ESP32 ESP-IDF component for tachometer (via rotary optical encoder)

Features

1. Quadrature encoder support via ESP-IDF PCNT peripheral in quadrature decoder mode.
2. Automatic RPM calculation based on configurable pulses-per-revolution.
3. Periodic RPM sampling via ESP-Timer at 100 Hz (10 ms interval).
4. Configurable GPIO pull-up resistors for encoder A/B phases.
5. PCNT glitch filter (1000 ns) to reject spurious transitions.
6. Watch points at ±32767 for overflow detection.
7. Multiple tachometers supported — each requires its own PCNT unit and timer.

Using

In an existing project, run the following command to install the component:

cd ../your_project/components
git clone https://github.com/aZholtikov/zh_tachometer

In the application, add the component:

#include "zh_tachometer.h"

Examples

Basic Example

#include "zh_tachometer.h"

zh_tachometer_handle_t *tachometer_handle = NULL;

void app_main(void)
{
    esp_log_level_set("zh_tachometer", ESP_LOG_ERROR);
    zh_tachometer_init_config_t config = ZH_TACHOMETER_INIT_CONFIG_DEFAULT();
    config.a_gpio_number = GPIO_NUM_26;
    config.b_gpio_number = GPIO_NUM_27;
    config.encoder_pulses = 3600;
    esp_err_t ret = zh_tachometer_init(&config, &tachometer_handle);
    if (ret != ESP_OK)
    {
        printf("Tachometer initialization error\n");
        return;
    }
    for (;;)
    {
        uint16_t value = 0;
        ret = zh_tachometer_get(&tachometer_handle, &value);
        if (ret == ESP_OK)
        {
            printf("Tachometer value is %u rpm.\n", value);
        }
        vTaskDelay(100 / portTICK_PERIOD_MS);
    }
    zh_tachometer_deinit(&tachometer_handle);
}