How to Choose Arduino Boards for Robotics Projects
Choose an Arduino board for a robot by pins, size, and sensors. The UNO gives 14 digital pins for bench robots, while the Nano fits small chassis. The UNO costs from $9.27, and the Nano costs $10.96. A line sensor adds track following for $7.02 per 4-pack.
Quick facts
| Fact | Value |
|---|---|
| UNO R3 | From $9.27, ATmega328P, 16MHz, 14 digital pins |
| Nano 3.0 | $10.96, ATmega328PB, CH340C, Type-C |
| TCRT5000 sensor | $7.02, 4-pack, 1 to 25mm range |
| PIR sensor | $7.62, 2-pack, up to 7m range |
| MQ-2 sensor | $5.81, 300 to 10,000ppm, 5V heater |
Which Arduino board fits a first robot?
The UNO R3 gives 14 digital I/O pins and 6 analog inputs. It carries an ATmega328P chip at 16MHz and costs from $9.27.
The Nano 3.0 gives the same Arduino workflow in a small case. It carries an ATmega328PB chip with Type-C USB for $10.96.
Pick the UNO for bench robots where pins must stay visible. Pick the Nano for small chassis where the board must fit.
What sensors guide a robot?
The TCRT5000 line sensor reads 1 to 25mm with a digital output. It costs $7.02 for a 4-pack and takes 3.3V to 5V.
The PIR sensor sees motion up to 7m away inside a cone under 120 degrees. A 2-pack costs $7.62 with a 0.3 to 18 sec delay.
The MQ-2 gas sensor reads 300 to 10,000ppm for $5.81. It detects smoke and gas with a 5V heater.
How do you sense motion and gas?
The PIR sensor runs on 5V to 20V and holds its output for 0.3 to 18 sec. Set a short delay for alerts and a long delay for logs.
The MQ-2 sensor detects LPG, methane, propane, butane, alcohol, hydrogen, and smoke. It reads 300 to 10,000ppm on a 5V heater.
Wire each sensor output to a free GPIO pin. Test each sensor on the bench before the robot moves.
How do you drive servos from a robot board?
The Arduino Servo library drives a servo from a GPIO pin. It sends a 50 Hz signal with a 1 to 2 ms pulse to set the angle.
Power servos from a separate 5V to 6V supply, not from the board. A servo draws far more current than a board pin can give.
Join the grounds of the servo supply and the board. A missing common ground makes servos jitter and ignore commands.
Which board fits a tiny robot?
The Nano 3.0 costs $10.96 and fits a breadboard or a small chassis. Its ATmega328PB chip runs the same Arduino code as the UNO.
The UNO R3 costs from $9.27 and suits bench robots with visible pins. Both boards work with the Arduino IDE.
Pick the Nano when the chassis leaves no room for a full UNO. Pick the UNO when you learn Arduino for the first time.
How the options compare
| Part | Key spec | Price |
|---|---|---|
| UNO R3, Type-C | ATmega328P, 16MHz, 14 digital pins | $9.27 |
| Nano 3.0 | ATmega328PB, CH340C, Type-C | $10.96 |
| TCRT5000, 4-pack | 1 to 25mm, digital output | $7.02 |
| PIR sensor, 2-pack | Up to 7m, 0.3 to 18 sec delay | $7.62 |
| MQ-2 sensor | 300 to 10,000ppm, 5V heater | $5.81 |
How do you build a first Arduino robot?
- Pick the UNO for the bench or the Nano for a small chassis.
- Wire the TCRT5000 line sensors to digital pins.
- Wire each servo signal pin to a separate GPIO pin.
- Connect the servos to a 5V to 6V supply with a common ground.
- Load a test sketch and move each servo through its range.
- Test the line sensors on a track before the first run.
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.
TCRT5000 Infrared Reflective Line Tracking Sensor Module, 4-Pack ($7.02)
TCRT5000 sensor at $7.02 for a 4-pack. It reads 1 to 25mm with a digital output on 3.3V to 5V.
HC-SR501 PIR Motion Sensor Module, 2-Pack ($7.62)
PIR sensor at $7.62. It is a 2-pack that sees motion up to 7m away, with a 0.3 to 18 sec delay.
MQ-2 Smoke & Combustible Gas Sensor Module ($5.81)
MQ-2 sensor at $5.81. It detects smoke and gas from 300 to 10,000ppm with a 5V heater.
Arduino Nano 3.0 Compatible Development Board, Type-C USB, ATmega328PB, CH340C ($10.96)
Arduino Nano 3.0 board at $10.96. It carries an ATmega328PB chip with a CH340C USB-serial chip and Type-C USB.
Shop the full range: Arduino-Compatible Boards at Quality RC Parts. See also: Related guide.
Frequently asked questions
Which Arduino board should a beginner pick for a robot?
The UNO R3 at $9.27 for bench work, or the Nano at $10.96 for a small chassis.
How far does the line sensor read?
The TCRT5000 reads 1 to 25mm with a digital output. A 4-pack costs $7.02.
How far does the PIR sensor see?
Up to 7m inside a cone under 120 degrees. A 2-pack costs $7.62.
Can a board pin power a servo?
No. Power servos from a separate 5V to 6V supply with a common ground.
Sources
Last updated: November 10, 2026.