STM to ESP

[pito]

Is there a special reason for I2S?

no

[ivconic]

Lose I2S first.
Task:
4 channels PWM (2 sine + 2 square) on GPIO 14, 15, 16, 17

#include <Arduino.h>

#define PWM_FREQ_CARRIER 20000  // 20 kHz PWM carrier frequency for sine waves
#define PWM_RESOLUTION 8        // 8-bit resolution

#define SINE_SAMPLES 50
#define TWO_PI 6.28318530718

// GPIO pins for 4 PWM channels
const int pwmPins[4] = {14, 15, 16, 17};

// PWM channels for ESP32 LEDC (0-15)
const int pwmChannels[4] = {0, 1, 2, 3};

// Sine wave sample buffers (8-bit duty cycles)
uint8_t sineWave1[SINE_SAMPLES];
uint8_t sineWave2[SINE_SAMPLES];

float phase1 = 0;
float phase2 = 0;
float phaseStep1 = TWO_PI / SINE_SAMPLES;   // Adjust to set sine frequency
float phaseStep2 = TWO_PI / SINE_SAMPLES;

void setup() {
  Serial.begin(115200);

  // Generate sine wave lookup tables (duty cycles)
  for (int i = 0; i < SINE_SAMPLES; i++) {
    sineWave1[i] = 128 + 127 * sin(phaseStep1 * i); // 0..255 PWM duty
    sineWave2[i] = 128 + 127 * sin(phaseStep2 * i);
  }

  // Setup PWM channels for all pins
  for (int ch = 0; ch < 4; ch++) {
    ledcSetup(pwmChannels[ch], PWM_FREQ_CARRIER, PWM_RESOLUTION);
    ledcAttachPin(pwmPins[ch], pwmChannels[ch]);
  }
}

void loop() {
  // Advance sine wave phases for channels 1 and 2
  static int index1 = 0;
  static int index2 = 0;

  // Update PWM duty for sine wave channels
  ledcWrite(pwmChannels[0], sineWave1[index1]);  // PWM channel 0, GPIO14
  ledcWrite(pwmChannels[1], sineWave2[index2]);  // PWM channel 1, GPIO15

  // Square wave channels: 50% duty cycle PWM at desired freq
  // We simulate square wave frequencies by toggling duty cycle on slower time scale

  static unsigned long lastToggleTimeCh2 = 0;
  static unsigned long lastToggleTimeCh3 = 0;
  static bool squareStateCh2 = false;
  static bool squareStateCh3 = false;

  unsigned long now = millis();

  // Square wave channel 3 (GPIO16) toggle every 10 ms (50 Hz)
  if (now - lastToggleTimeCh2 >= 10) {
    squareStateCh2 = !squareStateCh2;
    ledcWrite(pwmChannels[2], squareStateCh2 ? 128 : 0); // 50% or 0% duty cycle
    lastToggleTimeCh2 = now;
  }

  // Square wave channel 4 (GPIO17) toggle every 5 ms (100 Hz)
  if (now - lastToggleTimeCh3 >= 5) {
    squareStateCh3 = !squareStateCh3;
    ledcWrite(pwmChannels[3], squareStateCh3 ? 128 : 0);
    lastToggleTimeCh3 = now;
  }

  // Advance sine wave sample index (control sine frequency here)
  index1 = (index1 + 1) % SINE_SAMPLES;
  index2 = (index2 + 1) % SINE_SAMPLES;

  delay(1); // small delay to control sine wave frequency (adjust as needed)
}
​

[ivconic]

Channels 0 & 1 (GPIO14 & GPIO15): PWM at 20 kHz carrier frequency with duty cycles modulated by sine wave lookup table.
Output needs low-pass RC filter to sound like sine wave analog output. RC low-pass filter (e.g., 10k resistor + 0.1uF capacitor)
Channels 2 & 3 (GPIO16 & GPIO17): Software toggling the duty cycle between 50% and 0% to create square waves of 50 Hz and 100 Hz frequencies approx.
PWM carrier frequency is still 20 kHz but the duty is toggled slowly for square wave frequency.

