv = false;
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i2s_std_cfg.clk_cfg.sample_rate_hz = 44800;
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i2s_std_cfg.clk_cfg.clk_src = I2S_CLK_SRC_DEFAULT; // Select PLL_F160M as the default source clock
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i2s_std_cfg.clk_cfg.mclk_multiple = I2S_MCLK_MULTIPLE_128; //
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i2s_channel_init_std_mode(i2s_rx_handle, &i2s_std_cfg);
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i2s_channel_enable(i2s_rx_handle);
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}
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//---------------------------------------------CallBacks--------------------------------------------------------------------
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int32_t get_data(uint8_t *data, int32_t bytes) {
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return resampler.getData(data, bytes); // Holt exakt die benötigten Daten
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}
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// gets called when button on bluetooth speaker is pressed
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void button_handler(uint8_t id, bool isReleased){
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if (isReleased) {
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Serial.print("button id ");
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Serial.print(id);
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Serial.println(" released");
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}
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}
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//---------------------------------------------SETUP--------------------------------------------------------------------
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void setup(){
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Serial.begin(115200);
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i2s_install();
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a2dp_source.set_data_callback(get_data);
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a2dp_source.set_avrc_passthru_command_callback(button_handler);
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a2dp_source.start(BT_SINK_NAME);
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resampler.setChannelHandle(i2s_rx_handle);
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xTaskCreate(samplerate_monitor_task, "samplerate_monitor", 2048, NULL, 5, NULL);
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}
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//----------------------------------------------LOOP--------------------------------------------------------------------
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void loop() {
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vTaskDelay(1);
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resampler.loopResample();
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} |