ESP32 HTE501 Temperature and Humidity Sensor

Code Examples

Below you can find code examples of HTE501 Temperature and Humidity Sensor with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO

If you encounter issues while using the HTE501 Temperature and Humidity Sensor, check the Common Issues Troubleshooting Guide.

ESP32 HTE501 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the HTE501 Temperature and Humidity Sensor:

#include <Wire.h>
#include <Adafruit_SHT31.h> // Adafruit library compatible with I2C humidity/temp sensors

Adafruit_SHT31 sht31 = Adafruit_SHT31();

void setup() {
  Serial.begin(115200);        // Start the serial communication
  Wire.begin();                // Initialize I2C

  // Initialize the sensor
  if (!sht31.begin(0x44)) {    // The default I2C address for many SHT3x sensors is 0x44
    Serial.println("Couldn't find HTE501 sensor!");
    while (1) delay(1);        // Stop if the sensor is not found
  }
  Serial.println("HTE501 Sensor initialized.");
}

void loop() {
  float temperature = sht31.readTemperature();  // Read temperature in Celsius
  float humidity = sht31.readHumidity();        // Read relative humidity in %

  if (!isnan(temperature)) {                    // Check if reading is valid
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" °C");
  } else {
    Serial.println("Error reading temperature.");
  }

  if (!isnan(humidity)) {                       // Check if reading is valid
    Serial.print("Humidity: ");
    Serial.print(humidity);
    Serial.println(" %");
  } else {
    Serial.println("Error reading humidity.");
  }

  delay(2000);                                  // Wait for 2 seconds before the next reading
}

This Arduino sketch uses the Adafruit SHT31 library to communicate with the HTE501 sensor via I2C. The setup() function initializes serial communication, the I2C bus, and the sensor. If the sensor initialization fails, an error message is printed, and the program halts. In the loop() function, temperature and humidity values are read using the library's methods, checked for validity, and then printed to the Serial Monitor. A 2-second delay ensures manageable update intervals.

Connect your ESP32 to your computer via a USB cable, Ensure the correct Board and Port are selected under Tools, Click the "Upload" button in the Arduino IDE to compile and upload the code to your ESP32.

ESP32 HTE501 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the HTE501 Temperature and Humidity Sensor, here's how you can set it up and read data from the sensor. Fill in this code in the main ESP-IDF file:

#include <stdio.h>
#include "driver/i2c.h"
#include "esp_log.h"
#include "sdkconfig.h"

#define I2C_MASTER_SCL_IO 22               // GPIO number for I2C SCL
#define I2C_MASTER_SDA_IO 21               // GPIO number for I2C SDA
#define I2C_MASTER_NUM I2C_NUM_0           // I2C port number for master
#define I2C_MASTER_FREQ_HZ 100000          // I2C master clock frequency
#define I2C_MASTER_TX_BUF_DISABLE 0        // I2C master doesn't need buffer
#define I2C_MASTER_RX_BUF_DISABLE 0        // I2C master doesn't need buffer
#define HTE501_SENSOR_ADDR 0x44            // I2C address for the HTE501 sensor
#define HTE501_CMD_MEASURE 0x2C06          // Command for measurement

static const char *TAG = "HTE501";

void i2c_master_init() {
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = I2C_MASTER_FREQ_HZ,
    };
    i2c_param_config(I2C_MASTER_NUM, &conf);
    i2c_driver_install(I2C_MASTER_NUM, conf.mode, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
}

float read_humidity_temperature(float *temperature, float *humidity) {
    uint8_t data[6];
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (HTE501_SENSOR_ADDR << 1) | I2C_MASTER_WRITE, true);
    i2c_master_write_byte(cmd, HTE501_CMD_MEASURE >> 8, true);
    i2c_master_write_byte(cmd, HTE501_CMD_MEASURE & 0xFF, true);
    i2c_master_stop(cmd);
    i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);

    vTaskDelay(50 / portTICK_RATE_MS); // Wait for measurement

    cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (HTE501_SENSOR_ADDR << 1) | I2C_MASTER_READ, true);
    i2c_master_read(cmd, data, 6, I2C_MASTER_LAST_NACK);
    i2c_master_stop(cmd);
    i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);

    // Convert the data
    uint16_t raw_temp = (data[0] << 8) | data[1];
    uint16_t raw_hum = (data[3] << 8) | data[4];
    *temperature = -45 + 175 * ((float)raw_temp / 65535.0);
    *humidity = 100 * ((float)raw_hum / 65535.0);

    return ESP_OK;
}

void app_main() {
    i2c_master_init();
    float temperature, humidity;

    while (1) {
        if (read_humidity_temperature(&temperature, &humidity) == ESP_OK) {
            ESP_LOGI(TAG, "Temperature: %.2f °C", temperature);
            ESP_LOGI(TAG, "Humidity: %.2f %%", humidity);
        } else {
            ESP_LOGE(TAG, "Could not read from sensor");
        }
        vTaskDelay(2000 / portTICK_RATE_MS); // Delay for 2 seconds
    }
}

This ESP-IDF code sets up an I2C master to communicate with the HTE501 sensor on GPIO pins 21 (SDA) and 22 (SCL). The i2c_master_init() function configures and initializes the I2C interface. The read_humidity_temperature() function sends measurement commands to the sensor, retrieves the raw data, and converts it to temperature and humidity values using the sensor's scaling formulas. In the app_main() function, the temperature and humidity are read in an infinite loop and logged via ESP_LOG. A 2-second delay is added between readings.

