initial commit

lib/audio_input/library.json

@@ -0,0 +1,5 @@
+{
+    "build": {
+        "flags": "-Ofast"
+    }
+}

lib/audio_input/src/ADCSampler.cpp

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+#include "ADCSampler.h"
+
+#if CONFIG_IDF_TARGET_ESP32 || CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
+
+ADCSampler::ADCSampler(adc_unit_t adcUnit, adc1_channel_t adcChannel, const i2s_config_t &i2s_config) : I2SSampler(I2S_NUM_0, i2s_config)
+{
+    m_adcUnit = adcUnit;
+    m_adcChannel = adcChannel;
+}
+
+void ADCSampler::configureI2S()
+{
+    //init ADC pad
+    i2s_set_adc_mode(m_adcUnit, m_adcChannel);
+    // enable the adc
+    i2s_adc_enable(m_i2sPort);
+}
+
+int ADCSampler::read(int16_t *samples, int count)
+{
+    // read from i2s
+    size_t bytes_read = 0;
+    i2s_read(m_i2sPort, samples, sizeof(int16_t) * count, &bytes_read, portMAX_DELAY);
+    int samples_read = bytes_read / sizeof(int16_t);
+    for (int i = 0; i < samples_read; i++)
+    {
+        samples[i] = (2048 - (uint16_t(samples[i]) & 0xfff)) * 15;
+    }
+    return samples_read;
+}
+
+#endif

lib/audio_input/src/ADCSampler.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <driver/adc.h>
+#include "I2SSampler.h"
+
+class ADCSampler : public I2SSampler
+{
+private:
+    adc_unit_t m_adcUnit;
+    adc1_channel_t m_adcChannel;
+
+protected:
+    void configureI2S();
+
+public:
+    ADCSampler(adc_unit_t adc_unit, adc1_channel_t adc_channel, const i2s_config_t &i2s_config);
+    virtual int read(int16_t *samples, int count);
+};

lib/audio_input/src/I2SMEMSSampler.cpp

@@ -0,0 +1,52 @@
+#include "I2SMEMSSampler.h"
+#include "soc/i2s_reg.h"
+
+I2SMEMSSampler::I2SMEMSSampler(
+    i2s_port_t i2s_port,
+    i2s_pin_config_t &i2s_pins,
+    i2s_config_t i2s_config,
+    int raw_samples_size,
+    bool fixSPH0645) : I2SSampler(i2s_port, i2s_config)
+{
+    m_i2sPins = i2s_pins;
+    m_fixSPH0645 = fixSPH0645;
+    m_raw_samples_size = raw_samples_size;
+    m_raw_samples = (int32_t *)malloc(sizeof(int32_t) * raw_samples_size);
+}
+
+I2SMEMSSampler::~I2SMEMSSampler() 
+{
+  free(m_raw_samples);
+}
+
+void I2SMEMSSampler::configureI2S()
+{
+    if (m_fixSPH0645)
+    {
+        // FIXES for SPH0645
+#if CONFIG_IDF_TARGET_ESP32 || CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
+        REG_SET_BIT(I2S_TIMING_REG(m_i2sPort), BIT(9));
+        REG_SET_BIT(I2S_CONF_REG(m_i2sPort), I2S_RX_MSB_SHIFT);
+#endif
+    }
+
+    i2s_set_pin(m_i2sPort, &m_i2sPins);
+}
+
+int I2SMEMSSampler::read(int16_t *samples, int count)
+{
+    // read from i2s
+    size_t bytes_read = 0;
+    if (count>m_raw_samples_size)
+    {
+        count = m_raw_samples_size; // Buffer is too small
+    }
+    i2s_read(m_i2sPort, m_raw_samples, sizeof(int32_t) * count, &bytes_read, portMAX_DELAY);
+    int samples_read = bytes_read / sizeof(int32_t);
+    for (int i = 0; i < samples_read; i++)
+    {
+        int32_t temp = m_raw_samples[i] >> 11;
+        samples[i] = (temp > INT16_MAX) ? INT16_MAX : (temp < -INT16_MAX) ? -INT16_MAX : (int16_t)temp;
+    }
+    return samples_read;
+}

lib/audio_input/src/I2SMEMSSampler.h

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+#pragma once
+
+#include "I2SSampler.h"
+
+class I2SMEMSSampler : public I2SSampler
+{
+private:
+    i2s_pin_config_t m_i2sPins;
+    bool m_fixSPH0645;
+    int32_t *m_raw_samples;
+    int m_raw_samples_size;
+
+protected:
+    void configureI2S();
+
+public:
+    I2SMEMSSampler(
+        i2s_port_t i2s_port,
+        i2s_pin_config_t &i2s_pins,
+        i2s_config_t i2s_config,
+        int raw_samples_size,
+        bool fixSPH0645 = false);
+    ~I2SMEMSSampler();
+    virtual int read(int16_t *samples, int count);
+};

lib/audio_input/src/I2SSampler.cpp

@@ -0,0 +1,21 @@
+
+#include "I2SSampler.h"
+#include "driver/i2s.h"
+
+I2SSampler::I2SSampler(i2s_port_t i2sPort, const i2s_config_t &i2s_config) : m_i2sPort(i2sPort), m_i2s_config(i2s_config)
+{
+}
+
+void I2SSampler::start()
+{
+    //install and start i2s driver
+    i2s_driver_install(m_i2sPort, &m_i2s_config, 0, NULL);
+    // set up the I2S configuration from the subclass
+    configureI2S();
+}
+
+void I2SSampler::stop()
+{
+    // stop the i2S driver
+    i2s_driver_uninstall(m_i2sPort);
+}

lib/audio_input/src/I2SSampler.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <freertos/FreeRTOS.h>
+#include <driver/i2s.h>
+
+/**
+ * Base Class for both the ADC and I2S sampler
+ **/
+class I2SSampler
+{
+protected:
+    i2s_port_t m_i2sPort = I2S_NUM_0;
+    i2s_config_t m_i2s_config;
+    virtual void configureI2S() = 0;
+    virtual void processI2SData(void *samples, size_t count){
+        // nothing to do for the default case
+    };
+
+public:
+    I2SSampler(i2s_port_t i2sPort, const i2s_config_t &i2sConfig);
+    void start();
+    virtual int read(int16_t *samples, int count) = 0;
+    void stop();
+    int sample_rate()
+    {
+        return m_i2s_config.sample_rate;
+    }
+};