This article was last modified on 26 November 2016.

When I was trying to build my first robot with an Arduino UNO, I had a hundred questions that I had to find answers. Some of those questions were, “How much will cost me to build a mobile robot?” and, “What happens after the project is finished? Can I reuse the components?” and even, “What are the components with the best price – performance ratio?”

What means for you a cheap Arduino UNO project?

A project that’s worth $50?

$70?

$100?

Well, probably 10 out of 10 readers have a different opinion of what means a cheap project. Even so, in this article, I explore projects built with cheap components and parts, and stuff that can be found in almost any creation room of roboticists. More than that, you can reuse all of these components and parts to build new innovative robots.

If you do not have an Arduino UNO, you have to spend few dollars only to buy one. This will change a little bit the shopping list and the final price of the project.

With all these details in mind, I added to the below list more than 10 Arduino UNO projects that will not exceed the threshold of $100 in costs.

On the Internet are tons of Arduino projects and large communities of hackers and makers. At a click away, you can read how a hacker tries to hack a toy car, and in the next minutes, you can read about how a maker is using electric motors from a printer to build a robot. All of them are a good source of inspiration.

How simple is to build a walking robot?

That’ all I can say. Very simple. You can build a walking robot using four micro servos, a UNO board, a mini breadboard, cardboard parts, wires, glue, and few other components.

This simple bot can dance and walk around obstacles.

Using an Arduino, a GSM shield, few sensors, resistors, and many wires, you can build an alarm system able to arm or disarm your door/window via SMS message.

This project includes an Android smartphone and an Android application with a button for arming and disarming the system.

This is a three-wheeled robot programmed to do figures of 8 in forward and backward mode. The chassis is built from cardboard and lollipop sticks. The most expensive components are the motor controllers, electric motors, and the micro 9g servos.

This project is a four-wheels robot car remote controlled with a TV remote control. The project includes an Arduino UNO, two DC motors, IR receiver, an L293D motor driver IC, batteries, wires, a simple chassis, and wheels.

This project shows you how simple is to build intelligent machines with an Arduino microcontroller. This sorting machine is designed to separate colored candies by colors.

Without the Arduino UNO cost, the components needed to build this machine have a total cost under $100. In addition, there are few printed parts.

The sorting machine can handle up to 500 grams of colored candies at a speed of 80 pieces per minute.

This is a simple car built entirely from plywood and controlled wirelessly via an Arduino board. The project includes two chains to drive the wheels, batteries, electric motors, an Arduino motor shield, and several other components.

This cheap wheeled robot is engineered with an IR sensor to measure the distance between the robot and an object. Two servomotors are attached to the wheels and drive the robot.

Even the project seems complex, you can have a lot of fun building it with a cost less than one hundred dollars.

With a cost under one hundred dollars, you can build this two-wheeled robot able to keep its body in balance.

Rather than wires, screws, acrylic parts, the robot includes an Arduino UNO board and the sensor MPU6050 to control the balance.

The bot is controlled with an Android smartphone via a Bluetooth module attached to the robot.

With a wood chassis, a motor shield, two little wheels, batteries and wires you can build the mechanical Picasso of tomorrow.

This simple robot has attached a drawing pen on an arm that moves left and right to draw shapes.



With only one servomotor, a tilt sensor, and an Arduino UNO, you can build a rolling robot that can push itself forward.

This project shows you how to build a robot arm that cost less than one hundred dollars.

The designer uses six servomotors, lexan polycarbonate parts, and an ultrasonic sensor attached in front of the arm. The ultrasonic sensor helps the arm to react to movements in the environment.

You can make the project more complex by attaching a gripper to grasp objects.

This project shows you how to hack a car toy and transform it into an autonomous race car. All you need is an Arduino UNO, an ultrasonic sensor, and a motor driver.

The robot is working in four different modes. One mode leads the car to full speed, the second mode slows down the car when an object is detected, the third mode avoids the obstacle, and the fourth mode stops and reverses the toy car.