Tag Archives: electronics

Debouncing fun with Schmitt triggers and capacitors

You simply can’t trust switches. You think they’re either on or off, but the truth is that, in getting from one state to the other, they can change their mind many times. This is a phenomenon known as switch bounce and it happens because switches aren’t perfect. Just at the point where they are making or breaking contact, certain mechanical… Read more »

Epson MX-80 Part 1 – resurrecting an old friend

It’s hard to lose an old friend with whom you’ve shared more than a  third of a century’s worth of experiences. I’ll never forget the day it happened. I heard a coughing, spluttering noise, turned around and, sure enough, smoke was pouring out of the printer. And not just any old printer – my trusty Epson MX-80F/T III, the first… Read more »

Serial to parallel the hard way

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I kind of miss making hard copies of my program listings on a dot matrix printer. There’s something contemplative and satisfying about waiting for the printer to finish its buzzing and chattering so that you can pore over the code and find that bug. Also, printouts on continuous listing paper with holes down the sides feel like real computing. It… Read more »

Hacking a film scanner

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I’m building a rig to digitise my large selection of 35mm transparencies and negatives and in the process I’ve encountered what could be one of the worst electronic products I’ve ever bought. And in the spirit of the ineffable Big Clive, I thought I’d share my adventures in taking it apart. In some ways this belongs over on my photography… Read more »

Fault finding: the aha! moment

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Well, maybe not so much aha! More like FFS. Weird as it sounds, debugging errors is one of the things I enjoy about both coding and electronics. I’m an amateur in both fields and waste little time on planning my projects. I prefer just to delve right in. Rather than sketch out a circuit first, for example, I just get… Read more »

Dreambox: change of plan

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Okay, so here’s a tip for anyone who, like me, prefers to make up their electronics projects as they go along – who simply doesn’t have time for all that planning and designing nonsense. Buy yourself a desoldering station. Seriously – buy it before you even buy a soldering iron, just to be safe. A quick recap: I decided that… Read more »

Dreambox: switching to plan A

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Planning is a good thing. Having your project mapped out before you start saves time and avoids wasteful detours and last-minute kludges. I should definitely do that some day. My approach to electronics is the same as my approach to writing software: just get started – it’ll all work out somehow. Luckily, I don’t write code or build electronic devices… Read more »

PiDP: The next project

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Well, this is exciting. My PiDP kit has just arrived from Oscar Vermeulen. I couldn’t resist pealing back the protective cover on the acrylic front panel. It looks fantastic – and will be so much better when it has all the blinkenlights. I haven’t decided yet whether I will use one of the Raspberry Pi A boards I have lying… Read more »