[pito]

post #17 3rror

C:\Users\Galinka\Documents\Arduino\4_channels_ivconic\4_channels_ivconic.ino: In function 'void setup()':
4_channels_ivconic:35:5: error: 'ledcSetup' was not declared in this scope
   35 |     ledcSetup(pwmChannels[ch], PWM_FREQ_CARRIER, PWM_RESOLUTION);
      |     ^~~~~~~~~
4_channels_ivconic:36:5: error: 'ledcAttachPin' was not declared in this scope; did you mean 'ledcAttach'?
   36 |     ledcAttachPin(pwmPins[ch], pwmChannels[ch]);
      |     ^~~~~~~~~~~~~
      |     ledcAttach
C:\Users\Galinka\Documents\Arduino\4_channels_ivconic\4_channels_ivconic.ino: At global scope:
4_channels_ivconic:79:1: error: '​' does not name a type
   79 | ​
      |  
exit status 1
'ledcSetup' was not declared in this scope​

[ivconic]

Missing include of the correct ESP32 LEDC driver library or Arduino core headers,
Typo or invisible characters in the code (like a zero-width space or non-printable character),
Or compiling the code with the wrong board selected (like a non-ESP32 board).

[ivconic]

Make sure you have selected ESP32 board in Arduino IDE
Go to Tools > Board > ESP32 Arduino > Your ESP32 board
If you don’t have ESP32 support installed, follow this guide: https://docs.espressif.com/projects/...nstalling.html
Include the right headers at the top of your sketch
cpp
#include <Arduino.h>
You probably already have it since ledcSetup and ledcAttachPin are part of the ESP32 Arduino core API.
But they do NOT need a separate include, just make sure your board is ESP32.
Remove invisible characters or trailing weird characters at the end of your file
Open your .ino in a text editor that can show hidden characters (e.g., VSCode, Notepad++) and remove any strange symbols.
***

If this minimal example fails to compile, you are either compiling for the wrong board or your ESP32 Arduino core installation is broken.
Minimal example that compiles on ESP32 (copy-paste as a test).

#include <Arduino.h>

const int pwmPin = 14;
const int pwmChannel = 0;
const int freq = 5000;
const int resolution = 8;

void setup() {
  ledcSetup(pwmChannel, freq, resolution);
  ledcAttachPin(pwmPin, pwmChannel);
  ledcWrite(pwmChannel, 128);
}

void loop() {
  // do nothing
}
​

[pito]

I almost did it, not sure yet about synchronization

#include "driver/i2s.h"
//https://esp32.com/viewtopic.php?p=144590&hilit=sin#p144590
#include "driver/i2s.h"
////////////////////////
#include <driver/ledc.h>
////////////////////////
#define SAMPLE_RATE 400000
//#define WAVEFORM_SAMPLES 256            //3kHz
//#define WAVEFORM_SAMPLES 100            // 8kHz
#define WAVEFORM_SAMPLES 50               //16 kHz

uint8_t stereo_buffer[WAVEFORM_SAMPLES * 2];
uint8_t wave_data1[WAVEFORM_SAMPLES];
uint8_t wave_data2[WAVEFORM_SAMPLES];
///////////////////
//const float amp = 127.5; // Half of the max value (255/2)
const float amp = 60;
const float stp = 0.1;  // Step size for the sine wave
float i = 0;
///////////////////
void generateWaveforms() {
  for (int i = 0; i < WAVEFORM_SAMPLES; i++) {
   wave_data1[i] = (uint8_t)((255 * i) / WAVEFORM_SAMPLES);
    wave_data2[i] = (uint8_t)(127.5 * (1 + sin(2 * 3.14159 * i / WAVEFORM_SAMPLES)));
     //wave_data1[i] = (uint8_t)(amp + amp * sin(stp * i));
     //   wave_data2[i] = (uint8_t)(amp + amp * sin(stp * i));
   // int dutyCycle = (int)(amp + amp * sin(stp * i)); // Calculate the duty cycle
  }
  for (int i = 0; i < WAVEFORM_SAMPLES; i++) {
    stereo_buffer[i * 2] = wave_data1[i];      // DAC1
    stereo_buffer[i * 2 + 1] = wave_data2[i];  // DAC2
  }
}

