ESP32 SHT20 Temperature and Humidity Sensor

Code Examples

Below you can find code examples of SHT20 Temperature and Humidity Sensor with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO
• MicroPython

ESP32 SHT20 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the SHT20 Temperature and Humidity Sensor:

#include <Wire.h>
#include "DFRobot_SHT20.h"

DFRobot_SHT20 sht20;

void setup() {
  Serial.begin(115200);
  Wire.begin();
  sht20.initSHT20();
  delay(100);
  sht20.checkSHT20();
}

void loop() {
  float humidity = sht20.readHumidity();
  float temperature = sht20.readTemperature();
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");
  delay(2000);
}

This Arduino sketch demonstrates how to interface with the SHT20 sensor using the DFRobot_SHT20 library. It initializes the sensor and reads temperature and humidity data every 2 seconds, printing the results to the Serial Monitor. Ensure that the DFRobot_SHT20 library is installed in your Arduino IDE.

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 SHT20 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the SHT20 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 "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/i2c.h"

#define I2C_MASTER_SCL_IO    22    /*!< GPIO number used for I2C master clock */
#define I2C_MASTER_SDA_IO    21    /*!< GPIO number used for I2C master data */
#define I2C_MASTER_NUM       I2C_NUM_0 /*!< I2C master I2C port number */
#define I2C_MASTER_FREQ_HZ   100000     /*!< I2C master clock frequency */
#define SHT20_SENSOR_ADDR    0x40       /*!< SHT20 I2C address */

static esp_err_t i2c_master_init(void) {
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = I2C_MASTER_FREQ_HZ,
    };
    esp_err_t err = i2c_param_config(I2C_MASTER_NUM, &conf);
    if (err != ESP_OK) {
        return err;
    }
    return i2c_driver_install(I2C_MASTER_NUM, conf.mode, 0, 0, 0);
}

void read_sht20_sensor() {
    uint8_t data[3];
    uint8_t cmd = 0xF5; // Command for humidity measurement
    i2c_master_write_to_device(I2C_MASTER_NUM, SHT20_SENSOR_ADDR, &cmd, 1, pdMS_TO_TICKS(1000));
    vTaskDelay(pdMS_TO_TICKS(50));
    i2c_master_read_from_device(I2C_MASTER_NUM, SHT20_SENSOR_ADDR, data, 3, pdMS_TO_TICKS(1000));

    uint16_t raw_humidity = (data[0] << 8) | (data[1] & 0xFC);
    float humidity = -6.0 + 125.0 * (raw_humidity / 65536.0);

    cmd = 0xF3; // Command for temperature measurement
    i2c_master_write_to_device(I2C_MASTER_NUM, SHT20_SENSOR_ADDR, &cmd, 1, pdMS_TO_TICKS(1000));
    vTaskDelay(pdMS_TO_TICKS(50));
    i2c_master_read_from_device(I2C_MASTER_NUM, SHT20_SENSOR_ADDR, data, 3, pdMS_TO_TICKS(1000));

    uint16_t raw_temperature = (data[0] << 8) | (data[1] & 0xFC);
    float temperature = -46.85 + 175.72 * (raw_temperature / 65536.0);

    printf("Temperature: %.2f °C, Humidity: %.2f %%\n", temperature, humidity);
}

void app_main() {
    ESP_ERROR_CHECK(i2c_master_init());

    while (1) {
        read_sht20_sensor();
        vTaskDelay(pdMS_TO_TICKS(2000));
    }
}

This ESP-IDF code interfaces with the SHT20 sensor using the I2C protocol. The `read_sht20_sensor()` function reads raw temperature and humidity data by sending the appropriate commands to the sensor and processing the response. The results are converted into human-readable temperature (°C) and humidity (%) values and printed to the console every 2 seconds.

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 SHT20 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the SHT20 Temperature and Humidity Sensor

sensor:
  - platform: sht3x
    address: 0x40
    temperature:
      name: "Room Temperature"
    humidity:
      name: "Room Humidity"
    update_interval: 60s

This ESPHome configuration defines the SHT20 sensor using the `sht3x` platform. The I2C address of the sensor is set to 0x40, and two sensor entities are created: one for temperature and one for humidity. The `update_interval` is set to 60 seconds, meaning the sensor readings will be updated every minute.

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

ESP32 SHT20 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 = arduino
lib_deps = 
    DFRobot/DFRobot_SHT20 @ ^1.0.0
monitor_speed = 115200

ESP32 SHT20 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the SHT20 Temperature and Humidity Sensor:

#include <Wire.h>
#include "DFRobot_SHT20.h"

DFRobot_SHT20 sht20;

void setup() {
    Serial.begin(115200);
    Wire.begin();
    sht20.initSHT20();
    delay(100);
    sht20.checkSHT20();
}

void loop() {
    float humidity = sht20.readHumidity();
    float temperature = sht20.readTemperature();

    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" °C");

    Serial.print("Humidity: ");
    Serial.print(humidity);
    Serial.println(" %");

    delay(2000);
}

This PlatformIO code demonstrates how to interface with the SHT20 sensor using the DFRobot_SHT20 library. The code initializes the sensor, reads temperature and humidity data every 2 seconds, and prints the results to the Serial Monitor.

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

ESP32 SHT20 MicroPython Code Example

Example in Micro Python Framework

Fill in this script in your MicroPython main.py file (main.py) to integrate the SHT20 Temperature and Humidity Sensor with your ESP32.

from machine import Pin, I2C
from time import sleep

# Initialize I2C
i2c = I2C(0, scl=Pin(22), sda=Pin(21))
SHT20_ADDR = 0x40

# Function to read data from the SHT20
def read_sht20(cmd):
    i2c.writeto(SHT20_ADDR, bytearray([cmd]))
    sleep(0.05)
    data = i2c.readfrom(SHT20_ADDR, 3)
    raw = (data[0] << 8) | (data[1] & 0xFC)
    return raw

while True:
    # Read humidity
    raw_humidity = read_sht20(0xF5)
    humidity = -6.0 + 125.0 * (raw_humidity / 65536.0)

    # Read temperature
    raw_temperature = read_sht20(0xF3)
    temperature = -46.85 + 175.72 * (raw_temperature / 65536.0)

    print(f"Temperature: {temperature:.2f} °C, Humidity: {humidity:.2f} %")
    sleep(2)

This MicroPython code interfaces with the SHT20 sensor using I2C. It sends commands to the sensor to read raw temperature and humidity data, processes the raw data into human-readable values, and prints the results every 2 seconds.

Upload this code to your ESP32 using a MicroPython-compatible IDE, such as Thonny, uPyCraft, or tools like ampy.