style: updated comments

CMakeLists.txt

@@ -1 +1,6 @@
-idf_component_register(SRCS "main.c" INCLUDE_DIRS "include")
+if(${IDF_VERSION_MAJOR} STREQUAL 6)
+    set(requires esp_driver_gpio esp_driver_pcnt esp_timer)
+else()
+    set(requires driver esp_timer)
+endif()
+idf_component_register(SRCS "zh_tachometer.c" INCLUDE_DIRS "include" REQUIRES ${requires})

README.md

@@ -1,3 +1,70 @@
-# esp_component_template
+# ESP32 ESP-IDF component for tachometer (via rotary optical encoder)
 
-esp_component_template
+## 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.
+
+## Note
+
+Enable the following settings in menuconfig:
+
+```text
+PCNT_CTRL_FUNC_IN_IRAM
+PCNT_ISR_IRAM_SAF
+```
+
+## Using
+
+In an existing project, run the following command to install the components:
+
+```bash
+cd ../your_project/components
+git clone https://github.com/aZholtikov/zh_tachometer
+```
+
+In the application, add the component:
+
+```c
+#include "zh_tachometer.h"
+```
+
+## Example
+
+```c
+#include "zh_tachometer.h"
+
+static 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) {
+        ESP_LOG_ERROR("zh_tachometer", "Initialization failed: %s", esp_err_to_name(ret));
+        return;
+    }
+
+    for (;;) {
+        uint16_t rpm = 0;
+        ret = zh_tachometer_get(&tachometer_handle, &rpm);
+        if (ret == ESP_OK) {
+            printf("Tachometer value is %d rpm.\n", rpm);
+        }
+        vTaskDelay(100 / portTICK_PERIOD_MS);
+    }
+
+    zh_tachometer_deinit(&tachometer_handle);
+}
+```

idf_component.yml

@@ -0,0 +1,8 @@
+description: ESP32 ESP-IDF component for tachometer (via optical rotary encoder)
+url: https://github.com/aZholtikov/zh_tachometer
+version: "2.0.0"
+license: "Apache-2.0"
+maintainers:
+  - "Alexey Zholtikov <alexey.zholtikov@yandex.ru>"
+dependencies:
+  idf: ">=5.0"

