Arduino Uno Robot Hardware Selection (8 Steps)

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 Hardware

  • Robot Chassis
  • Arduino Uno
  • Arduino Uno Motor Shield
  • Battery Holder
  • NiMH rechargable batteries + charger
  • On / off switch

Tools

  • 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?
DC Motor Yes
Servo motor No
Stepper motor No
Brushless motor No
AC motor No

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.

Tank Chassis

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
Defender Tank Treads No

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:

Manufacturer Board
Arduino Uno WiFi R2 (Recommended)
Arduino SMD Uno 3
Sunfounder Uno 3
Elegoo 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.

Motor Driver Comments
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:

Robot Hardware

If a product is listed as currently not available, see if you can find something similar.

Description Product Link
Robot Chassis BONATECH Two Wheels Smart Car Chassis
Alternate motors 4 pcs TT DC Gearbox Motor Dual Shaft 3-6V Gear Motor for Arduino Smart Car Robot You can use the motors that come with the chassis. I prefer to put them aside for other projects and use these motors with zip tied leads and DuPont connectors.
Arduino Uno Wifi R2 Arduino UNO WiFi REV2 [ABX00021]
USB-A cable AmazonBasics USB 2.0 Printer Cable - A-Male to B-Male Cord - 6 Feet (1.8 Meters), Black If you have a USB-A connector on your laptop, get this cable to connect it to the Arduino Uno
USB-C cable CableCreation USB C Printer Cable 6.6ft, USB C to USB B 2.0 Cable, Compatible with MacBook Pro, HP, Canon, Brother, Samsung Printers etc, 2M/Black PVC with Aluminum Shell If you have a USB-C connector on your laptop, get this cable to connect it to the Arduino Uno
Arduino Uno Motor Shield HiLetgo TB6612 Mosfet for Arduino Motor Shield V2
NiMH rechargable batteries with charger Energizer AA/AAA 1 Hour Charger with 4 AA NiMH Rechargeable Batteries (Charges AA or AAA Batteries in 1 Hour or Less) CH1HRWB-4
NiMH rechargable batteries Energizer Rechargeable AAA Batteries, 700 mAh NiMH, Pre-charged, Chargeable for 1,000 Cycles, 8 Count (Recharge Universal)
Battery Holder 6 AA Battery Holder With 2.1mm x 5.5mm Connector 9V Output 2 Pack by Corpco
Female 2.1mm x 5.5mm Adapter Connector 10 Male and 10 Female 12v DC Power Jack Adapter Connector for Led Strip CCTV Camera
On / off switch 10pcs Mini Toggle Switches ON/Off SPST with Pre-soldered Wires for Truck,Car,Industrial Equipment,Emergency Lighting
22 AWG wire Fermerry 22 AWG Silicone Wire 6 colors 50ft each 22 Gauge Stranded Tinned Copper Hook up Wire Kit (6 Colors 50 FT each, 22AWG) This package comes with zip ties
Cable Ties Superun 50 Pcs Multi-Color 6 Inch, 8 Inch, and 10 Inch Assorted Reusable Cord Organizer Cable Ties, Fastening Hook and Loop Wire Wrap Management To keep the battery pack from flying out at high speed, you should get some cable ties to wrap around the pack

Tools

Description Product Link
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

Conclusion

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.



About the Author

Mitch Allen works for a robotics company in New England.