Clever Circuit Makes Exercise Slightly Less Boring

We say this with the greatest respect, but [Joel] — your exercise routine is horrible! Kudos for getting up and doing something, but 108 trips up and down the stairs? That sounds like torture…

Celebrating The [Jack Ells] Automatic Photometric Telescope

Here at Hackaday, we take pride in presenting the freshest hacks and the best of what’s going on today in the world of hardware hacking. But sometimes, we stumble upon a hack from the past so…

Homebrew Computer From The Ground Up

Building a retro computer of some sort is a rite of passage for many of us, with some building replicas or restorations of old Commodores, Ataris, and other machines from decades past. Others go ev…

This Block Of Rubber Can Count To Ten

Complex behaviors can arise from simple mechanics, and that’s demonstrated by a block of rubber that acts as a counter. The block contains beams, and by controlling how the block is compresse…

Op-Amp Challenge: A Logic-Free BCD

Of digital electronics, a wise man once said that “Every idiot can count to one.” Truer words have rarely been spoken, because at the end of the day, every digital circuit is really jus…

Automatic Coin Sorter Brings Order To Your Coin Jar

Few things hold as much promise as the old coin jar. Unfortunately, what’s generally promised is tedium, as one faces the prospect of manually sorting, counting, and rolling the accumulated c…

To Turn An ATtiny817 Into A 150MHz Counter, First Throw Out The Spec Sheet

One generally reads a data sheet in one of two ways. The first is to take every spec at face value, figuring that the engineers have taken everything into account and presented each number as the a…

Empty Spools Make Useful Tools, Like Counters

What’s the deal with getting things done? There’s a Seinfeld anecdote that boils down to this: get a calendar, do a thing, and make a big X on each day that you do the thing. Pretty soo…

A Nixie Clock, The Hard Way

Notice: no vintage Hewlett Packard test equipment was harmed in the making of this overly complicated Nixie clock. In fact, if anything, the HP 5245L electronic counter came out better off than it …

Homebrew ROM Reader Saves Data From A Vintage Minicomputer

Have you ever heard of a Centurion minicomputer? If not, don’t feel bad — we hadn’t either, until [David Lovett] stumbled upon a semi-complete version of the 1980-ish mini in all …