feat(sensors): Add AHT30 sensor driver

Author: PetrESP

.github/workflows/upload_component.yml

@@ -103,6 +103,7 @@ jobs:
             components/io_expander/esp_io_expander_ht8574
             components/io_expander/esp_io_expander_pi4ioe5v6408
             components/sensors/icm42670
+            components/sensors/aht30
           namespace: "espressif"
           api_token: ${{ secrets.IDF_COMPONENT_API_TOKEN }}
           dry_run: ${{ github.ref_name != 'master' || github.repository_owner != 'espressif' }}

components/.build-test-rules.yml

@@ -41,6 +41,13 @@ components/sensors/icm42670:
     - if: IDF_VERSION < "5.2.0"
       reason: Requires I2C Driver-NG which was introduced in v5.2
 
+components/sensors/aht30:
+  depends_filepatterns:
+    - "components/sensors/aht30/**"
+  disable:
+    - if: IDF_VERSION < "5.2.0"
+      reason: Requires I2C Driver-NG which was introduced in v5.2
+
 components/qma6100p:
   depends_filepatterns:
     - "components/qma6100p/**"

components/sensors/aht30/CMakeLists.txt

@@ -0,0 +1,10 @@
+if("${IDF_VERSION_MAJOR}.${IDF_VERSION_MINOR}" VERSION_GREATER_EQUAL "5.3")
+    set(REQ esp_driver_i2c)
+else()
+    set(REQ driver)
+endif()
+
+idf_component_register(SRCS "aht30.c"
+                    INCLUDE_DIRS "include" REQUIRES ${REQ})
+
+target_link_libraries(${COMPONENT_LIB} INTERFACE "-u aht30_impl_init")

components/sensors/aht30/README.md

@@ -0,0 +1,24 @@
+# AHT30 Temperature and  humidity sensor
+
+[![Component Registry](https://components.espressif.com/components/espressif/aht30/badge.svg)](https://components.espressif.com/components/espressif/aht30)
+![maintenance-status](https://img.shields.io/badge/maintenance-passively--maintained-yellowgreen.svg)
+
+C driver for Asair AHT30 temperature and humidity sensor.
+
+## Features
+
+- Get temperature and humidity readings as float values.
+- Check measurement status.
+
+## Get Started
+
+This driver, along with many other components from this repository, can be used as a package from [Espressif's IDF Component Registry](https://components.espressif.com). To include this driver in your project, run the following idf.py from the project's root directory:
+
+```
+    idf.py add-dependency "espressif/icm42670==*"
+```
+
+Another option is to manually create a `idf_component.yml` file. You can find more about using .yml files for components from [Espressif's documentation](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/tools/idf-component-manager.html).
+
+## See Also
+* [AHT30 product page](https://asairsensors.com/product/aht30-integrated-temperature-and-humidity-sensor/)

