ESP32 SHT40 Temperature and Humidity Sensor

🛠️ SHT40 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.

❌ Sensor Initialization Failure

⚠️ Incorrect Temperature or Humidity Readings

🔄 Intermittent I²C Communication

💻 Code Examples

Below you can find code examples of SHT40 Temperature and Humidity Sensor with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO

If you encounter issues while using the SHT40 Temperature and Humidity Sensor, check the Common Issues Troubleshooting Guide.

ESP32 SHT40 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the SHT40 Temperature and Humidity Sensor:

#include <Wire.h>
#include "Adafruit_SHT4x.h"

Adafruit_SHT4x sht4 = Adafruit_SHT4x();

void setup() {
  Serial.begin(115200);
  if (!sht4.begin()) {
    Serial.println("Couldn't find SHT4x");
    while (1) delay(10);
  }
  Serial.println("Found SHT4x sensor");
}

void loop() {
  sensors_event_t humidity, temp;
  sht4.getEvent(&humidity, &temp);
  Serial.print("Temperature: ");
  Serial.print(temp.temperature);
  Serial.println(" °C");
  Serial.print("Humidity: ");
  Serial.print(humidity.relative_humidity);
  Serial.println(" %");
  delay(2000);
}

This Arduino code initializes the SHT40 sensor using the Adafruit SHT4x library. In the setup() function, it sets up serial communication and attempts to initialize the sensor. If the sensor is not found, it prints an error message and halts execution. In the loop() function, it reads temperature and humidity data from the sensor and prints the values 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 SHT40 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the SHT40 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 "sht4x.h"
#include "esp_log.h"

#define I2C_MASTER_SCL_IO 22
#define I2C_MASTER_SDA_IO 21
#define I2C_MASTER_FREQ_HZ 100000
#define SHT40_ADDR 0x44

static const char *TAG = "SHT40";

void app_main() {
    ESP_LOGI(TAG, "Initializing SHT40...");
    sht4x_dev_t dev;
    sht4x_init(&dev, I2C_MASTER_SCL_IO, I2C_MASTER_SDA_IO, I2C_MASTER_FREQ_HZ, SHT40_ADDR);

    while (1) {
        float temperature, humidity;
        if (sht4x_read_temperature(&dev, &temperature) == ESP_OK &&
            sht4x_read_humidity(&dev, &humidity) == ESP_OK) {
            ESP_LOGI(TAG, "Temperature: %.2f°C", temperature);
            ESP_LOGI(TAG, "Humidity: %.2f%%", humidity);
        } else {
            ESP_LOGE(TAG, "Failed to read data from SHT40 sensor");
        }
        vTaskDelay(2000 / portTICK_PERIOD_MS);
    }
}

This ESP-IDF code configures the ESP32 to communicate with the SHT40 sensor over I²C. The sht4x_init function initializes the sensor, while sht4x_read_temperature and sht4x_read_humidity fetch temperature and humidity data. The values are logged to the console every two seconds, and errors are reported if data retrieval fails.

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 SHT40 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the SHT40 Temperature and Humidity Sensor

sensor:
  - platform: sht4x
    temperature:
      name: "SHT40 Temperature"
    humidity:
      name: "SHT40 Humidity"
    address: 0x44
    update_interval: 2s

This ESPHome configuration sets up the SHT40 sensor to measure temperature and humidity over I²C. The sensor readings update every two seconds, and the default I²C address is 0x44.

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

ESP32 SHT40 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 = 
    adafruit/Adafruit SHT4x Library
    wire
monitor_speed = 115200

ESP32 SHT40 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the SHT40 Temperature and Humidity Sensor:

#include <Wire.h>
#include "Adafruit_SHT4x.h"

Adafruit_SHT4x sht4 = Adafruit_SHT4x();

void setup() {
  Serial.begin(115200);
  if (!sht4.begin()) {
    Serial.println("Couldn't find SHT4x");
    while (1) delay(10);
  }
  Serial.println("Found SHT4x sensor");
}

void loop() {
  sensors_event_t humidity, temp;
  sht4.getEvent(&humidity, &temp);
  Serial.print("Temperature: ");
  Serial.print(temp.temperature);
  Serial.println(" °C");
  Serial.print("Humidity: ");
  Serial.print(humidity.relative_humidity);
  Serial.println(" %");
  delay(2000);
}

This PlatformIO code initializes the SHT40 sensor using the Adafruit SHT4x library. The sensor communicates over I²C, and the program continuously reads and prints temperature and humidity values 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.