James Stanley

Posts tagged 'electronics'

Another new switch tester, test results, and thoughts on the keyboard design »

Wed 15 July 2020

Just an update on the keyboard switch project. I've built the new 10-way testing machine, ran a (somewhat inconclusive) test to work out the best thickness for the leaf springs, and thought a bit on how I'm going to design the actual keyboard. Read more »

I made a macro keypad with 3d-printed switches »

Mon 6 July 2020

Latest on the 3d-printed keyboard switch project: I've reached a switch design that I think is probably reliable enough, and I've put 3 of them together to form a macro keypad just to see how it all goes together before I commit to a full keyboard. I don't have a number for how many presses the switch lasts, other than to say that the motor on the testing machine stopped working before the switch did (after about 250,000 presses). Read more »

Keyboard switch progress & test results »

Thu 25 June 2020

Status on the 3d-printable keyboard switch is that the latest test managed 110,000 presses before failure, on the spinning cam tester. Read more »

A better automatic keyboard switch tester »

Sat 20 June 2020

Since breaking the last switch, I re-printed the same design in PETG to see if it would last any longer, and it did! It reached over 100,000 presses under the gentle testing regime without showing any failures, a big improvement over failing at 13,907. Read more »

I broke my first 3D-printed keyboard switch »

Tue 16 June 2020

Overnight I did my first test of a homemade keyboard switch on the automatic tester. The spring in the switch broke after 13907 presses. That makes Martin our competition winner, with a guess of 10000. Read more »

Automatic keyboard switch tester »

Sun 14 June 2020

I'm working on designing an open source 3D-printable keyboard switch at the moment, with a view to eventually making my own mechanical keyboard using minimal off-the-shelf components (just an Arduino, wire, and diodes, with homemade parts for switches, keycaps, and case). I have not made a keyboard yet, but yesterday I made a device to test how many presses a switch can withstand before it stops working. Read more »

Autopatzer: my automatic chess board »

Wed 6 May 2020

My automatic chess board (the "Autopatzer") has reached the point where last night I was able to play its first online game against a real person using lichess's Boards API. Read more »

Automatic chess board design »

Sat 14 March 2020

Lichess has recently released a Boards API, allowing anybody to interface a physical chess board with lichess in order to play online games using an automatic board. I previously thought about implementing my Strange Chess Clock using an automatic board, but never got round to it. With lichess now supporting online play with an automatic board, it's hard to justify not making one! Read more »

I built an antweight combat robot »

Mon 27 January 2020

If you've ever seen Robot Wars or BattleBots, you'll know what a combat robot is. An antweight combat robot is the same concept, except it has to weigh no more than 150g and fit inside a 4-inch cube. I've built one, called "Wedge of Glory", and have my first competition this weekend! Read more »

Design and Implementation of a Z80 Computer Front Panel »

Tue 12 November 2019

I designed and built a front panel for my RC2014. It allows you to view and alter the contents of memory, read and write to IO devices, and single-step through instructions. The RC2014 backplane basically just puts the Z80 CPU pins directly on the bus, so the same panel would work unmodified against almost any Z80-based computer, as long as you broke out the bus onto the 60-pin ribbon cable. Read more »

The RC2014 Z80 Microcomputer »

Mon 21 October 2019

I recently came across the RC2014. It is a simple computer sold in kit form, and using a Zilog Z80 CPU. Read more »

My Arduino-based industrial process controller »

Sun 1 September 2019

For my 3d metal printing project, I need the sintering furnace to stick to a pre-defined temperature profile. Unfortunately, the controller that my furnace came with only allows you to set a constant temperature. It maintains a constant temperature very well, but the operator frequently has to manually update the temperature in order to stick to the defined profile. Read more »

How to make a rev limiter with an Arduino »

Mon 22 July 2019

My racing mower has a tendency to over-rev on long straights. To avoid damaging the engine, we have been lifting off the throttle, but a more reliable solution would be an electronic rev limiter. I did buy a commercial rev limiter made by AccuSpark, but was unable to fit it to my mower because the AccuSpark unit needs access to both sides of the ignition coil, and my ignition coil is inaccessible, inside a black box with all the other ignition electronics. So my solution was to make a rev limiter with an Arduino. Read more »

My PiKon telescope hardware »

Mon 3 December 2018

Since the last post I've been working on the hardware of my telescope. I think the hardware is basically done, I just have a bit more software to write, and then need to wait for a convenient and cloud-free night in which to try it out. Read more »

What's inside an HSBC SecureKey? »

Thu 12 July 2018

You've probably seen an HSBC SecureKey. It's a 2-factor authentication device for online banking. I was given one because the previous owner had started using the bank's smartphone app and no longer needed the SecureKey. It looks like this: Read more »

My homemade ebike control panel »

Fri 1 June 2018

I wrote before about dismantling the control panel from my ebike to find out how it works, and had some ideas for an improved design. Read more »

Reverse engineering an ebike 3-mode PAS LED panel »

Fri 11 May 2018

I bought an electric bicycle recently. It is an incredible machine, and I think everyone should get one. The thing I never liked about cycling is how tired you get going up hills, and the electric bicycle solves this problem without taking away any of the fun parts of cycling. A truly incredible machine. Read more »

How to control a digital speedometer »

Tue 12 December 2017

As part of my YX140 scooter project (now finished) I discovered that the scooter's speedometer is controlled digitally. There was a sensor in the original engine which generated pulses to signal the speed of rotation of the gearbox output shaft. The new engine has no such sensor, so I had to do a little electronics to make the speedo work. Read more »

Secrets of the Medtronic MyCareLink Patient Monitor »

Sun 4 December 2016

I have acquired a "Medtronic MyCareLink Patient Monitor 24950" and have been playing with it a little this weekend. It looks like this: Read more »