void setup() {
  Serial.begin(115200);
  //////////////////////
ledc_timer_config_t timerConfig = {
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .duty_resolution = LEDC_TIMER_10_BIT,
        .timer_num = LEDC_TIMER_0,
        .freq_hz = 16000,
        .clk_cfg = LEDC_AUTO_CLK
    };
    ledc_timer_config(&timerConfig);

    
    ledc_channel_config_t channelConfig1 = {
        .gpio_num = 12,
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .channel = LEDC_CHANNEL_0,
        .timer_sel = LEDC_TIMER_0,
        .duty = 512,
        .hpoint = 0
    };
    ledc_channel_config(&channelConfig1);

  
    ledc_channel_config_t channelConfig2 = {
        .gpio_num = 14,
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .channel = LEDC_CHANNEL_1,
        .timer_sel = LEDC_TIMER_0,
        .duty = 512,
        .hpoint = 0 // 0 deg
    };
    ledc_channel_config(&channelConfig2);
  /////////////////////////
  generateWaveforms();

  i2s_config_t i2s_config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN),
    .sample_rate = SAMPLE_RATE,
    .bits_per_sample = I2S_BITS_PER_SAMPLE_8BIT,
    .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
    .communication_format = I2S_COMM_FORMAT_I2S_MSB,
    .intr_alloc_flags = 0,
    .dma_buf_count = 8,
    .dma_buf_len = WAVEFORM_SAMPLES * 2,
    .use_apll = false,
  };

  i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_NUM_0, NULL);
  i2s_set_dac_mode(I2S_DAC_CHANNEL_BOTH_EN);
  i2s_set_sample_rates(I2S_NUM_0, i2s_config.sample_rate);
}

void loop() {
  size_t bytes_written;
  i2s_write(I2S_NUM_0, stereo_buffer, sizeof(stereo_buffer), &bytes_written, portMAX_DELAY);
}​
}​

[ivconic]

https://youtube.com/shorts/tV-HiK4J3...9tBhpZR-UGUoQM

[pito]

Make sure you have selected ESP32 board in Arduino IDE
Go to Tools > Board > ESP32 Arduino > Your ESP32 board
If you don’t have ESP32 support installed, follow this guide: https://docs.espressif.com/projects/...nstalling.html
Include the right headers at the top of your sketch
cpp
#include <Arduino.h>
You probably already have it since ledcSetup and ledcAttachPin are part of the ESP32 Arduino core API.
But they do NOT need a separate include, just make sure your board is ESP32.
Remove invisible characters or trailing weird characters at the end of your file
Open your .ino in a text editor that can show hidden characters (e.g., VSCode, Notepad++) and remove any strange symbols.
***

If this minimal example fails to compile, you are either compiling for the wrong board or your ESP32 Arduino core installation is broken.
Minimal example that compiles on ESP32 (copy-paste as a test).

#include <Arduino.h>

const int pwmPin = 14;
const int pwmChannel = 0;
const int freq = 5000;
const int resolution = 8;

void setup() {
ledcSetup(pwmChannel, freq, resolution);
ledcAttachPin(pwmPin, pwmChannel);
ledcWrite(pwmChannel, 128);
}

void loop() {
// do nothing
}
​error the same

[ivconic]

Pick one generic for staters.
Idea is to test your setup for now.

[pito]

Migration from 2.x to 3.0


https://docs.espressif.com/projects/..._3.0.html#ledc

[ivconic]

Oh right!
I have the older settings set for the ESP32S model that I use in my devices.
Experience has taught me; once you get the environment working properly: don't touch it again!
...
Open Arduino IDE → Tools → Board → Boards Manager.
Search for ESP32.
Make sure you're using ESP32 core v3.0.0 or newer.
...
Minimal working example (new API, ESP32 Arduino 3.x), just to test your environment:

