Resources needed for STM32H743 SAI1 + PCM3060 (hardware control mode) integration using STM32CubeIDE

Hardware Development
1

Hi everyone,

I’m working on a project where I need to interface an STM32H743 microcontroller with a PCM3060 audio codec from scratch using STM32CubeIDE. The PCM3060 is wired in hardware control mode, and I plan to use the SAI1 peripheral for audio data transfer.

What I’m trying to achieve:

  • Interface with PCM3060 audio codec in hardware control mode
  • Configure STM32H743 SAI1 peripheral for audio data transfer
  • Set up proper clock domains and SAI timing
  • Handle audio data flow (ADC/DAC) through SAI1
  • Build the project from the ground up in STM32CubeIDE

What I’m looking for:

  • Reference designs or application notes for PCM3060 in hardware mode
  • STM32H7 SAI1 configuration examples for audio applications
  • Code examples showing SAI1 setup, DMA configuration, and data handling
  • Documentation on SAI clock configuration and PLL setup for audio
  • SAI1 timing requirements and PCM3060 synchronization
  • CubeMX configuration tips for SAI1 audio projects
  • Any gotchas or common pitfalls to avoid

My current experience level:
i am not a beginner but i’m sure i can build something with a few indications

Since the codec is in hardware control mode, I mainly need help with the STM32 SAI1 configuration and audio data flow implementation.

Any help, links to resources, or guidance would be greatly appreciated!

Thanks in advance!

2

Daisy Seed uses PCM3060 in hardware control mode, that should help you with the code.
The hardware pins look easy to figure out.

3

hello
i am able to get some sound from my output. i can hear kind of hear my guitar when i play the strings but it’s still very distorted. there’s a lot of noise

4

i was able to get a clean signal from the codec. I just implemented a pass through for now. I’'ll see what i can add to this

hsai_BlockA1.Instance = SAI1_Block_A;
  hsai_BlockA1.Init.AudioMode = SAI_MODEMASTER_TX;
  hsai_BlockA1.Init.Synchro = SAI_ASYNCHRONOUS;
  hsai_BlockA1.Init.OutputDrive = SAI_OUTPUTDRIVE_ENABLE;
  hsai_BlockA1.Init.NoDivider = SAI_MCK_OVERSAMPLING_DISABLE;
  hsai_BlockA1.Init.MckOverSampling = SAI_MCK_OVERSAMPLING_DISABLE;
  hsai_BlockA1.Init.FIFOThreshold = SAI_FIFOTHRESHOLD_1QF;
  hsai_BlockA1.Init.AudioFrequency = SAI_AUDIO_FREQUENCY_48K;
  hsai_BlockA1.Init.SynchroExt = SAI_SYNCEXT_DISABLE;
  hsai_BlockA1.Init.MonoStereoMode = SAI_STEREOMODE;
  hsai_BlockA1.Init.CompandingMode = SAI_NOCOMPANDING;
  hsai_BlockA1.Init.TriState = SAI_OUTPUT_NOTRELEASED;
  if (HAL_SAI_InitProtocol(&hsai_BlockA1, SAI_I2S_MSBJUSTIFIED, SAI_PROTOCOL_DATASIZE_24BIT, 2) != HAL_OK)
  {
    Error_Handler();
  }
  hsai_BlockB1.Instance = SAI1_Block_B;
  hsai_BlockB1.Init.AudioMode = SAI_MODESLAVE_RX;
  hsai_BlockB1.Init.Synchro = SAI_SYNCHRONOUS;
  hsai_BlockB1.Init.OutputDrive = SAI_OUTPUTDRIVE_DISABLE;
  hsai_BlockB1.Init.MckOverSampling = SAI_MCK_OVERSAMPLING_ENABLE;
  hsai_BlockB1.Init.FIFOThreshold = SAI_FIFOTHRESHOLD_1QF;
  hsai_BlockB1.Init.SynchroExt = SAI_SYNCEXT_DISABLE;
  hsai_BlockB1.Init.MonoStereoMode = SAI_STEREOMODE;
  hsai_BlockB1.Init.CompandingMode = SAI_NOCOMPANDING;
  hsai_BlockB1.Init.TriState = SAI_OUTPUT_NOTRELEASED;
  if (HAL_SAI_InitProtocol(&hsai_BlockB1, SAI_I2S_MSBJUSTIFIED, SAI_PROTOCOL_DATASIZE_24BIT, 2) != HAL_OK)
  {
    Error_Handler();
  }

this is my init sequence, is there something i should change?

5

the clean sound work just great. but i noticed that when i try to add effects to it the signal just gets distorted. a lot

any ideas on how to prevent this

#include "tremolo.h"
#include <math.h>

#define TWO_PI (2.0f * 3.1415926535f)
#define MIN_RATE 0.1f
#define MAX_RATE 10.0f
#define MIN_DEPTH 0.0f
#define MAX_DEPTH 0.95f  // Leave some headroom

void Tremolo_Init(Tremolo* trem, uint32_t sample_rate) 
{
    trem->rate_hz = 2.0f;  // Default 2Hz
    trem->depth = 0.5f;    // Default 50% depth
    trem->phase = 0.0f;
    trem->sample_rate = sample_rate;
    trem->phase_inc = TWO_PI * trem->rate_hz / (float)sample_rate;
    trem->smoothed_lfo = 1.0f;  // Start at unity gain
}

void Tremolo_SetRate(Tremolo* trem, float rate_hz) 
{
    // Constrain rate and convert to phase increment
    trem->rate_hz = (rate_hz < MIN_RATE) ? MIN_RATE : 
                   ((rate_hz > MAX_RATE) ? MAX_RATE : rate_hz);
    trem->phase_inc = TWO_PI * trem->rate_hz / (float)trem->sample_rate;
}

void Tremolo_SetDepth(Tremolo* trem, float depth) 
{
    // Constrain depth to safe range
    trem->depth = (depth < MIN_DEPTH) ? MIN_DEPTH : 
                 ((depth > MAX_DEPTH) ? MAX_DEPTH : depth);
}

float Tremolo_Process(Tremolo* trem, float input) 
{
    // Generate triangle wave LFO (smoother than sine for tremolo)
    float lfo_pos = fmodf(trem->phase / TWO_PI, 1.0f);
    float raw_lfo = 1.0f - trem->depth * (1.0f - fabsf(2.0f * lfo_pos - 1.0f));
    
    // Smooth LFO transitions to prevent clicks
    trem->smoothed_lfo = 0.25f * raw_lfo + 0.75f * trem->smoothed_lfo;
    
    // Update phase
    trem->phase += trem->phase_inc;
    if (trem->phase > TWO_PI * 4.0f) {  // Keep phase bounded
        trem->phase -= TWO_PI * 4.0f;
    }
    
    // Apply modulation with 10% minimum gain to avoid silence
    return input * (0.1f + 0.8f * trem->smoothed_lfo);
}

this is what the tremolo code would look like and i would apply it like this

void GuitarPedal_ProcessAudio(...) {
    if(tremolo_enabled) {
        float in_sample = (float)input[i].left / 8388608.0f; // 24-bit to float
        float out_sample = Tremolo_Process(&tremolo, in_sample);
        output[i].left = (int32_t)(out_sample * 8388608.0f);
    }
}

but i always get distorted sound like very distorted, not pleasant to hear

i also want to know what is the default sample rate when the pcm3060 is used in hardware mode

6

In case other community members come across this, I’ll share the thread where you were able to resolve it with tele_player :slight_smile:

1 Like