Allow i2s microphone bits per sample to be configured (#4884)

esphome/components/i2s_audio/microphone/__init__.py

@@ -20,6 +20,7 @@ DEPENDENCIES = ["i2s_audio"]
 CONF_ADC_PIN = "adc_pin"
 CONF_ADC_TYPE = "adc_type"
 CONF_PDM = "pdm"
+CONF_BITS_PER_SAMPLE = "bits_per_sample"
 
 I2SAudioMicrophone = i2s_audio_ns.class_(
     "I2SAudioMicrophone", I2SAudioIn, microphone.Microphone, cg.Component
@@ -30,10 +31,17 @@ CHANNELS = {
     "left": i2s_channel_fmt_t.I2S_CHANNEL_FMT_ONLY_LEFT,
     "right": i2s_channel_fmt_t.I2S_CHANNEL_FMT_ONLY_RIGHT,
 }
+i2s_bits_per_sample_t = cg.global_ns.enum("i2s_bits_per_sample_t")
+BITS_PER_SAMPLE = {
+    16: i2s_bits_per_sample_t.I2S_BITS_PER_SAMPLE_16BIT,
+    32: i2s_bits_per_sample_t.I2S_BITS_PER_SAMPLE_32BIT,
+}
 
 INTERNAL_ADC_VARIANTS = [esp32.const.VARIANT_ESP32]
 PDM_VARIANTS = [esp32.const.VARIANT_ESP32, esp32.const.VARIANT_ESP32S3]
 
+_validate_bits = cv.float_with_unit("bits", "bit")
+
 
 def validate_esp32_variant(config):
     variant = esp32.get_esp32_variant()
@@ -54,6 +62,9 @@ BASE_SCHEMA = microphone.MICROPHONE_SCHEMA.extend(
         cv.GenerateID(): cv.declare_id(I2SAudioMicrophone),
         cv.GenerateID(CONF_I2S_AUDIO_ID): cv.use_id(I2SAudioComponent),
         cv.Optional(CONF_CHANNEL, default="right"): cv.enum(CHANNELS),
+        cv.Optional(CONF_BITS_PER_SAMPLE, default="16bit"): cv.All(
+            _validate_bits, cv.enum(BITS_PER_SAMPLE)
+        ),
     }
 ).extend(cv.COMPONENT_SCHEMA)
 
@@ -93,6 +104,7 @@ async def to_code(config):
         cg.add(var.set_din_pin(config[CONF_I2S_DIN_PIN]))
         cg.add(var.set_pdm(config[CONF_PDM]))
 
-    cg.add(var.set_channel(CHANNELS[config[CONF_CHANNEL]]))
+    cg.add(var.set_channel(config[CONF_CHANNEL]))
+    cg.add(var.set_bits_per_sample(config[CONF_BITS_PER_SAMPLE]))
 
     await microphone.register_microphone(var, config)

esphome/components/i2s_audio/microphone/i2s_audio_microphone.cpp

@@ -16,7 +16,13 @@ static const char *const TAG = "i2s_audio.microphone";
 
 void I2SAudioMicrophone::setup() {
   ESP_LOGCONFIG(TAG, "Setting up I2S Audio Microphone...");
-  this->buffer_.resize(BUFFER_SIZE);
+  ExternalRAMAllocator<uint8_t> allocator(ExternalRAMAllocator<uint8_t>::ALLOW_FAILURE);
+  this->buffer_ = allocator.allocate(BUFFER_SIZE);
+  if (this->buffer_ == nullptr) {
+    ESP_LOGE(TAG, "Failed to allocate buffer!");
+    this->mark_failed();
+    return;
+  }
 
 #if SOC_I2S_SUPPORTS_ADC
   if (this->adc_) {
@@ -48,7 +54,7 @@ void I2SAudioMicrophone::start_() {
   i2s_driver_config_t config = {
       .mode = (i2s_mode_t) (I2S_MODE_MASTER | I2S_MODE_RX),
       .sample_rate = 16000,
-      .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
+      .bits_per_sample = this->bits_per_sample_,
       .channel_format = this->channel_,
       .communication_format = I2S_COMM_FORMAT_STAND_I2S,
       .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
@@ -107,16 +113,35 @@ void I2SAudioMicrophone::stop_() {
 void I2SAudioMicrophone::read_() {
   size_t bytes_read = 0;
   esp_err_t err =
-      i2s_read(this->parent_->get_port(), this->buffer_.data(), BUFFER_SIZE, &bytes_read, (100 / portTICK_PERIOD_MS));
+      i2s_read(this->parent_->get_port(), this->buffer_, BUFFER_SIZE, &bytes_read, (100 / portTICK_PERIOD_MS));
   if (err != ESP_OK) {
     ESP_LOGW(TAG, "Error reading from I2S microphone: %s", esp_err_to_name(err));
     this->status_set_warning();
     return;
   }
-
   this->status_clear_warning();
 
-  this->data_callbacks_.call(this->buffer_);
+  std::vector<int16_t> samples;
+  size_t samples_read = 0;
+  if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_16BIT) {
+    samples_read = bytes_read / sizeof(int16_t);
+  } else if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_32BIT) {
+    samples_read = bytes_read / sizeof(int32_t);
+  } else {
+    ESP_LOGE(TAG, "Unsupported bits per sample: %d", this->bits_per_sample_);
+    return;
+  }
+  samples.resize(samples_read);
+  if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_16BIT) {
+    memcpy(samples.data(), this->buffer_, bytes_read);
+  } else if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_32BIT) {
+    for (size_t i = 0; i < samples_read; i++) {
+      int32_t temp = reinterpret_cast<int32_t *>(this->buffer_)[i] >> 14;
+      samples[i] = clamp<int16_t>(temp, INT16_MIN, INT16_MAX);
+    }
+  }
+
+  this->data_callbacks_.call(samples);
 }
 
 void I2SAudioMicrophone::loop() {

esphome/components/i2s_audio/microphone/i2s_audio_microphone.h

@@ -29,6 +29,7 @@ class I2SAudioMicrophone : public I2SAudioIn, public microphone::Microphone, pub
 #endif
 
   void set_channel(i2s_channel_fmt_t channel) { this->channel_ = channel; }
+  void set_bits_per_sample(i2s_bits_per_sample_t bits_per_sample) { this->bits_per_sample_ = bits_per_sample; }
 
  protected:
   void start_();
@@ -41,8 +42,9 @@ class I2SAudioMicrophone : public I2SAudioIn, public microphone::Microphone, pub
   bool adc_{false};
 #endif
   bool pdm_{false};
-  std::vector<uint8_t> buffer_;
+  uint8_t *buffer_;
   i2s_channel_fmt_t channel_;
+  i2s_bits_per_sample_t bits_per_sample_;
 
   HighFrequencyLoopRequester high_freq_;
 };