diff options
Diffstat (limited to 'main.cpp')
| -rw-r--r-- | main.cpp | 51 |
1 files changed, 28 insertions, 23 deletions
@@ -9,31 +9,31 @@ static constexpr auto& WEIGHTING = A_weighting; static constexpr auto& MIC_EQUALIZER = SPH0645LM4H_B_RB; -static constexpr sos_t MIC_OFFSET_DB ( 0.f); // Linear offset -static constexpr sos_t MIC_SENSITIVITY (-26.f); // dBFS value expected at MIC_REF_DB -static constexpr sos_t MIC_REF_DB ( 94.f); // dB where sensitivity is specified +static constexpr float MIC_OFFSET_DB ( 0.f); // Linear offset +static constexpr float MIC_SENSITIVITY (-26.f); // dBFS value expected at MIC_REF_DB +static constexpr float MIC_REF_DB ( 94.f); // dB where sensitivity is specified static constexpr sos_t MIC_OVERLOAD_DB (120.f); // dB - Acoustic overload point static constexpr sos_t MIC_NOISE_DB ( 29.f); // dB - Noise floor -static constexpr auto MIC_BITS = 16u; // SPH0645 is actually 18 bits -static constexpr auto SAMPLE_RATE = 32000u; +static constexpr auto MIC_BITS = 18u; +static constexpr auto SAMPLE_RATE = 48000u; -static constexpr unsigned I2S_BUFSIZ = 512; // was 1024 -static constexpr unsigned I2S_STRIDE = 16; // was 8 +static constexpr unsigned I2S_BUFSIZ = 1024; +static constexpr unsigned I2S_STRIDE = 16; // Calculate reference amplitude value at compile time -static const auto MIC_REF_AMPL = fpm::pow(sos_t(10), MIC_SENSITIVITY / 20) * +static const auto MIC_REF_AMPL = qfp_fpow(10.f, MIC_SENSITIVITY / 20) * ((1 << (MIC_BITS - 1)) - 1); static SEMAPHORE_DECL(i2sReady, 0); static THD_WORKING_AREA(waThread1, 128); static std::array<uint32_t, I2S_BUFSIZ> i2sBuffer; -static sos_t Leq_sum_sqr (0); +static sos_t Leq_sum_sqr (0.f); static unsigned Leq_samples = 0; static THD_FUNCTION(Thread1, arg); static void i2sCallback(I2SDriver *i2s); -static constexpr auto I2SPRval = SAMPLE_RATE * 64 / 1000 / 1024 * 2; +static constexpr unsigned I2SPRval = 16'000'000 / SAMPLE_RATE / 32 / 2; static constexpr I2SConfig i2sConfig = { /* TX buffer */ NULL, /* RX buffer */ i2sBuffer.data(), @@ -43,11 +43,11 @@ static constexpr I2SConfig i2sConfig = { (0 << SPI_I2SCFGR_I2SSTD_Pos) | // Philips I2S (1 << SPI_I2SCFGR_DATLEN_Pos) | // 24-bit SPI_I2SCFGR_CHLEN, // 32-bit frame - /* I2SPR */ I2SPRval | (((I2SPRval / 2) & 1) ? SPI_I2SPR_ODD : 0) + /* I2SPR */ (I2SPRval / 2) | ((I2SPRval & 1) ? SPI_I2SPR_ODD : 0) }; THD_TABLE_BEGIN - THD_TABLE_THREAD(0, "blinker1", waThread1, Thread1, NULL) + THD_TABLE_THREAD(0, "main", waThread1, Thread1, NULL) THD_TABLE_END int main(void) @@ -64,6 +64,7 @@ THD_FUNCTION(Thread1, arg) chThdSleepMilliseconds(2000); + palSetPadMode(GPIOB, 7, PAL_MODE_OUTPUT_PUSHPULL); palSetPadMode(GPIOF, 2, PAL_MODE_UNCONNECTED); palSetLineMode(LINE_I2S_SD, PAL_MODE_ALTERNATE(0)); palSetLineMode(LINE_I2S_WS, PAL_MODE_ALTERNATE(0)); @@ -79,12 +80,13 @@ THD_FUNCTION(Thread1, arg) uint8_t strbuf[7] = { 0, 0, 0, 'd', 'B', '\n', '\0' }; for (;;) { + palSetPad(GPIOB, 7); chSemWait(&i2sReady); - const auto Leq_RMS = fpm::sqrt(Leq_sum_sqr / Leq_samples); + const auto Leq_RMS = qfp_fsqrt((float)Leq_sum_sqr / Leq_samples); const auto Leq_dB = MIC_OFFSET_DB + MIC_REF_DB + 20 * - fpm::log10(Leq_RMS / MIC_REF_AMPL); - Leq_sum_sqr = sos_t(0); + qfp_flog10(Leq_RMS / MIC_REF_AMPL); + Leq_sum_sqr = sos_t(0.f); Leq_samples = 0; auto n = std::clamp(static_cast<int32_t>(Leq_dB), 0l, 999l); @@ -92,22 +94,24 @@ THD_FUNCTION(Thread1, arg) strbuf[1] = n % 10 + '0'; n /= 10; strbuf[0] = n ? n + '0' : ' '; sdWrite(&SD2, strbuf, sizeof(strbuf)); + palClearPad(GPIOB, 7); } } +int32_t fixsample(uint32_t s) { + return (int32_t)(((s & 0xFFFF) << 16) | (s >> 16)) >> (32 - MIC_BITS); +} + void i2sCallback(I2SDriver *i2s) { - // Note: samples come in as 16-bit big-endian, so for simplicity we just - // take the "high" 16-bits of valid data and drop the rest. Mic is - // technically 18-bit, so we are losing some precision. - + palSetPad(GPIOB, 7); const auto halfsize = i2sBuffer.size() / 2; const auto offset = i2sIsBufferComplete(i2s) ? halfsize : 0; auto samples = reinterpret_cast<sos_t *>(i2sBuffer.data() + offset); std::ranges::copy( - std::views::counted(i2sBuffer.begin() + offset, halfsize) - | std::ranges::views::stride(2 * I2S_STRIDE) - | std::views::transform([](auto s) { return sos_t((int16_t)s); }), + std::views::counted(i2sBuffer.begin() + offset, halfsize / I2S_STRIDE) + | std::ranges::views::stride(2) + | std::views::transform([](uint32_t s) { return sos_t(fixsample(s)); }), samples); auto samps = std::views::counted(samples, halfsize / (2 * I2S_STRIDE)); @@ -117,8 +121,9 @@ void i2sCallback(I2SDriver *i2s) Leq_samples += samps.size(); // Wakeup main thread for dB calculation every second - if (Leq_samples >= 2 * SAMPLE_RATE / I2S_STRIDE) { + if (Leq_samples >= SAMPLE_RATE / I2S_STRIDE) { chSemSignalI(&i2sReady); } + palClearPad(GPIOB, 7); } |