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feat ✨: Updated src/main.cpp to utilize FormatConverterStream for converting 32-bit I2S input to 16-bit output and configured an AudioFFTBase with the correct bits per sample

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- Modified `src/main.cpp` to use `FormatConverterStream` for converting 32-bit I2S input to 16-bit output, then configured an `AudioFFTBase` with the appropriate bits per sample.
This commit is contained in:
Jose
2025-04-18 21:48:47 +02:00
parent 83a594cdd9
commit 9a3d026176
1 changed files with 17 additions and 6 deletions
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21
src/main.cpp
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@@ -4,11 +4,16 @@
I2SStream i2sStream; // I2S input stream for INMP441 I2SStream i2sStream; // I2S input stream for INMP441
AudioRealFFT fft; // FFT analyzer AudioRealFFT fft; // FFT analyzer
StreamCopy copier(fft, i2sStream); // copy I2S mic to FFT FormatConverterStream converter(i2sStream); // Convert 32-bit input to 16-bit output
StreamCopy copier(fft, converter); // copy converted data to FFT
int channels = 1; // INMP441 is mono int channels = 1; // INMP441 is mono
int samples_per_second = 11025; int samples_per_second = 11025;
int bits_per_sample = 32; // INMP441 sends 24-bit data in 32-bit words int input_bits_per_sample = 32; // INMP441 sends 24-bit data in 32-bit words
int fft_bits_per_sample = 16;
AudioInfo from(samples_per_second, channels, input_bits_per_sample);
AudioInfo to(samples_per_second, channels, fft_bits_per_sample);
const char* solfegeName(uint8_t midiNote) { const char* solfegeName(uint8_t midiNote) {
static const char* solfegeNames[] = { static const char* solfegeNames[] = {
@@ -30,7 +35,7 @@ void fftResult(AudioFFTBase &fft) {
const char* solfege = solfegeName(midiNote); const char* solfege = solfegeName(midiNote);
int octave = (midiNote / 12) - 1; int octave = (midiNote / 12) - 1;
Serial.print(freq, 2); Serial.print(freq, 0);
Serial.print(" Hz | "); Serial.print(" Hz | ");
Serial.print("MIDI "); Serial.print("MIDI ");
@@ -50,6 +55,9 @@ void fftResult(AudioFFTBase &fft) {
Serial.print(" | Diff: "); Serial.print(" | Diff: ");
Serial.println(diff, 2); Serial.println(diff, 2);
Serial.print(" | Amp: ");
Serial.println(result.magnitude, 0);
} }
} }
@@ -61,7 +69,7 @@ void setup() {
// Configure I2SStream for INMP441 // Configure I2SStream for INMP441
auto cfg = i2sStream.defaultConfig(RX_MODE); auto cfg = i2sStream.defaultConfig(RX_MODE);
cfg.i2s_format = I2S_STD_FORMAT; cfg.i2s_format = I2S_STD_FORMAT;
cfg.bits_per_sample = bits_per_sample; cfg.bits_per_sample = input_bits_per_sample;
cfg.channels = channels; cfg.channels = channels;
cfg.sample_rate = samples_per_second; cfg.sample_rate = samples_per_second;
cfg.is_master = true; cfg.is_master = true;
@@ -70,12 +78,15 @@ void setup() {
cfg.pin_data = 10; // SD cfg.pin_data = 10; // SD
i2sStream.begin(cfg); i2sStream.begin(cfg);
// Configure FormatConverterStream to convert 32-bit to 16-bit
converter.begin(from, to); // Convert to 16-bit
// Configure FFT // Configure FFT
auto tcfg = fft.defaultConfig(); auto tcfg = fft.defaultConfig();
tcfg.length = 8192; // 186ms @ 11kHz minimun C2 theoretical tcfg.length = 8192; // 186ms @ 11kHz minimun C2 theoretical
tcfg.channels = channels; tcfg.channels = channels;
tcfg.sample_rate = samples_per_second; tcfg.sample_rate = samples_per_second;
tcfg.bits_per_sample = bits_per_sample; tcfg.bits_per_sample = fft_bits_per_sample; // FFT expects 16-bit data after conversion
tcfg.callback = &fftResult; tcfg.callback = &fftResult;
fft.begin(tcfg); fft.begin(tcfg);