include/zh_tachometer.h

@@ -0,0 +1,126 @@
+/**
+ * @file zh_tachometer.h
+ *
+ * @brief ESP-IDF driver for a quadrature encoder-based tachometer using PCNT
+ *        and ESP-Timer to measure rotational speed in RPM.
+ *
+ * The module leverages the ESP-IDF PCNT peripheral in quadrature decoder mode
+ * to count encoder pulses and an ESP-Timer running at 100 Hz to sample the
+ * accumulated count and compute RPM. The result is a non-blocking, RTOS-friendly
+ * interface suitable for motor speed monitoring.
+ *
+ * Key features:
+ * - Quadrature encoder support via two GPIO lines (A/B phases)
+ * - Automatic RPM calculation based on configurable pulses-per-revolution
+ * - Configurable GPIO pull-up resistors
+ * - Thread-safe access through FreeRTOS-compatible handles
+ *
+ * @note The internal PCNT unit uses accumulation mode with watch points at
+ *       ±32767. RPM values above 32767 may overflow — ensure the encoder
+ *       pulses-per-revolution and expected RPM range stay within safe bounds.
+ */
+
+#pragma once
+
+#include "math.h"
+#include "esp_log.h"
+#include "driver/gpio.h"
+#include "driver/pulse_cnt.h"
+#include "esp_timer.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#define ZH_TACHOMETER_INIT_CONFIG_DEFAULT() \
+    {                                       \
+        .a_gpio_number = GPIO_NUM_MAX,      \
+        .b_gpio_number = GPIO_NUM_MAX,      \
+        .pullup = true,                     \
+        .encoder_pulses = 0}
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /**
+     * @brief Opaque handle to the tachometer instance.
+     *
+     * Used to identify and access a specific tachometer throughout its
+     * lifetime. The internal structure is defined in the implementation
+     * file and must not be accessed directly.
+     */
+    typedef struct _zh_tachometer_handle_t zh_tachometer_handle_t;
+
+    /**
+     * @brief Initialization configuration for the quadrature encoder tachometer.
+     *
+     * This structure is passed to `zh_tachometer_init()` to configure the GPIO
+     * pins, pull-up resistors, and the encoder's pulses-per-revolution ratio.
+     *
+     * @note Both GPIO pins must be assigned before initialization.
+     *       Use GPIO_NUM_MAX to indicate an unassigned pin.
+     */
+    typedef struct
+    {
+        uint8_t a_gpio_number;   /*!< Encoder A phase GPIO number */
+        uint8_t b_gpio_number;   /*!< Encoder B phase GPIO number */
+        bool pullup;             /*!< Enable or disable GPIO pull-up resistors */
+        uint16_t encoder_pulses; /*!< Number of pulses per one full rotation */
+    } zh_tachometer_init_config_t;
+
+    /**
+     * @brief Initialize the tachometer with the provided configuration.
+     *
+     * Allocates a handle, configures the ESP-Timer (100 Hz sampling), and sets up
+     * the PCNT peripheral in quadrature decoder mode with glitch filtering.
+     *
+     * @param[in] config Pointer to the initialization configuration (must not be NULL)
+     * @param[out] handle Pointer to receive the created tachometer handle (must be NULL)
+     *
+     * @return ESP_OK on success
+     * @return ESP_ERR_INVALID_ARG if `config` or `handle` is NULL, or `encoder_pulses` is zero
+     * @return ESP_ERR_INVALID_STATE if the handle is already initialized
+     * @return ESP_ERR_NO_MEM if memory allocation fails
+     * @return ESP_FAIL if PCNT initialization or configuration failed
+     */
+    esp_err_t zh_tachometer_init(const zh_tachometer_init_config_t *config, zh_tachometer_handle_t **handle);
+
+    /**
+     * @brief Deinitialize the tachometer and release all resources.
+     *
+     * Stops the PCNT unit, removes channels and watch points, deletes the
+     * ESP-Timer, and frees the handle memory. The handle pointer is set to
+     * NULL on success.
+     *
+     * @param[in,out] handle Pointer to the tachometer handle (must not be NULL)
+     *
+     * @note After deinitialization, the handle is invalidated and must not be
+     *       used. Call zh_tachometer_init() again to reinitialize.
+     *
+     * @return ESP_OK on success
+     * @return ESP_ERR_INVALID_ARG if `handle` is NULL or `*handle` is NULL
+     * @return ESP_FAIL if PCNT stop, disable, or deletion failed
+     */
+    esp_err_t zh_tachometer_deinit(zh_tachometer_handle_t **handle);
+
+    /**
+     * @brief Retrieve the current RPM value from the tachometer.
+     *
+     * Returns the last sampled RPM value computed by the timer callback.
+     * The value represents absolute RPM (direction is discarded); negative
+     * rotation is reported as a positive value.
+     *
+     * @param[in] handle Pointer to the tachometer handle (must not be NULL)
+     * @param[out] value Pointer to receive the RPM value (must not be NULL)
+     *
+     * @return ESP_OK on success
+     * @return ESP_ERR_INVALID_ARG if `handle` or `value` is NULL
+     *
+     * @note This function is non-blocking and returns the most recent value
+     *       without accessing the PCNT peripheral directly.
+     */
+    esp_err_t zh_tachometer_get(zh_tachometer_handle_t **handle, uint16_t *value);
+
+#ifdef __cplusplus
+}
+#endif

