The resurgence of Battlebots in the States and Robot Wars in the UK reignited my love of combat robotics. So I found a local group of bot builders and dived right in.

We fight at the UK ant weight scale (150 gram weight limit) and I quickly realised the traditional way to build a bot involved RC gear: an expensive RC transmitter, a bulky or expensive receiver and ESCs (electronic speed controllers) which are magic boxes that can handle way more current than is necessary for a bot of this size.

Having used Arduino in the past I wanted to try and do things differently and set myself a goal of an Arduino system that can receive a combat legal signal and control two drive motors for around USD$5 (half the cost of a cheap ESC)

To help achieve this goal I remixed this RC car instructable, reducing the weight/cost of the receiver and generating 4 PWM signals to run a cheap h-bridge chip

This instructable will focus on the Arduino control system but I'll add additional information to help new people build their first bot


Even at a small scale combat robot building/fighting can be dangerous, undertake at your own risk

Step 1: What You Need


For the control system:

For the rest of a basic wedge bot:

For a basic controller:


  • Screw driver
  • Soldering iron
  • Pliers
  • 3d printer (optional, but it makes life easier)

*when looking at h-bridge modules, look for a module with all 4 signal inputs next to each other, this will make it easier to attach to the Arduino later

**check out the final step for some tips on picking motor speeds

<p>Very nice! Well done instructable and nice little beginner antbot design. Thanks for including all sources so that others can easily replicate the design. I have a pet peeve against instructables that &quot;use a motor from a printer I had laying around&quot; that makes it difficult to copy.</p><p>The only suggestion I have to mention as an &quot;upgrade&quot; would be to reduce weight by cleaning up wiring, etc, and then re-add that weight in strategic locations (lip of the wedge, at each wheel, etc) to improve it's attack capability.</p><p>Thanks for the extra motor information as well. Sometimes, what seems so complicated for someone looking to make their own can easily be explained by someone like yourself, but is not always clearly communicated. Your motor info is clear, concise, and helpful.</p>
<p>Thanks! I wanted to make it as easy as I could, because I know that I had a lot of questions a year ago when I got started. </p>
<p>Well done!</p><p>I suggest one improvements. Move the NRF24 pins from D9 and D10 to D7 and D8, so you free the hardware pwm pins. Remove the software pwm library. Use D5 and D6 for leftFor and LeftBack. Use D9 and D10 for rightFor and rightBack. Use digitalWrite on these pins instead of SoftPWMSet.</p><p>ManiacBug library is very old, there is a new one but it is slighty different and maybe it doesn't work for you.</p>
<p>Thanks for the tips. I was new to the NRF24 going into this project and every project I found used D9 and D10.</p><p>On top of that, using the software PWM library allowed me to use 4 adjacent pins so the H-bridge simply slots into place and is not going to move. In a high impact environment I feel that ruggedness is more important then the nanosecond saving using digitalWrite would provide (especially as my reaction time is the significant delay in the system)</p>

About This Instructable




Bio: An Aussie guy with a passion for teaching STEM and tinkering with all things electrical, especially robotics.
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