#include <Arduino.h>
#include <math.h>

#define PWM_PIN 25
#define SAMPLES 130

int val1[SAMPLES];
int amp = 40;
float stp = 6.2831 / SAMPLES;
volatile int sample_index = 0;

hw_timer_t *timer = NULL;

void IRAM_ATTR onTimer() {
  ledcWrite(PWM_PIN, val1[sample_index]);
  sample_index = (sample_index + 1) % SAMPLES;
}

void init_wave() {
  for (int i = 0; i < SAMPLES; i++) {
    val1[i] = 40 + amp * sin(stp * i);  // values from 0 to 80
  }
}

void setup() {
  init_wave();

  // NEW: uses pin, frequency, resolution (bits)
  ledcAttach(PWM_PIN, 20000, 8);  // 20kHz, 8-bit resolution

  timer = timerBegin(0, 80, true);         // 1 MHz clock (80 MHz / 80)
  timerAttachInterrupt(timer, onTimer);    // no 3rd param in new API
  timerAlarmWrite(timer, 50, true);        // 50 µs interval
  timerAlarmEnable(timer);
}

void loop() {
  // Everything handled in interrupt
}

[ivconic]

Now it should compile fine:

#include <Arduino.h>
#include <math.h>

#define SAMPLES 130
#define PWM_PIN 25  // zamenjuje PB7
#define PWM_FREQ 20000  // 20kHz PWM nosilac
#define TIMER_US 50     // Tajmer interrupt svakih 50 μs

int val1[SAMPLES];
int amp = 40;
float stp = 6.2831 / SAMPLES;
volatile int sample_index = 0;

hw_timer_t *timer = NULL;

void IRAM_ATTR onTimer() {
  // imitira DMA slanje jedne vrednosti
  ledcWrite(PWM_PIN, val1[sample_index]);
  sample_index = (sample_index + 1) % SAMPLES;
}

void init_wave() {
  for (int i = 0; i < SAMPLES; i++) {
    val1[i] = 40 + amp * sin(stp * i);  // duty od 0 do 80 (8-bit LEDC)
  }
}

void setup() {
  init_wave();

  // Novi LEDC API: automatski dodeljuje kanal, koristi pin
  ledcAttach(PWM_PIN, PWM_FREQ, 8);  // 8-bit rezolucija, 20kHz

  // Timer 0, clock = 80 MHz / 80 = 1 MHz → 1 tick = 1μs
  timer = timerBegin(0, 80, true);
  timerAttachInterrupt(timer, &onTimer);
  timerAlarmWrite(timer, TIMER_US, true);
  timerAlarmEnable(timer);
}

void loop() {
  //  
}
​

[pito]

post # 28, error

iv_test:35:21: error: too many arguments to function 'hw_timer_t* timerBegin(uint32_t)'
   35 |   timer = timerBegin(0, 80, true);
      |           ~~~~~~~~~~^~~~~~~~~~~~~
In file included from C:\Users\Galinka\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.1.3\cores\esp32/esp32-hal.h:98,
                 from C:\Users\Galinka\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.1.3\cores\esp32/Arduino.h:45,
                 from C:\Users\Galinka\Documents\Arduino\iv_test\iv_test.ino:1:
C:\Users\Galinka\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.1.3\cores\esp32/esp32-hal-timer.h:35:13: note: declared here
   35 | hw_timer_t *timerBegin(uint32_t frequency);
      |             ^~~~~~~~~~
iv_test:37:3: error: 'timerAlarmWrite' was not declared in this scope; did you mean 'timerWrite'?
   37 |   timerAlarmWrite(timer, TIMER_US, true);
      |   ^~~~~~~~~~~~~~~
      |   timerWrite
iv_test:38:3: error: 'timerAlarmEnable' was not declared in this scope; did you mean 'timerAlarm'?
   38 |   timerAlarmEnable(timer);
      |   ^~~~~~~~~~~~~~~~
      |   timerAlarm
C:\Users\Galinka\Documents\Arduino\iv_test\iv_test.ino: At global scope:
iv_test:44:1: error: '​' does not name a type
   44 | ​
      |  
exit status 1
too many arguments to function 'hw_timer_t* timerBegin(uint32_t)'​

[ivconic]

The errors occur because the ESP32 Arduino core has changed its timer API.
Has any simple example worked for you so far?
It seems to me that you have set up the environment completely wrong.