Saturday Update: Wheelchair Hacking and Maths

Posted on by burf2000

Hello and welcome to another Burf Update, it’s odd doing it on a Saturday night but there is quite a lot to report (if I can remember it all)

Maths
I have gone back to Khan Academy and have redone 3rd Grade (lol), I am now 46% through 4th Grade and plan to do all the Maths Khan have to offer 🙂 I already have over 500,000 points on the site. The aim is to at least understand some A-level maths by mid-next year.

Wheelchair Hacking

So finally I have started to try and work out how to hack the joystick on the Electric wheelchair. I have not succeeded yet after many hours but I have learned so much. If I was brave enough to cut the wires I could really see what was going on inside. I believe it works using a microchip that detects magnetic forces (A Youtube video explained it) however he was trying to reuse the stick, not mimic it to do remote driving.

Wheelchair joystick controller opened up next to an Arduino
Wheelchair joystick wired up for testing on the desk
Electric wheelchair base with its wiring exposed
Handheld oscilloscope probing the wheelchair controller signals

I got to learn quite a bit and even used my oscilloscope 🙂 However, I have decided that it would be easier to create something that controlled the joystick via servos so that I do not need to break anything. I have started learning Autodesk Fusion 360 to design it and then 3D print the new mechanism.

I have bought a new tool that allows me to measure stuff precisely so that I can design it properly

Motor shaft being measured with digital callipers

I have also built a little pillar drill to allow me to drill stuff out (a random thing I found in the garage)

Small benchtop pillar drill

Hoverboard goes boom

So I had a spare hoverboard to take apart as I wanted to see if I could control it with an Arduino. To do this I needed to soldier a connector onto it. Sadly though I unplugged it, the capacitors must have still had energy in them as they made a rather large spark and blow the board. I am now trying out a Scooter motor controller off eBay 🙂

Hoverboard wheel motor and controller boards laid out on the table

It feels like I have done more electronics in the last 5 days than in the last 5 months which is rather exciting 🙂

Garage

It’s clearer than it’s been for a long time, I have a lot of LEGO to sort but making good progress on this.

Application of Robotic Tools Course

Completed, not a great course but at least it’s finished

ROS

I have started playing with ROS (Robotics Operating System), just a bit of a refresher as I plan to move to ROS 2.

I hope to either have a hacked Wheelchair or a hacked hoverboard working for the next update 🙂

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