version.txt

@@ -0,0 +1 @@
+2.0.0

zh_tachometer.c

@@ -0,0 +1,261 @@
+#include "zh_tachometer.h"
+
+#define TAG "zh_tachometer"
+
+#define ZH_LOGI(msg, ...) ESP_LOGI(TAG, msg, ##__VA_ARGS__)
+#define ZH_LOGE(msg, err, ...) ESP_LOGE(TAG, "[%s:%d:%s] " msg, __FILE__, __LINE__, esp_err_to_name(err), ##__VA_ARGS__)
+
+#define ZH_ERROR_CHECK(cond, err, cleanup, msg, ...) \
+    if (!(cond))                                     \
+    {                                                \
+        ZH_LOGE(msg, err, ##__VA_ARGS__);            \
+        cleanup;                                     \
+        return err;                                  \
+    }
+
+#define ZH_ERROR_CHECK_VOID(cond, cleanup, msg, ...) \
+    if (!(cond))                                     \
+    {                                                \
+        ZH_LOGE(msg, ESP_FAIL, ##__VA_ARGS__);       \
+        cleanup;                                     \
+        return;                                      \
+    }
+
+/**
+ * @brief Internal handle structure for the tachometer driver.
+ *
+ * Holds references to the PCNT unit and channels, the ESP-Timer used for
+ * periodic RPM sampling, the last computed RPM value, and the encoder's
+ * pulses-per-revolution configuration.
+ *
+ * @note This structure is opaque to callers and must only be accessed
+ *       through the public API functions.
+ * @warning The timer callback runs from ISR context and must not call
+ *          blocking or long-running operations.
+ */
+struct _zh_tachometer_handle_t
+{
+    pcnt_unit_handle_t pcnt_unit_handle;         /*!< PCNT unit handle for quadrature decoding */
+    pcnt_channel_handle_t pcnt_channel_a_handle; /*!< PCNT channel A handle (edge detector) */
+    pcnt_channel_handle_t pcnt_channel_b_handle; /*!< PCNT channel B handle (edge detector) */
+    esp_timer_handle_t esp_timer_handle;         /*!< ESP-Timer handle for 100 Hz RPM sampling */
+    uint16_t value;                              /*!< Last computed RPM value (absolute) */
+    uint16_t encoder_pulses;                     /*!< Pulses per one full rotation */
+};
+
+/**
+ * @brief Validate the initialization configuration.
+ *
+ * Checks that `encoder_pulses` is greater than zero.
+ *
+ * @param config Pointer to the initialization configuration
+ *
+ * @return ESP_OK on valid configuration
+ * @return ESP_ERR_INVALID_ARG if `encoder_pulses` is zero or less
+ */
+static esp_err_t _zh_tachometer_validate_config(const zh_tachometer_init_config_t *config);
+
+/**
+ * @brief Initialize the PCNT peripheral in quadrature decoder mode.
+ *
+ * Configures the PCNT unit with accumulation mode, glitch filter (1000 ns),
+ * two channels for encoder phases A and B, edge/level actions for direction
+ * counting, and watch points at ±32767. Starts the unit and clears the
+ * counter. Optionally disables GPIO pull-ups if configured.
+ *
+ * @param config Pointer to the initialization configuration
+ * @param handle Pointer to the initialized tachometer handle
+ *
+ * @return ESP_OK on successful PCNT initialization
+ * @return ESP_ERR_INVALID_ARG if GPIO numbers are invalid or identical
+ * @return ESP_FAIL on any PCNT configuration failure
+ */
+static esp_err_t _zh_tachometer_pcnt_init(const zh_tachometer_init_config_t *config, zh_tachometer_handle_t *handle);
+
+/**
+ * @brief Initialize the ESP-Timer for periodic RPM sampling.
+ *
+ * Creates a periodic timer that fires every 10 ms (100 Hz) and invokes
+ * the alarm callback to read and convert the PCNT count to RPM.
+ *
+ * @param handle Pointer to the initialized tachometer handle
+ *
+ * @return ESP_OK on successful timer initialization
+ * @return ESP_FAIL on timer creation or start failure
+ */
+static esp_err_t _zh_tachometer_timer_init(zh_tachometer_handle_t *handle);
+
+/**
+ * @brief ESP-Timer alarm callback for RPM sampling.
+ *
+ * Executed every 10 ms from ISR context. Reads the accumulated PCNT count,
+ * clears it, and converts it to RPM using the formula:
+ *
+ *     RPM = (count * 100.0 / pulses_per_rev) * 60
+ *
+ * The result is stored as an absolute value (direction discarded).
+ *
+ * @param arg Pointer to the tachometer handle
+ */
+static void _zh_tachometer_timer_on_alarm_cb(void *arg);
+
+esp_err_t zh_tachometer_init(const zh_tachometer_init_config_t *config, zh_tachometer_handle_t **handle)
+{
+    ZH_LOGI("Tachometer initialization started.");
+    ZH_ERROR_CHECK(config != NULL && handle != NULL, ESP_ERR_INVALID_ARG, NULL, "Tachometer initialization failed. Invalid argument.");