components/sensors/aht30/aht30.c

@@ -0,0 +1,230 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+#include "esp_check.h"
+#include "iot_sensor_hub.h"
+#include "aht30.h"
+
+#define I2C_CLK_SPEED 400000
+
+/*******************************************************************************
+* Types definitions
+*******************************************************************************/
+
+typedef struct {
+    i2c_master_dev_handle_t i2c_handle;
+} aht30_dev_t;
+
+/*******************************************************************************
+* Function definitions
+*******************************************************************************/
+static esp_err_t aht30_write(aht30_handle_t sensor, const uint8_t *data_buf, const uint8_t data_len);
+static esp_err_t aht30_receive(const aht30_handle_t sensor, uint8_t *data_buf, const uint8_t data_len);
+static uint8_t aht30_calc_crc(uint8_t *data, uint8_t length);
+
+/*******************************************************************************
+* Local variables
+*******************************************************************************/
+static const char *TAG = "AHT30";
+
+/*******************************************************************************
+* Public API functions
+*******************************************************************************/
+
+esp_err_t aht30_create(i2c_master_bus_handle_t i2c_bus, const uint8_t dev_addr, aht30_handle_t *handle_ret)
+{
+    ESP_RETURN_ON_FALSE(i2c_bus != NULL, ESP_ERR_INVALID_ARG, TAG, "I2C handle can't be NULL");
+    ESP_RETURN_ON_FALSE(handle_ret != NULL, ESP_ERR_INVALID_ARG, TAG, "AHT30 handle can't be NULL");
+
+    esp_err_t ret = ESP_OK;
+
+    // Allocate memory and initialize the driver object
+    aht30_dev_t *sensor = (aht30_dev_t *) calloc(1, sizeof(aht30_dev_t));
+    ESP_RETURN_ON_FALSE(sensor != NULL, ESP_ERR_NO_MEM, TAG, "Not enough memory");
+
+    const i2c_device_config_t i2c_dev_cfg = {
+        .device_address = dev_addr,
+        .scl_speed_hz = I2C_CLK_SPEED,
+    };
+
+    ret = i2c_master_bus_add_device(i2c_bus, &i2c_dev_cfg, &sensor->i2c_handle);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to add a new I2C device");
+        aht30_delete(sensor);
+        return ret;
+    }
+    assert(sensor->i2c_handle);
+
+    ESP_LOGD(TAG, "Successfully created a AHT30 device");
+    *handle_ret = sensor;
+    return ret;
+}
+
+void aht30_delete(aht30_handle_t sensor)
+{
+    aht30_dev_t *sens = (aht30_dev_t *) sensor;
+
+    if (sens->i2c_handle) {
+        i2c_master_bus_rm_device(sens->i2c_handle);
+    }
+
+    free(sens);
+}
+
+esp_err_t aht30_get_temperature_humidity_value(aht30_handle_t sensor, float *temperature, float *humidity)
+{
+    ESP_RETURN_ON_FALSE(sensor != NULL, ESP_ERR_INVALID_ARG, TAG, "AHT30 handle can't be NULL");
+    ESP_RETURN_ON_FALSE(temperature != NULL, ESP_ERR_INVALID_ARG, TAG, "Pointer to the busy variable can't be NULL");
+    ESP_RETURN_ON_FALSE(humidity != NULL, ESP_ERR_INVALID_ARG, TAG, "Pointer to the busy variable can't be NULL");
+
+    esp_err_t ret = ESP_OK;
+
+    // Start measurement command specified by the manufacturer
+    uint8_t start_measurement[] = {0xAC, 0x33, 0x00};
+
+    ret = aht30_write(sensor, start_measurement, sizeof(start_measurement));
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to start AHT30 measurement");
+        return ret;
+    }
+
+    bool busy;
+    uint8_t max_tries = 18;
+    // Wait for the measurement to finish
+    do {
+        ret = aht30_get_busy(sensor, &busy);
+        if (ret != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to read AHT30 busy status");
+            return ret;
+        }
+        vTaskDelay(pdMS_TO_TICKS(10));
+    } while (--max_tries && busy);
+
+    if (busy) {
+        ESP_LOGE(TAG, "AHT30 timeout of measurement");
+        return ESP_FAIL;
+    }
+
+    uint8_t crc_result;
+    uint8_t receive_buf[7];
+    ESP_RETURN_ON_ERROR(aht30_receive(sensor, receive_buf, sizeof(receive_buf)), TAG, "Failed to receive measurement data");
+
+    crc_result = aht30_calc_crc(receive_buf, sizeof(receive_buf) - 1);
+    ESP_RETURN_ON_FALSE(crc_result == receive_buf[sizeof(receive_buf) - 1], ESP_FAIL, TAG,
+                        "Result of CRC calculation does not match");
+
+    uint32_t raw_value;
+    raw_value = (receive_buf[3] & 0x0F) << 16 | receive_buf[4] << 8 | receive_buf[5];
+    *temperature = (float)raw_value * 200 / (1 << 20) - 50;
+
+    raw_value = receive_buf[1] << 12 | receive_buf[2] << 4 | receive_buf[3] >> 4;
+    *humidity = (float)raw_value * 100 / (1 << 20) ;
+
+    return ret;
+}
+
+esp_err_t aht30_get_busy(aht30_handle_t sensor, bool *busy)
+{
+    ESP_RETURN_ON_FALSE(sensor != NULL, ESP_ERR_INVALID_ARG, TAG, "AHT30 handle can't be NULL");
+    ESP_RETURN_ON_FALSE(busy != NULL, ESP_ERR_INVALID_ARG, TAG, "Pointer to the busy variable can't be NULL");
+    uint8_t data = 0;
+
+    ESP_RETURN_ON_ERROR(aht30_receive(sensor, &data, 1), TAG, "Read sensor busy failed");
+
+    *busy = (data & BIT7);
+    return ESP_OK;
+}
+
+/*******************************************************************************
+* Private functions
+*******************************************************************************/
+static esp_err_t aht30_write(const aht30_handle_t sensor, const uint8_t *data_buf, const uint8_t data_len)
+{
+    aht30_dev_t *sens = (aht30_dev_t *) sensor;
+    assert(sens);
+
+    return i2c_master_transmit(sens->i2c_handle, data_buf, data_len, -1);
+}
+
+static esp_err_t aht30_receive(const aht30_handle_t sensor, uint8_t *data_buf, const uint8_t data_len)
+{
+    aht30_dev_t *sens = (aht30_dev_t *) sensor;
+    assert(sens);
+
+    return i2c_master_receive(sens->i2c_handle, data_buf, data_len, -1);
+}
+
+static uint8_t aht30_calc_crc(uint8_t *data, uint8_t length)
+{
+    uint8_t i;
+    uint8_t byte;
+    uint8_t crc = 0xFF;
+    for (byte = 0; byte < length; byte++) {
+        crc ^= (data[byte]);
+        for (i = 8; i > 0; --i) {
+            if (crc & 0x80) {
+                crc = (crc << 1) ^ 0x31;
+            } else {
+                crc = (crc << 1);
+            }
+        }
+    }
+    return crc;
+}
+
+/*******************************************************************************
+* Private functions for sensor hub implementation
+*******************************************************************************/
+
+static aht30_handle_t sensor_hub_aht30_handle;
+
+esp_err_t aht30_impl_init(bus_handle_t bus_handle, uint8_t addr)
+{
+    esp_err_t ret;
+
+    ret = aht30_create(bus_handle, addr, &sensor_hub_aht30_handle);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to create AHT30 with error %s", esp_err_to_name(ret));
+    }
+
+    return ret;
+}
+
+esp_err_t aht30_impl_deinit(void)
+{
+    aht30_delete(sensor_hub_aht30_handle);
+    sensor_hub_aht30_handle = NULL;
+    return ESP_OK;
+}
+
+esp_err_t aht30_impl_test(void)
+{
+    bool busy;
+    return aht30_get_busy(sensor_hub_aht30_handle, &busy);
+}
+
+esp_err_t aht30_impl_acquire_humidity(float *humidity)
+{
+    float temperature;
+    return aht30_get_temperature_humidity_value(sensor_hub_aht30_handle, &temperature, humidity);
+}
+
+esp_err_t aht30_impl_acquire_temperature(float *temperature)
+{
+    float humidity;
+    return aht30_get_temperature_humidity_value(sensor_hub_aht30_handle, temperature, &humidity);
+}
+
+static humiture_impl_t aht30_impl = {
+    .init = aht30_impl_init,
+    .deinit = aht30_impl_deinit,
+    .test = aht30_impl_test,
+    .acquire_humidity = aht30_impl_acquire_humidity,
+    .acquire_temperature = aht30_impl_acquire_temperature,
+};
+
+SENSOR_HUB_DETECT_FN(HUMITURE_ID, sensor_hub_aht30, &aht30_impl);

