ESP32 MicroPython DHT11 Temperature Humidity Sensor
This tutorial instructs you how to use the DHT11 temperature and humidity sensor with the ESP32 and MicroPython. In detail, we will learn:
- How to connect the DHT11 sensor and module to a ESP32.
- How to write MicroPython code for the ESP32 to read temperature and humidity data from the DHT11 sensor and module.
Hardware Preparation
| 1 | × | ESP-WROOM-32 Dev Module | |
| 1 | × | USB Cable Type-C | |
| 1 | × | DHT11 Module | |
| 1 | × | 10 kΩ resistor | |
| 1 | × | Breadboard | |
| 1 | × | Jumper Wires | |
| 1 | × | (Recommended) Screw Terminal Expansion Board for ESP32 |
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables.
Additionally, some of these links are for products from our own brand, DIYables.
Overview of DHT11 Temperature and Humidity Sensor
| DHT11 | |
|---|---|
| Operating Voltage | 3 to 5V |
| Temperature Range | 0°C to 50°C |
| Temperature Accuracy | ± 2°C |
| Humidity Range | 20% to 80% |
| Humidity Accuracy | 5% |
| Reading Rate | 1Hz (once every second) |
Pinout
There are two versions of the DHT11: a sensor and a module.
The DHT11 sensor comes with four pins.
- GND pin: connect to GND (0 volts)
- VCC pin: connect to VCC (5 volts or 3.3 volts)
- DATA pin: used for sending information to and from the sensor and ESP32
- NC pin: not used, you can ignore it
The DHT11 module comes with three pins.
- GND pin: connect to GND (0 volts).
- VCC pin: connect to VCC (5 volts or 3.3 volts).
- DATA pin: used for communication between the sensor and ESP32.
Some manufacturers provide the DHT11 sensor as a module with three pins named: GND, VCC, and DATA (or sometimes as -, +, and OUT).
Wiring Diagram
ESP32 - DHT11 Sensor Wiring Diagram
To connect the DHT11 sensor to the ESP32, use a resistor ranging from 5K to 10K Ohms. This resistor keeps the data line high, ensuring good communication between the sensor and the ESP32. We need to use a breadboard in this case.
This image is created using Fritzing. Click to enlarge image
ESP32 - DHT11 Module Wiring Diagram
Most DHT11 sensor modules have a resistor already included, so you don't need to add another one. This simplifies the process of wiring or soldering.
- How to connect ESP32 and DHT11 temperature humidity module using breadboard
This image is created using Fritzing. Click to enlarge image
- How to connect ESP32 and DHT11 temperature humidity sensor using screw terminal block breakout board
ESP32 MicroPython Code - DHT11
"""
This ESP32 MicroPython code was developed by newbiely.com
This ESP32 MicroPython code is made available for public use without any restriction
For comprehensive instructions and wiring diagrams, please visit:
https://newbiely.com/tutorials/esp32-micropython/esp32-micropython-dht11-temperature-humidity-sensor
"""
import machine
import time
import dht
DHT11_PIN = 21 # The ESP32 pin GPIO21 connected to the DHT11 sensor
# Initialize the DHT11 sensor
DHT11 = dht.DHT11(machine.Pin(DHT11_PIN))
# Read data from the sensor every 2 seconds
while True:
try:
DHT11.measure()
temp = DHT11.temperature() # Gets the temperature in Celsius
humidity = DHT11.humidity() # Gets the relative humidity in %
print("Temperature: {:.2f}°C, Humidity: {:.2f}%".format(temp, humidity))
except OSError as e:
print("Failed to read from DHT11 sensor:", e)
time.sleep(2)
Detailed Instructions
Here’s instructions on how to set up and run your MicroPython code on the ESP32 using Thonny IDE:
- Make sure Thonny IDE is installed on your computer.
- Confirm that MicroPython firmware is loaded on your ESP32 board.
- If this is your first time using an ESP32 with MicroPython, check out the ESP32 MicroPython Getting Started guide for step-by-step instructions.
- Connect the DHT11 sensor/module to ESP32 board according to the provided diagram.
- Connect the ESP32 board to your computer with a USB cable.
- Open Thonny IDE on your computer.
- In Thonny IDE, go to Tools Options.
- Under the Interpreter tab, choose MicroPython (ESP32) from the dropdown menu.
- Make sure the correct port is selected. Thonny IDE usually detects it automatically, but you might need to select it manually (like COM12 on Windows or /dev/ttyACM0 on Linux).
- Copy the provided MicroPython code and paste it into Thonny\'s editor.
- Save the code to your ESP32 by:
- Clicking the Save button or pressing Ctrl+S.
- In the save dialog, choose MicroPython device.
- Name the file main.py.
- Click the green Run button (or press F5) to execute the script.
- Adjust the temperature near the DHT11 sensor to be warmer or cooler.
- Check out the message in the Shell at the bottom of Thonny.
Shell x
>>> %Run -c $EDITOR_CONTENT
MPY: soft reboot
Temperature: 24.00°C, Humidity: 55.00%
Temperature: 24.00°C, Humidity: 63.00%
Temperature: 24.00°C, Humidity: 64.00%
Temperature: 24.00°C, Humidity: 73.00%
Temperature: 25.00°C, Humidity: 74.00%
Temperature: 25.00°C, Humidity: 75.00%
Temperature: 25.00°C, Humidity: 76.00%
Temperature: 25.00°C, Humidity: 78.00%
Temperature: 25.00°C, Humidity: 79.00%
Temperature: 25.00°C, Humidity: 79.00%
Temperature: 25.00°C, Humidity: 79.00%
Temperature: 26.00°C, Humidity: 78.00%
MicroPython (ESP32) • CP2102 USB To UART Bridge Controller @ COM12 ≡