MTGcompanion/main/buzzer.c

/*
 * MTG RFID Companion - Piezo buzzer driver (LEDC PWM)
 */

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "driver/ledc.h"
#include "hw_pins.h"
#include "buzzer.h"

#include "freertos/queue.h"

static const char *TAG = "buzzer";

#define BUZZER_SPEED_MODE LEDC_LOW_SPEED_MODE
#define BUZZER_TIMER_NUM  LEDC_TIMER_0
#define BUZZER_CHANNEL    LEDC_CHANNEL_0

static QueueHandle_t s_sound_queue = NULL;
static volatile bool s_melody_playing = false;

static const buzzer_note_t MELODY_VICTORY[] = {
    {NOTE_C5, 90}, {NOTE_C5, 90}, {NOTE_C5, 90}, {NOTE_C5, 220},
    {NOTE_GS4, 220}, {NOTE_AS4, 220}, {NOTE_C5, 140}, {NOTE_REST, 35},
    {NOTE_AS4, 90}, {NOTE_C5, 400}
};

static const buzzer_note_t MELODY_LEGENDARY[] = {
    {NOTE_G4, 65}, {NOTE_C5, 65}, {NOTE_E5, 65}, {NOTE_G5, 90}, {NOTE_C6, 280}
};

static const buzzer_note_t MELODY_LOSS[] = {
    {NOTE_D4, 130}, {NOTE_CS4, 130}, {NOTE_C4, 130}, {NOTE_B3, 260},
    {NOTE_REST, 35}, {NOTE_AS3, 400}
};

esp_err_t buzzer_play_notes(const buzzer_note_t *notes, size_t count)
{
    if (notes == NULL || count == 0) return ESP_OK;
    for (size_t i = 0; i < count; i++) {
        if (notes[i].freq_hz > 0) {
            buzzer_start(notes[i].freq_hz, 30);
            vTaskDelay(pdMS_TO_TICKS(notes[i].duration_ms));
            buzzer_stop();
        } else {
            vTaskDelay(pdMS_TO_TICKS(notes[i].duration_ms));
        }
        /* 12ms articulation gap between notes for distinct 8-bit chiptune feel */
        vTaskDelay(pdMS_TO_TICKS(12));
    }
    return ESP_OK;
}

static void buzzer_task(void *arg)
{
    (void)arg;
    buzzer_sound_t sound;
    while (1) {
        if (xQueueReceive(s_sound_queue, &sound, portMAX_DELAY) == pdTRUE) {
            s_melody_playing = true;
            switch (sound) {
            case BUZZER_SOUND_VICTORY:
                buzzer_play_notes(MELODY_VICTORY, sizeof(MELODY_VICTORY) / sizeof(MELODY_VICTORY[0]));
                break;
            case BUZZER_SOUND_LEGENDARY:
                buzzer_play_notes(MELODY_LEGENDARY, sizeof(MELODY_LEGENDARY) / sizeof(MELODY_LEGENDARY[0]));
                break;
            case BUZZER_SOUND_LOSS:
                buzzer_play_notes(MELODY_LOSS, sizeof(MELODY_LOSS) / sizeof(MELODY_LOSS[0]));
                break;
            default:
                break;
            }
            s_melody_playing = false;
        }
    }
}

esp_err_t buzzer_init(void)
{
    ledc_timer_config_t timer_cfg = {
        .speed_mode = BUZZER_SPEED_MODE,
        .timer_num = BUZZER_TIMER_NUM,
        .duty_resolution = LEDC_TIMER_13_BIT,
        .freq_hz = 2000,
        .clk_cfg = LEDC_AUTO_CLK,
    };
    esp_err_t ret = ledc_timer_config(&timer_cfg);
    if (ret != ESP_OK) {
        return ret;
    }

    ledc_channel_config_t chan_cfg = {
        .gpio_num = HW_BUZZER_GPIO,
        .speed_mode = BUZZER_SPEED_MODE,
        .channel = BUZZER_CHANNEL,
        .timer_sel = BUZZER_TIMER_NUM,
        .duty = 0,
        .hpoint = 0,
    };
    ret = ledc_channel_config(&chan_cfg);
    if (ret != ESP_OK) {
        return ret;
    }

    if (s_sound_queue == NULL) {
        s_sound_queue = xQueueCreate(4, sizeof(buzzer_sound_t));
        xTaskCreate(buzzer_task, "buzzer_task", 2048, NULL, 3, NULL);
    }

    ESP_LOGI(TAG, "buzzer ready on GPIO %d (chiptune synth active)", HW_BUZZER_GPIO);
    return ESP_OK;
}

esp_err_t buzzer_start(uint32_t freq_hz, uint32_t duty_percent)
{
    if (freq_hz == 0) {
        return buzzer_stop();
    }
    uint32_t duty = ((uint32_t)1 << 13) * duty_percent / 100u;
    if (duty_percent >= 100) {
        duty = ((uint32_t)1 << 13);
    }

    esp_err_t ret = ledc_set_freq(BUZZER_SPEED_MODE, BUZZER_TIMER_NUM, freq_hz);
    if (ret != ESP_OK) {
        return ret;
    }
    ret = ledc_set_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL, duty);
    if (ret != ESP_OK) {
        return ret;
    }
    return ledc_update_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL);
}

esp_err_t buzzer_stop(void)
{
    ledc_set_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL, 0);
    return ledc_update_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL);
}

esp_err_t buzzer_chirp(uint32_t freq_hz, uint32_t duration_ms)
{
    if (s_melody_playing) {
        return ESP_OK; /* Don't disrupt ongoing background chiptune melody */
    }
    esp_err_t ret = buzzer_start(freq_hz, 30);
    if (ret != ESP_OK) {
        return ret;
    }
    vTaskDelay(pdMS_TO_TICKS(duration_ms));
    return buzzer_stop();
}

esp_err_t buzzer_play_sound(buzzer_sound_t sound)
{
    if (s_sound_queue != NULL) {
        xQueueSend(s_sound_queue, &sound, 0);
    }
    return ESP_OK;
}