How to display the temperature and humidity from the DHT sensor on an LCD screen?

#raspberrypi #dht11 #dht22 #python

Let’s display the temperature and humidity from the DHT sensor on an LCD screen using Python on a Raspberry Pi.

Project: Display Sensor Data on 16x2 LCD with I2C
What You Need:

Raspberry Pi
DHT11 or DHT22 sensor
I2C 16x2 LCD module (with I2C backpack)
10kΩ pull-up resistor (if using raw DHT)
Breadboard and jumper wires

Wiring the I2C LCD to Raspberry Pi:

Enable I2C on Raspberry Pi:

bash sudo raspi-config

Go to Interface Options > I2C > Enable

Then reboot:

bash sudo reboot

Step 1: Install Required Libraries

bash sudo apt update sudo apt install python3-pip i2c-tools pip3 install adafruit-circuitpython-charlcd pip3 install Adafruit_DHT

Step 2: Find Your I2C Address
Run:

bash i2cdetect -y 1

Look for an address like 0x27 or 0x3F (that’s your LCD address).

Step 3: Python Script
Create a file:

bash nano lcd_dht.py

Paste this code (make sure to adjust your I2C address if needed):

python import time import board import busio import adafruit_character_lcd.character_lcd_i2c as character_lcd import Adafruit_DHT # Set up DHT sensor sensor = Adafruit_DHT.DHT11 dht_pin = 4 # Set up I2C and LCD i2c = busio.I2C(board.SCL, board.SDA) lcd_columns = 16 lcd_rows = 2 lcd = character_lcd.Character_LCD_I2C(i2c, lcd_columns, lcd_rows) # Clear screen lcd.clear() try: while True: humidity, temperature = Adafruit_DHT.read_retry(sensor, dht_pin) if humidity is not None and temperature is not None: lcd.clear() lcd.message = f"Temp:{temperature:.1f}C\nHum:{humidity:.1f}%" else: lcd.clear() lcd.message = "Sensor Error" time.sleep(2) except KeyboardInterrupt: lcd.clear() lcd.message = "Goodbye!" time.sleep(2) lcd.clear()

Save and exit (Ctrl+X, then Y, then Enter).

Run It: