esp-pwm/main/buzzer.c

#include <math.h>
#include <stdint.h>

#include "driver/ledc.h"
#include "esp_clk_tree.h"
#include "esp_err.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h" // IWYU pragma: keep
#include "freertos/task.h"
#include "hal/ledc_types.h"
#include "soc/clk_tree_defs.h"

#include "buzzer.h"

static const char* TAG = "BUZZER_C";

const uint32_t init_buzzer_freq = 2731;

void buzzer_init(const uint32_t frequency) {
    uint32_t clk_freq = 0;
    ESP_ERROR_CHECK(esp_clk_tree_src_get_freq_hz(
        SOC_MOD_CLK_RC_FAST, ESP_CLK_TREE_SRC_FREQ_PRECISION_EXACT, &clk_freq));

    uint32_t duty_resolution =
        ledc_find_suitable_duty_resolution(clk_freq, frequency);
    if (duty_resolution == 0) {
        ESP_LOGE(TAG, "Could not determine optimal duty resolution.\n");
        return;
    }

    ledc_timer_config_t ledc_config = {.speed_mode = LEDC_LOW_SPEED_MODE,
                                       .timer_num = LEDC_TIMER_0,
                                       .freq_hz = frequency,
                                       .duty_resolution = duty_resolution,
                                       .clk_cfg = LEDC_USE_RC_FAST_CLK};

    ESP_ERROR_CHECK(ledc_timer_config(&ledc_config));

    ledc_channel_config_t ledc_ch_config = {
        .gpio_num = 9,
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .channel = LEDC_CHANNEL_0,
        .timer_sel = LEDC_TIMER_0,
        .duty = (uint32_t)(pow(2, duty_resolution) / 2),
        // .hpoint = ((uint32_t) pow(2, duty_resolution)) - 1,
        .hpoint = 0,
        .sleep_mode = LEDC_SLEEP_MODE_KEEP_ALIVE,
        .flags.output_invert = false};

    ESP_ERROR_CHECK(ledc_channel_config(&ledc_ch_config));
}

uint32_t modify_frequency(int amount) {
    uint32_t freq = ledc_get_freq(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0) + amount;
    if (freq < 10) {
        freq = 10;
    }
    buzzer_pause();
    ESP_ERROR_CHECK(ledc_set_freq(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0, freq));
    buzzer_resume();
    return freq;
}

uint32_t reset_frequency() {
    ESP_ERROR_CHECK(
        ledc_set_freq(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0, init_buzzer_freq));
    return init_buzzer_freq;
}

void set_frequency(const uint32_t freq) {
    ESP_ERROR_CHECK(ledc_set_freq(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0, freq));
}

void buzzer_pause() {
    ESP_ERROR_CHECK(ledc_timer_pause(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0));
}

void buzzer_reset() {
    ESP_ERROR_CHECK(ledc_timer_rst(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0));
}

void buzzer_resume() {
    ESP_ERROR_CHECK(ledc_timer_resume(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0));
}