How use HTU21DF Humidity and Temperature Sensor with Arduino (Basic Code)

Project Video
Project Details

This is basic code to measure temperature and himidity usiung HTUD21DF sensor. Full hardware, two types of code and
demonstation is shonw
in the video. The code is available below this video. To see custom code shown in video click

Topics Covered in this tutorial

  • 00:00 Introduction
  • 01:45 Hardware explaine
  • 03:45 Wiring explained
    04:33 Code Explained (basic code)
  • 09:04 Demonstration of basic code
  • 10:04 Custom Code explained
  • 13:04 Demonstration of custom code
Project Images

Project Code

  This is an example for the HTU21D-F Humidity & Temp Sensor

  Designed specifically to work with the HTU21D-F sensor from Adafruit

  These displays use I2C to communicate, 2 pins are required to

#include "Adafruit_HTU21DF.h"

// Connect Vin to 3-5VDC
// Connect GND to ground
// Connect SCL to I2C clock pin (A5 on UNO)
// Connect SDA to I2C data pin (A4 on UNO)

Adafruit_HTU21DF htu = Adafruit_HTU21DF();

void setup() {
  Serial.println("HTU21D-F test");

  if (!htu.begin()) {
    Serial.println("Couldn't find sensor!");
    while (1);

void loop() {
    float temp = htu.readTemperature();
    float rel_hum = htu.readHumidity();
    Serial.print("Temp: "); Serial.print(temp); Serial.print(" C");
    Serial.print("Humidity: "); Serial.print(rel_hum); Serial.println(" \%");

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