ESP32 - Example setting a clock signal (50% duty cycle) on a pin.

SetClockOnPin.ino

#include "driver/ledc.h"

static void enable_out_clock(uint8_t pin,double freq) {
    periph_module_enable(PERIPH_LEDC_MODULE);
    ledc_timer_bit_t bit_num = (ledc_timer_bit_t) 1;      // 3 normally
    int duty = pow(2, (int) bit_num) / 2;

    ledc_timer_config_t timer_conf;
    timer_conf.bit_num = bit_num;
    timer_conf.freq_hz = freq;
    timer_conf.speed_mode = LEDC_HIGH_SPEED_MODE;
    timer_conf.timer_num = LEDC_TIMER_0;
    esp_err_t err = ledc_timer_config(&timer_conf);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "ledc_timer_config failed, rc=%x", err);
    }

    ledc_channel_config_t ch_conf;
    ch_conf.channel = LEDC_CHANNEL_0;
    ch_conf.timer_sel = LEDC_TIMER_0;
    ch_conf.intr_type = LEDC_INTR_DISABLE;
    ch_conf.duty = duty;
    ch_conf.speed_mode = LEDC_HIGH_SPEED_MODE;
    ch_conf.gpio_num = pin; //s_config.pin_xclk; 
    err = ledc_channel_config(&ch_conf);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "ledc_channel_config failed, rc=%x", err);
    }

    // Set the PWM to the duty specified
   ledc_set_duty(LEDC_HIGH_SPEED_MODE, LEDC_CHANNEL_0, duty);
   ledc_update_duty(LEDC_HIGH_SPEED_MODE, LEDC_CHANNEL_0);
}