Arduino 3D Printed Digital Thermometer With DHT-22 Sensor

In this guide I will show you how to make your own Arduino digital thermometer by using the DHT-22 sensor and Arduino Pro Mini board. It can be powered up from any USB power source and it can report the max and min values for temperature and humidity as it works.

In this guide you will also find the .stl files of the 3d printed case/box.

The DHT-22 (also named as AM2302) is a digital-output relative humidity and temperature sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin.

The DHT22 is a basic, low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed).

Technical details of DHT-22:

• Power: 3-5V
• Max Current: 2.5mA
• Humidity: 0-100%, 2-5% accuracy
• Temperature: -40 to 80°C, ±0.5°C accuracy

Video:

Project updates can be found here: http://www.ardumotive.com/3d-printed-thermometeren.html

Let's get started!

Step 1: What You Will Need - Hardware

For this project you will need:

• Arduino Pro Mini (5V)
• Nokia 5110 display (pcb version)
• DHT-22
• On/off button (with Mounting hole diameter Ø12.5mm)
• USB cable for powerTTL to USB Arduino board to program it

You will also need 4x 3mm screws and glue.

Step 2: 3D Printer Files

You can download the .stl 3D files from here:

https://www.thingiverse.com/thing:2391472

Step 3: The Circuit

The circuit is very simple, follow the steps below:

DHT-22:

• Vcc to Arduino Pro mini Vcc (or 5V)
• GNG to GND
• Analog signal to Arduino pin 10

LCD Screen

• Vcc to Arduino Pro mini Vcc (or 5V)
• GND to Arduino Pro mini GND
• CS to Arduino pin 4
• RST to Arduino pin 3
• DC to Arduino pin 5
• DN to Arduino pin 6
• SCLK to Arduino pin 7
• BL to Vcc - 5V

USB cable:

Cut it and find the + and - cables. Use a voltometer or multimeter tool. Finally make the connection:

• + cable to Button switch and then to Arduino Pro Mini Vcc pin
• - cable to Arduino Pro mini GND pin

Step 4: The Code

Download the code from here and open it with Arduino IDE.

Inside you will also find all necessary libraries.

Step 5: ​Well Done!

Well...that's it!

I hope you liked this, let me know in the comments!

Find more Arduino DIY Projects at www.Ardumotive.com