Using the 3pi to solve a wall maze?

I’ll preface this post by saying I’m a software guy looking to get my hands on a robot that has the hardware necessary to traverse a walled maze. I have very little electronics experience but I’m happy to remove/add parts so long as there’s no soldering required. I don’t know if what I’m after is even possible without soldering by that’s part of what I want to ask.

I’m after something like this:

I’ve searched as much as I can, but the 3pi is the only pre-built candidate that even comes close to what I’m after. PICAXE stuff is BASIC only which isn’t good for me as I’m looking for C/C++ programmable stuff. So my questions are:

1. Is it possible for me to get a robot like the one in the video without any soldering?
2. If it is possible without soldering, what parts would I need and is there any sort of assembly guide for electronic newbies I could use?
3. If it isn’t possible without soldering, is there any solution that gets near to the robot in the video that I could obtain without soldering?


You should be able to modify the 3pi or the Zumo Robot for Arduino with some optical range finders to make a robot like that. However, doing so would involve some soldering.

If you are up for learning how, soldering can be a very useful skill to have for hobby robotics. There are plenty of useful tutorials and resources online that can help. You might check out “Adafruit’s Guide to Excellent Soldering” or some of these “Basic through-hole soldering tutorials”.


Alright, I think I can find a guy to help me out with the soldering and assure me I’m doing it properly, but I’d like to make sure I’m 100% certain on the parts before I order them.

So, to achieve something like the robot in the video, I’m guessing I need to order the following parts:
3 x
2 x
2 x

Unsure if I will need to purchase any Micro Metal Gearmotors or not.

Also, I happened to find the video creator on these forums!

This helps, but also makes me worried that I’ll end up getting stuck and not being able to finish building it as people are pretty impressed by it.

But anyway, I’m going to assemble some assembly documentation as best I can based on Terry’s instructions, make sure I have all the right parts required and then take them to somebody who knows what they’re doing to assist me in putting it together. So yeah, for now, just some help on buying the right stuff will help a lot.


Those digital and analog Sharp distance sensors should work fine with the 3pi; however, please note that since the 3pi comes with the motors already soldered in, it does not support encoders without heavy modification. If you are going to attempt this nontrivial modification to the 3pi to make it work with encoders, you might consider our newer Magnetic Encoder Pair Kit for Micro Metal Gearmotors. These encoders are meant to be soldered onto the back of the micro metal gearmotors with extended motor shafts, so you would need to replace the 3pi gearmotors with a version with an extended backshaft, which requires some soldering work. You can see some examples of this kind of 3pi modification in this form post titled “3pi with pololu encoders”. Please note that the modifications shown in that forum post use the optical encoders, which are slightly different, but are also attached to the back of the motor in the same way.

Also, since the 3pi has limited I/O pins available, I would suggest using a separate microcontroller board for processing some or all of these additional inputs. You might consider the m3pi Expansion Kit for this, which has a socket intended for an mbed development board.