How to Build Your First Arduino Project with UNO and OLED
Build your first Arduino project from a UNO R3 board, a 0.96 inch OLED display, and a DHT22 sensor. The board costs $9.27 with an ATmega328P chip at 16MHz. The display shows 128 by 64 pixels over I2C. The sensor reads 0 to 100% relative humidity and -40 to 80C for $5.96.
Quick facts
| Fact | Value |
|---|---|
| UNO R3 board | $9.27, ATmega328P, 16MHz, 14 digital pins |
| OLED display | $5.47, 0.96 inch, 128 by 64 pixels, I2C |
| DHT22 sensor | $5.96, 0 to 100% RH, -40 to 80C |
| BMP280 sensor | $6.77, 300 to 1100 hPa, 5-pack |
| Switch kit | $11.31, 180 switches, 10 values |
| TM1637 display | $6.21, 0.56 inch, 4 digits |
What parts do you need for the first project?
You need a UNO R3 board at $9.27, an OLED display at $5.47, and a DHT22 sensor at $5.96.
The board carries an ATmega328P chip with a CH340G USB-serial chip. It runs at 16MHz and works with the Arduino IDE.
The display measures 0.96 inch with 128 by 64 pixels on I2C. The sensor reads 0 to 100% relative humidity and -40 to 80C.
How do you wire the OLED display?
Wire the display to the UNO I2C pins with 4 short wires.
Connect SDA to A4 and SCL to A5 on the UNO R3 board. Power the display from the 5V pin and ground from GND.
The display takes 3.3V to 5V, so the UNO 5V pin works. Keep the wires short to avoid noise on the I2C lines.
How do you wire the DHT22 sensor?
Wire the DHT22 data pin to a digital pin on the UNO board.
It runs on 3.3V to 5.5V with a single-bus output. That range suits the UNO board with no extra parts.
Read it once per 2 sec, since the sensor needs time between reads. A fast read returns stale numbers.
What does the sketch do?
The sketch reads the sensor, then draws the values on the display.
It reads temperature and humidity from the DHT22 sensor. It draws both numbers on the 128 by 64 pixel display.
Update the display once per loop so the numbers stay readable. Load a blink sketch first to confirm the board and USB link.
How do you add a button to the project?
Wire one switch between a digital pin and ground.
The tactile switch kit holds 180 momentary switches in 10 values. It covers 6x6mm sizes from 4.3mm to 13mm, plus 7x7x14mm.
The kit costs $11.31 with an organizer box. Use the built-in pull-up resistor in the sketch for the button.
What can you build next?
Swap the DHT22 for a BMP280 to add air pressure readings.
The BMP280 reads 300 to 1100 hPa with plus or minus 1 hPa accuracy. Its 5-pack costs $6.77 for the 3.3V version.
Swap the UNO for an ESP32 DevKit V1 at $11.99 to add WiFi. Its Type-C board costs $15.99 with 30 pins.
How the options compare
| Part | Key spec | Price |
|---|---|---|
| UNO R3 board | ATmega328P, 16MHz, 14 digital pins | $9.27 |
| OLED display | 0.96 inch, 128 by 64 pixels, I2C | $5.47 |
| DHT22 sensor | 0 to 100% RH, -40 to 80C | $5.96 |
| BMP280 sensor | 300 to 1100 hPa, I2C or SPI | $6.77, 5-pack |
| Tactile switch kit | 180 switches, 10 values | $11.31 |
| TM1637 display | 0.56 inch, 4 digits, 2 pins | $6.21 |
How do you build your first Arduino project?
- Connect the UNO board to your computer over USB.
- Pick the Arduino Uno board in the Arduino IDE.
- Load a blink sketch to confirm the board and USB link.
- Wire the OLED display to the I2C pins, GND, VCC, SCL, and SDA.
- Wire the DHT22 data pin to a digital pin.
- Load the sketch and check that the display shows temperature and humidity.
Parts that fit this guide
In-stock parts ship from the New York, USA warehouse in 1-2 business days. Prices below are the live store prices we verified on November 10, 2026.
UNO R3 Compatible Development Board, ATmega328P CH340G – USB / Type-C ($9.27)
UNO R3 compatible board at $9.27 to $10.64 by version. It carries an ATmega328P chip, runs at 16MHz, and gives 14 digital pins and 6 analog inputs.
0.96 Inch OLED Display Module, SSD1306, I2C, 128×64, for Arduino / ESP32 / ESP8266 ($5.47)
OLED display at $5.47 for blue. It measures 0.96 inch with 128 by 64 pixels on I2C, and takes 3.3V to 5V.
DHT22 / AM2302 Digital Temperature & Humidity Sensor Module ($5.96)
DHT22 sensor at $5.96. It reads 0 to 100% relative humidity and -40 to 80C on 3.3V to 5.5V.
Tactile Pushbutton Switch Kit, 6x6mm, 10 Values, 180-Piece with Organizer Box ($11.31)
Tactile switch kit at $11.31. It holds 180 momentary switches in 10 values with an organizer box.
Shop the full range: Arduino-Compatible Boards at Quality RC Parts. See also: Related guide.
Frequently asked questions
What board do I need for my first Arduino project?
A UNO R3 compatible board at $9.27. It carries an ATmega328P chip at 16MHz with 14 digital pins.
What display works with the UNO board?
The 0.96 inch OLED display at $5.47. It runs on I2C with 4 pins and takes 3.3V to 5V.
What sensor reads temperature and humidity?
The DHT22 sensor at $5.96. It reads 0 to 100% relative humidity and -40 to 80C.
Can I add a button to the project?
Yes. The tactile switch kit costs $11.31 and holds 180 momentary switches in 10 values.
Sources
- Arduino Uno Rev3 documentation
- Arduino getting started guide
- Adafruit DHT temperature and humidity sensor guide
Last updated: November 10, 2026.