Introduction
I have always been fascinated by robots and wanted to build my own. Recently, I came across small Arduino boards and realized I could make a mini robot that actually does something useful - clean my floors! In this article, I will walk you through the full process of constructing a pocket-sized Arduino robot vacuum from start to finish.
Choosing the Right Arduino Board
The first step is picking the right Arduino board to power your robot. Here are some options to consider:
Arduino Nano
The Arduino Nano is a compact, breadboard-friendly board that provides ample processing power in a tiny package. It's also very affordable. The small form factor makes it perfect for building miniature robots.
Arduino Micro
Slightly larger than the Nano, the Arduino Micro offers more I/O pins and flash memory. This comes in handy if you want to add more sensors or complex routines to your robot. The tradeoff is size - the Micro won't fit into super tight spaces.
Arduino Pro Mini
The Pro Mini strips down the Arduino board to its bare essentials. Extremely compact, it's great for squeezing into tiny robots. However, it lacks builtin USB connectivity for programming and requires additional hardware.
For my pocket floor cleaning bot, I went with the Arduino Nano for its balance of small size, pin availability, and ease of use.
Assembling the Base Chassis and Motors
The base chassis provides a framework to mount all the components. For a miniature bot, you'll want something lightweight yet sturdy.
Plastic and acrylic sheets make excellent chassis material. I cut and bent a simple two-wheeled chassis out of thin acrylic. 3D printing a base is also an option.
Motors drive the robot and allow it to move around. For a small Arduino robot, miniature brushed DC motors work well. I used micro metal gear motors with built-in wheels, which simplified the drive train.
I secured the motors to the chassis using small screws and brackets. Getting the right spacing between the wheels is key for stability and maneuverability.
Adding Sensors to Detect Obstacles
The robot needs to know where it is going to navigate and avoid obstacles. For this, I added several distance sensors.
Sharp IR Sensors
Sharp IR sensors work by emitting an infrared light beam and measuring the reflection. They're inexpensive and easy to interface. I mounted sensors on the front, sides, and back of the chassis.
Ultrasonic Sensor
An ultrasonic sensor uses high frequency sound to determine the distance to objects. I added one facing forward for better obstacle detection. The wide beam complements the IR sensors' narrow points.
Connecting the Sensors
I soldered wires from the sensor pins to the Arduino so I could read their values in code. Pay close attention to the pinouts when connecting them. The sensors run at 5V, so I powered them directly from the Arduino 5V pin.
Programming the Arduino
The real brains of the robot comes from the Arduino sketch - the program I wrote to make it work autonomously.
Importing Libraries
I imported the Servo and NewPing libraries to interface with the ultrasonic sensor and control the brush motor.
Setup and Loop
In setup(), I initialized the sensors, motors, and other components. Loop() contains the main logic loop that runs continuously on the Arduino.
Reading the Sensors
Within loop(), I used functions like pulseIn() and ping() to take distance readings from the sensors. I stored them in variables for use in the code.
Driving and Steering
Based on the sensor values, I drove the motors forward or backward using digitalWrite() and analogWrite() to control speed and direction. I also steered left/right by running the motors at different speeds.
Avoiding Obstacles
By checking distance thresholds, I could detect obstacles and trigger avoidance routines, like backing up and turning away. The ultrasonic sensor gave advanced warning of objects ahead.
Adding a Brush and Dust Bin
To actually clean, I needed a brush to sweep debris and a dust bin to collect it.
Brush Module
I got a small motorized brush module made for auto vacuum robots. It sweeps dirt and dust into the path of the suction. I mounted it up front and drove it with a separate Arduino servo pin.
Dust Bin
Below the brush, I attached a small container to hold the sucked up debris. I 3D printed a bin that sits just above the ground to maximize dirt collection. Emptying it is as easy as removing the container.
Powering the Robot
The Arduino needs a portable power source. I used a small lithium polymer battery to power both the Arduino and the motor/brush modules.
A battery holder secured it in place. I added a switch to cut power when not in use. The battery could run the robot for 15-20 minutes before needing a recharge.
And that covers the full build process! Thanks for reading. Let me know if you have any other questions about constructing tiny robots with Arduinos!