components/sensors/aht30/idf_component.yml

@@ -0,0 +1,8 @@
+version: 1.0.0
+description: I2C driver for ATH30 temperature and humidity sensor
+url: https://github.com/espressif/esp-bsp/tree/master/components/aht30
+dependencies:
+  idf: ">=5.2"
+  sensor_hub:
+    version: ^0.1.4
+    public: true

components/sensors/aht30/include/aht30.h

@@ -0,0 +1,67 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "driver/i2c_master.h"
+
+#define AHT30_I2C_ADDRESS         0x38
+
+typedef void *aht30_handle_t;
+
+/**
+ * @brief Create and init sensor object
+ *
+ * @param[in]  i2c_bus    I2C bus handle. Obtained from i2c_new_master_bus()
+ * @param[in]  dev_addr   I2C device address of sensor.
+ * @param[out] handle_ret Handle to created AHT30 driver object
+ *
+ * @return
+ *     - ESP_OK Success
+ *     - ESP_ERR_NO_MEM Not enough memory for the driver
+ *     - Others Error from underlying I2C driver
+ */
+esp_err_t aht30_create(i2c_master_bus_handle_t i2c_bus, const uint8_t dev_addr, aht30_handle_t *handle_ret);
+
+/**
+ * @brief Delete and release a sensor object
+ *
+ * @param sensor object handle of AHT30
+ */
+void aht30_delete(aht30_handle_t sensor);
+
+/**
+ * @brief Read temperature and humidity values
+ *
+ * @param sensor        object handle of AHT30
+ * @param temperature   temperature measurement
+ * @param humidity      humidity measurement
+ *
+ * @return
+ *     - ESP_OK Success
+ *     - ESP_FAIL Fail
+ */
+esp_err_t aht30_get_temperature_humidity_value(aht30_handle_t sensor, float *temperature, float *humidity);
+
+/**
+ * @brief Read busy status
+ *
+ * @param sensor    object handle of AHT30
+ * @param busy      busy status
+ *
+ * @return
+ *     - ESP_OK Success
+ *     - ESP_FAIL Fail
+ */
+esp_err_t aht30_get_busy(aht30_handle_t sensor, bool *busy);
+
+#ifdef __cplusplus
+}
+#endif