Update the I2C pins (I2C_MASTER_SDA_IO and I2C_MASTER_SCL_IO) to match your ESP32 hardware setup, Use idf.py build to compile the project, Use idf.py flash to upload the code to your ESP32.

ESP32 HTE501 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the HTE501 Temperature and Humidity Sensor

sensor:
  - platform: hte501
    temperature:
      name: "Office Temperature"
    humidity:
      name: "Office Humidity"
    address: 0x40
    update_interval: 60s

This ESPHome configuration defines a sensor platform for the HTE501. The platform key specifies the sensor type, and the I2C address is provided under the address key (e.g., 0x40). The temperature and humidity keys define the outputs with user-friendly names like 'Office Temperature' and 'Office Humidity.' The update_interval key ensures sensor readings are updated every 60 seconds.

Upload this code to your ESP32 using the ESPHome dashboard or the esphome run command.

ESP32 HTE501 PlatformIO Code Example

Example in PlatformIO Framework

For PlatformIO, make sure to configure the platformio.ini file with the appropriate environment and libraries, and then proceed with the code.

Configure platformio.ini

First, your platformio.ini should look like below. You might need to include some libraries as shown. Make sure to change the board to your ESP32:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = espidf
monitor_speed = 115200

lib_deps =
    esp-idf-esp32
    Wire

ESP32 HTE501 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the HTE501 Temperature and Humidity Sensor:

#include <stdio.h>
#include "driver/i2c.h"
#include "esp_log.h"

#define I2C_MASTER_SCL_IO 22               // GPIO number for I2C SCL
#define I2C_MASTER_SDA_IO 21               // GPIO number for I2C SDA
#define I2C_MASTER_NUM I2C_NUM_0           // I2C port number for master
#define I2C_MASTER_FREQ_HZ 100000          // I2C master clock frequency
#define I2C_MASTER_TX_BUF_DISABLE 0        // I2C master doesn't need buffer
#define I2C_MASTER_RX_BUF_DISABLE 0        // I2C master doesn't need buffer
#define HTE501_SENSOR_ADDR 0x44            // I2C address for the HTE501 sensor
#define HTE501_CMD_MEASURE 0x2C06          // Command for measurement

static const char *TAG = "HTE501";

void i2c_master_init() {
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = I2C_MASTER_FREQ_HZ,
    };
    i2c_param_config(I2C_MASTER_NUM, &conf);
    i2c_driver_install(I2C_MASTER_NUM, conf.mode, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
}

float read_humidity_temperature(float *temperature, float *humidity) {
    uint8_t data[6];
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (HTE501_SENSOR_ADDR << 1) | I2C_MASTER_WRITE, true);
    i2c_master_write_byte(cmd, HTE501_CMD_MEASURE >> 8, true);
    i2c_master_write_byte(cmd, HTE501_CMD_MEASURE & 0xFF, true);
    i2c_master_stop(cmd);
    i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);

    vTaskDelay(50 / portTICK_RATE_MS); // Wait for measurement

    cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (HTE501_SENSOR_ADDR << 1) | I2C_MASTER_READ, true);
    i2c_master_read(cmd, data, 6, I2C_MASTER_LAST_NACK);
    i2c_master_stop(cmd);
    i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);

    // Convert the data
    uint16_t raw_temp = (data[0] << 8) | data[1];
    uint16_t raw_hum = (data[3] << 8) | data[4];
    *temperature = -45 + 175 * ((float)raw_temp / 65535.0);
    *humidity = 100 * ((float)raw_hum / 65535.0);

    return ESP_OK;
}

void app_main() {
    i2c_master_init();
    float temperature, humidity;

    while (1) {
        if (read_humidity_temperature(&temperature, &humidity) == ESP_OK) {
            ESP_LOGI(TAG, "Temperature: %.2f °C", temperature);
            ESP_LOGI(TAG, "Humidity: %.2f %%", humidity);
        } else {
            ESP_LOGE(TAG, "Could not read from sensor");
        }
        vTaskDelay(2000 / portTICK_RATE_MS); // Delay for 2 seconds
    }
}

This PlatformIO ESP-IDF code initializes I2C communication to interface with the HTE501 sensor. The i2c_master_init() function configures the I2C master interface with GPIO pins 21 (SDA) and 22 (SCL). The read_humidity_temperature() function sends measurement commands to the HTE501, retrieves the raw sensor data, and calculates temperature and humidity using the sensor's conversion formulas. The app_main() function continuously reads and logs temperature and humidity values every 2 seconds.

Upload the code to your ESP32 using the PlatformIO "Upload" button in your IDE or the pio run --target upload command.