In this article I’ll walk you through how to select the hardware for an Arduino Uno Robot project.
This is part of my free course: How to Build an Arduino Uno Robot. Which I’m making available as a series of blog posts.
Step 1. Define the project goals
When building a robot, the first thing that you should do is define your project goals.
The goals for this project are to build a robot that:
- Uses an Arduino Uno for a brain
- Does not require a soldering iron
- Only requires a screwdriver and a pair of pliers to assemble
- Uses a snap on Arduino Shield to drive the motors
- Only has two motorized wheels
- Can be programmed with free, downloadable software
- Can be powered by rechargable NiMH batteries
- Is relatively inexpensive to build
- Can run a motion loop to prove that the hardware is working
Step 2. Define the hardware and tools needed
For any electronics project you should define a BOM (Bill of Materials). In other words, a list of parts.
Based on the requirements, you will need the following parts and tools:
- Robot Chassis
- Arduino Uno
- Arduino Uno Motor Shield
- Battery Holder
- NiMH rechargable batteries + charger
- On / off switch
- A small screwdriver
- A pair of pliers
- A wire stripper
- Zip ties
Step 3. Select a robot chassis kit
You will need a robot chassis that includes two DC (direct current) motors.
Here is a table that will help you avoid buying the wrong type of chassis:
|Motor Type||Good for this project?|
Only DC motors will work. Otherwise you will need to supply different or more drivers. In some cases even different power supplies.
What to look for in a chassis
The robot chasis that you select should have two DC (Direct Current) motors that have wires attached.
The wires are sometimes referred to as “attached” or “soldered” (or “welded” when poorly translated).
The kit itself should be easy to assemble. Some even come with their own small screw driver.
You don’t need a chassis kit that already has an Arduino Uno - unless you see one that you like.
Universal or Caster Wheels
A robot chassis that comes with only two wheels needs a third wheel to keep it from dragging. Most chassis’ have either a universal wheel (a ball in a holder) or a caster. I prefer a chasis with a universal wheel. But if you see an inexpensive chassis that uses a caster wheel that should work too.
Some universal wheel chassis’ have the wheel on the front and the back for stability. I just use one and and distribute the battery weight over it to keep the robot balanced.
If later you want to add a second universal wheel, you can buy several in one package.
I like a tank based chassis. But be aware that some (not all) can be a pain to assemble. If you do go with a tank chasis, make sure that it only uses two DC motors. Some have four. Which is fine. But won’t work with the code for this project.
The motor driver board that I’m going to select will support four DC motors. But for your first robot project, I would recommend starting with just two.
Here are some of the DC motor chassis’ that I own that only use two motors:
|Robot Chassis||Type||Easy to assemble|
|Bonatech||Two Wheels + Universal Wheel||Yes|
Step 4. Select a robot brain
For your first project I recommend starting with an Arduino Uno because it:
- is very popular with beginners
- is inexpensive
- is easy to program
- has motor shields that can snap on top of it
- can run on rechargable batteries
What to look for in an Arduino Uno
When you buy an Arduino Uno you should look for the following:
- a popular original or clone board
- fully assembled (labeled “with headers” and they are soldered in place)
- comes with a cable
You can buy an Arduino Uno direct from Arduino or you can buy a clone.
Here are some of the ones that I have used:
|Arduino||Uno WiFi R2 (Recommended)|
|Arduino||SMD Uno 3|
Why use the WiFi board?
For the first project I’m just going to show you how to create a robot that goes through a motion loop. When you turn the robot on, it will repeat a pattern to verify that the motors are working. You won’t need a board with WiFi capabilities for that. But in later articles I plan to show you how you can control the robot through WiFi. So you have two choices:
- Use an Uno WiFi R2 now
- Use an Uno 3 now and swap in an Uno WiFi R2 later
Since everything in this project just snaps in or screws in to place, doing the swap will be relatively easy.
Step 5. Select a motor driver
There are several motor drivers that I could have gone with. Here are my thoughts on some of the more popular ones.
|V2||Best choice (Recommended). Uses TB6612 chips. Can support up to 4 motors for future projects. Extends Arduino Uno headers for expansion.|
|L298N||Doesn’t snap on to Arduino. Would require extra wires and mounting.|
|Arduino Motor Shield||Official shield|
|V1||Older model. No header extensions.|
Why recommend the V2?
I’m recommending the V2 because it uses a popular chipset and extendable headers. That will allow me to show you in later articles how to attach additional hardware to your robot.
Step 6. Select a battery holder
The chassis that I use comes with a battery holder for two 18650 lipo batteries. But I prefer to power my robots through 6 AA NiMH batteries. You can order NiMH batteries online or find them at most grocery and department stores. You can even buy sets that come with their own wall charger. Be sure to buy batteries and the chargers from a known brand for a better guarantee of safety.
Step 7. Select an on / off switch
I find it very handy to have an on / off switch. Otherwise you have to fumble with the robots battery pack whenever you power it up or down.
Step 8. Finalize the Bill of Materials
Based on all of the above, here is my recommended Bill of Materials (AKA parts list) for an Arduino Uno beginner robot project:
If a product is listed as currently not available, see if you can find something similar.
|A small screwdriver||Included with the recommended chassis|
|A pair of pliers||Available at most hardware stores or departments|
|A wire stripper||Available at most hardware stores or departments|
|1/8” zip ties||Available at most hardware stores or departments|
In this article you learned how to:
- Define a robot projects hardware goals
- Select a robot chassis kit
- Select an Arduino board for a robot project
- Select a motor driver board for a robot project
- Finalize a project Bill of Materials (AKA BOM, AKA parts list)
Now that you’ve selected parts for the robot, see my article Arduino Uno Robot Hardware Assemble for instructions on how to build it.
- How to Build an Arduino Uno Robot (Free Course)
- Arduino Uno Robot Class Library Setup
- Arduino Uno Robot Hardware Assemble
- Arduino Uno Robot Motion Loop
- Motor Driver Tutorial (L298N)
- How to Read an Arduino Nano 33 IOT IMU
About the Author
Mitch Allen has worked for software companies in Silicon Valley, along Boston’s Route 128 and in New York’s Silicon Alley. He currently works for a robotics company in Massachusetts.