ESP32 DHT20 Temperature and Humidity Sensor

🛠️ DHT20 Temperature and Humidity Sensor Troubleshooting

This guide outlines a systematic approach to troubleshoot and resolve common problems with the . Start by confirming that the hardware connections are correct, as wiring mistakes are the most frequent cause of issues. If you are sure the connections are correct, follow the below steps to debug common issues.

❌ Initialization Failure

⚠️ Incorrect Readings

🚫 Communication Errors

💻 Code Examples

Below you can find code examples of DHT20 Temperature and Humidity Sensor with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO

If you encounter issues while using the DHT20 Temperature and Humidity Sensor, check the Common Issues Troubleshooting Guide.

ESP32 DHT20 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the DHT20 Temperature and Humidity Sensor:

#include <Wire.h>
#include "DFRobot_DHT20.h"

DFRobot_DHT20 dht20;

void setup() {
  Serial.begin(115200);
  while (dht20.begin()) {
    Serial.println("Failed to initialize DHT20 sensor!");
    delay(1000);
  }
}

void loop() {
  float temperature = dht20.getTemperature();
  float humidity = dht20.getHumidity();
  Serial.print("Temperature: ");
  Serial.print(temperature, 1);
  Serial.println(" °C");
  Serial.print("Humidity: ");
  Serial.print(humidity * 100, 1);
  Serial.println(" %");
  delay(2000);
}

This Arduino code initializes the DHT20 sensor using the DFRobot DHT20 library. In the setup() function, it attempts to initialize the sensor and prints an error message if initialization fails. In the loop() function, it reads the temperature and humidity values from the sensor and prints them to the Serial Monitor every two seconds.

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 DHT20 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the DHT20 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 "dht20.h"
#include "esp_log.h"

#define I2C_MASTER_SCL_IO 22
#define I2C_MASTER_SDA_IO 21
#define I2C_MASTER_FREQ_HZ 100000
#define DHT20_ADDR 0x38

static const char *TAG = "DHT20";

void app_main() {
    ESP_LOGI(TAG, "Initializing DHT20...");
    dht20_dev_t dev;
    dht20_init(&dev, I2C_MASTER_SCL_IO, I2C_MASTER_SDA_IO, I2C_MASTER_FREQ_HZ, DHT20_ADDR);

    while (1) {
        dht20_data_t data;
        if (dht20_read(&dev, &data) == ESP_OK) {
            ESP_LOGI(TAG, "Temperature: %.2f°C", data.temperature);
            ESP_LOGI(TAG, "Humidity: %.2f%%", data.humidity);
        } else {
            ESP_LOGE(TAG, "Failed to read data from DHT20 sensor");
        }
        vTaskDelay(2000 / portTICK_PERIOD_MS);
    }
}

This ESP-IDF code configures the ESP32 to communicate with the DHT20 sensor via I²C. The dht20_init function initializes the sensor, while the dht20_read function fetches temperature and humidity data. If successful, the data is logged to the console every two seconds; otherwise, an error message is displayed.

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 DHT20 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the DHT20 Temperature and Humidity Sensor

sensor:
  - platform: dht
    model: DHT20
    pin: I2C
    temperature:
      name: "DHT20 Temperature"
    humidity:
      name: "DHT20 Humidity"
    update_interval: 2s

This ESPHome configuration sets up the DHT20 sensor to provide temperature and humidity data over the I²C interface. The sensor readings update every two seconds.

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

ESP32 DHT20 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 DHT20 Library
    wire
monitor_speed = 115200

ESP32 DHT20 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the DHT20 Temperature and Humidity Sensor:

#include <Wire.h>
#include "DFRobot_DHT20.h"

DFRobot_DHT20 dht20;

void setup() {
  Serial.begin(115200);
  while (dht20.begin()) {
    Serial.println("Failed to initialize DHT20 sensor!");
    delay(1000);
  }
}

void loop() {
  Serial.print("Temperature: ");
  Serial.print(dht20.getTemperature(), 1);
  Serial.println(" °C");
  Serial.print("Humidity: ");
  Serial.print(dht20.getHumidity(), 1);
  Serial.println(" %");
  delay(2000);
}

This PlatformIO code initializes the DHT20 sensor using the DFRobot DHT20 library. The program continuously reads temperature and humidity values and prints them to the Serial Monitor every two seconds.

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