+    ZH_ERROR_CHECK(*handle == NULL, ESP_ERR_INVALID_STATE, NULL, "Tachometer initialization failed. Tachometer is already initialized.");
+    ZH_ERROR_CHECK(_zh_tachometer_validate_config(config) == ESP_OK, ESP_FAIL, NULL, "Tachometer initialization failed. Initial configuration check failed.");
+    *handle = heap_caps_calloc(1, sizeof(zh_tachometer_handle_t), MALLOC_CAP_8BIT);
+    ZH_ERROR_CHECK(*handle != NULL, ESP_ERR_NO_MEM, NULL, "Tachometer initialization failed. Failed to allocate tachometer handle.");
+    ZH_ERROR_CHECK(_zh_tachometer_timer_init(*handle) == ESP_OK, ESP_FAIL, heap_caps_free(*handle); *handle = NULL, "Tachometer initialization failed. Timer initialization failed.");
+    ZH_ERROR_CHECK(_zh_tachometer_pcnt_init(config, *handle) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(esp_timer_stop((*handle)->esp_timer_handle) == ESP_OK, ESP_FAIL, NULL, "Timer stop fail.")};
+                   {ZH_ERROR_CHECK(esp_timer_delete((*handle)->esp_timer_handle) == ESP_OK, ESP_FAIL, NULL, "Timer delete fail.")};
+                   heap_caps_free(*handle); *handle = NULL, "Tachometer initialization failed. PCNT initialization failed.");
+    (*handle)->encoder_pulses = config->encoder_pulses;
+    ZH_LOGI("Tachometer initialization completed successfully.");
+    return ESP_OK;
+}
+
+esp_err_t zh_tachometer_deinit(zh_tachometer_handle_t **handle)
+{
+    ZH_LOGI("Tachometer deinitialization started.");
+    ZH_ERROR_CHECK(handle != NULL && *handle != NULL, ESP_ERR_INVALID_ARG, NULL, "Tachometer deinitialization failed. Invalid argument.");
+    ZH_ERROR_CHECK(pcnt_unit_stop((*handle)->pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT unit stop fail.");
+    ZH_ERROR_CHECK(pcnt_unit_disable((*handle)->pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT unit disable fail.");
+    ZH_ERROR_CHECK(pcnt_unit_remove_watch_point((*handle)->pcnt_unit_handle, 32767) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT unit remove watch point fail.");
+    ZH_ERROR_CHECK(pcnt_unit_remove_watch_point((*handle)->pcnt_unit_handle, -32767) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT unit remove watch point fail.");
+    ZH_ERROR_CHECK(pcnt_del_channel((*handle)->pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT delete channel fail.");
+    ZH_ERROR_CHECK(pcnt_del_channel((*handle)->pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT delete channel fail.");
+    ZH_ERROR_CHECK(pcnt_del_unit((*handle)->pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. PCNT delete unit fail.");
+    ZH_ERROR_CHECK(esp_timer_stop((*handle)->esp_timer_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. Timer stop fail.");
+    ZH_ERROR_CHECK(esp_timer_delete((*handle)->esp_timer_handle) == ESP_OK, ESP_FAIL, NULL, "Tachometer deinitialization failed. Timer delete fail.");
+    heap_caps_free(*handle);
+    *handle = NULL;
+    ZH_LOGI("Tachometer deinitialization completed successfully.");
+    return ESP_OK;
+}
+
+esp_err_t zh_tachometer_get(zh_tachometer_handle_t **handle, uint16_t *value)
+{
+    ZH_LOGI("Tachometer get position started.");
+    ZH_ERROR_CHECK(handle != NULL && *handle != NULL && value != NULL, ESP_ERR_INVALID_ARG, NULL, "Tachometer get position failed. Invalid argument.");
+    *value = (*handle)->value;
+    ZH_LOGI("Tachometer get position completed successfully.");
+    return ESP_OK;
+}
+
+static esp_err_t _zh_tachometer_validate_config(const zh_tachometer_init_config_t *config)
+{
+    ZH_ERROR_CHECK(config->encoder_pulses > 0, ESP_ERR_INVALID_ARG, NULL, "Invalid encoder pulses.");
+    return ESP_OK;
+}
+
+static esp_err_t _zh_tachometer_pcnt_init(const zh_tachometer_init_config_t *config, zh_tachometer_handle_t *handle)
+{
+    ZH_ERROR_CHECK(config->a_gpio_number < GPIO_NUM_MAX && config->b_gpio_number < GPIO_NUM_MAX, ESP_ERR_INVALID_ARG, NULL, "Invalid GPIO number.")
+    ZH_ERROR_CHECK(config->a_gpio_number != config->b_gpio_number, ESP_ERR_INVALID_ARG, NULL, "Encoder A and B GPIO is same.")
+    pcnt_unit_config_t pcnt_unit_config = {
+        .high_limit = 32767,
+        .low_limit = -32767,
+        .flags.accum_count = true,
+    };
+    pcnt_unit_handle_t pcnt_unit_handle = NULL;
+    ZH_ERROR_CHECK(pcnt_new_unit(&pcnt_unit_config, &pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT initialization failed.");
+    pcnt_glitch_filter_config_t pcnt_glitch_filter_config = {
+        .max_glitch_ns = 1000,
+    };
+    ZH_ERROR_CHECK(pcnt_unit_set_glitch_filter(pcnt_unit_handle, &pcnt_glitch_filter_config) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    pcnt_chan_config_t pcnt_chan_a_config = {
+        .edge_gpio_num = config->a_gpio_number,
+        .level_gpio_num = config->b_gpio_number,
+    };
+    pcnt_channel_handle_t pcnt_channel_a_handle = NULL;
+    ZH_ERROR_CHECK(pcnt_new_channel(pcnt_unit_handle, &pcnt_chan_a_config, &pcnt_channel_a_handle) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    pcnt_chan_config_t pcnt_chan_b_config = {
+        .edge_gpio_num = config->b_gpio_number,
+        .level_gpio_num = config->a_gpio_number,
+    };
+    pcnt_channel_handle_t pcnt_channel_b_handle = NULL;
+    ZH_ERROR_CHECK(pcnt_new_channel(pcnt_unit_handle, &pcnt_chan_b_config, &pcnt_channel_b_handle) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_channel_set_edge_action(pcnt_channel_a_handle, PCNT_CHANNEL_EDGE_ACTION_DECREASE, PCNT_CHANNEL_EDGE_ACTION_HOLD) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_channel_set_level_action(pcnt_channel_a_handle, PCNT_CHANNEL_LEVEL_ACTION_KEEP, PCNT_CHANNEL_LEVEL_ACTION_HOLD) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_channel_set_edge_action(pcnt_channel_b_handle, PCNT_CHANNEL_EDGE_ACTION_INCREASE, PCNT_CHANNEL_EDGE_ACTION_HOLD) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_channel_set_level_action(pcnt_channel_b_handle, PCNT_CHANNEL_LEVEL_ACTION_KEEP, PCNT_CHANNEL_LEVEL_ACTION_HOLD) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_unit_add_watch_point(pcnt_unit_handle, 32767) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_unit_add_watch_point(pcnt_unit_handle, -32767) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, 32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_unit_enable(pcnt_unit_handle) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, 32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, -32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_unit_clear_count(pcnt_unit_handle) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_unit_disable(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT unit disable fail.")};
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, 32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, -32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    ZH_ERROR_CHECK(pcnt_unit_start(pcnt_unit_handle) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(pcnt_unit_disable(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT unit disable fail.")};
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, 32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_unit_remove_watch_point(pcnt_unit_handle, -32767) == ESP_OK, ESP_FAIL, NULL, "PCNT unit remove watch point fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_a_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_channel(pcnt_channel_b_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete channel fail.")};
+                   {ZH_ERROR_CHECK(pcnt_del_unit(pcnt_unit_handle) == ESP_OK, ESP_FAIL, NULL, "PCNT delete unit fail.")}, "PCNT initialization failed.");
+    if (config->pullup == false)
+    {
+        ZH_ERROR_CHECK(gpio_pullup_dis((gpio_num_t)config->a_gpio_number) == ESP_OK, ESP_FAIL, NULL, "GPIO pullup disable fail.");
+        ZH_ERROR_CHECK(gpio_pullup_dis((gpio_num_t)config->b_gpio_number) == ESP_OK, ESP_FAIL, NULL, "GPIO pullup disable fail.");
+    }
+    handle->pcnt_unit_handle = pcnt_unit_handle;
+    handle->pcnt_channel_a_handle = pcnt_channel_a_handle;
+    handle->pcnt_channel_b_handle = pcnt_channel_b_handle;
+    return ESP_OK;
+}
+
+static esp_err_t _zh_tachometer_timer_init(zh_tachometer_handle_t *handle)
+{
+    const esp_timer_create_args_t timer_args = {
+        .callback = &_zh_tachometer_timer_on_alarm_cb,
+        .arg = handle,
+    };
+    ZH_ERROR_CHECK(esp_timer_create(&timer_args, &handle->esp_timer_handle) == ESP_OK, ESP_FAIL, NULL, "Timer initialization failed.");
+    ZH_ERROR_CHECK(esp_timer_start_periodic(handle->esp_timer_handle, 10000) == ESP_OK, ESP_FAIL,
+                   {ZH_ERROR_CHECK(esp_timer_delete(handle->esp_timer_handle) == ESP_OK, ESP_FAIL, NULL, "Timer delete fail.")}, "Timer initialization failed.");
+    return ESP_OK;
+}
+
+static void IRAM_ATTR _zh_tachometer_timer_on_alarm_cb(void *arg)
+{
+    zh_tachometer_handle_t *handle = (zh_tachometer_handle_t *)arg;
+    int pcnt_count = 0;
+    ZH_ERROR_CHECK_VOID(pcnt_unit_get_count(handle->pcnt_unit_handle, &pcnt_count) == ESP_OK, NULL, "PCNT internal error.");
+    ZH_ERROR_CHECK_VOID(pcnt_unit_clear_count(handle->pcnt_unit_handle) == ESP_OK, NULL, "PCNT internal error.");
+    float value_temp = ((pcnt_count * 100.0) / handle->encoder_pulses) * 60;
+    handle->value = (uint16_t)fabs(value_temp);
+}