Pocket-Sized Multiduino Does it All

How many times have you wished for a pocket-sized multimeter? How about a mini microcontroller-based testing rig? Have you ever dared to dream of a device that does both?

Multiduino turns an Arduino Nano into a Swiss Army knife of portable hacking. It can function as an analog multimeter to measure resistance, voltage drop, and continuity. It can also produce PWM signals, read from sensors, do basic calculator functions, and display the health of its rechargeable battery pack.

Stick a 10kΩ pot in the left-side header and you can play a space shooter game, or make line drawings by twisting …read more http://pje.fyi/QKxtWd

Paul Jacob Evans

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Edgytokei: Time On The Edge

Taking inspiration from Japanese nunchucks, [ekaggrat singh kalsi] came up with a brilliant clock that tells time using only hour and minute hands, and of course a base for them to sit on. The hands at certain parts of the hour seem to float in the air, or as he puts it, to sit on their edges, hence the name, the Edgytokei, translating as “edge clock”.

The time is a little difficult to read at first unless you’ve drawn in a clock face with numbers as we’ve done here. 9:02 and 9:54 are simple enough, but 9:20 and 9:33 can …read more http://pje.fyi/Q9ZBtk

Paul Jacob Evans

Make A Cheap Muon Detector Using Cosmicwatch

A little over a year ago we’d written about a sub $100 muon detector that MIT doctoral candidate [Spencer Axani] and a few others had put together. At the time there was little more than a paper on arxiv.org about it. Now, a few versions later they’ve refined it to the level of a kit with full instructions for making your own under the banner, CosmicWatch including PCB Gerber files for the two surface mount boards you’ll need to assemble.

What’s a muon? The Earth is under constant bombardment from cosmic rays, most of them being nuclei expelled from supernova …read more http://pje.fyi/Q37PWG

Paul Jacob Evans

DIY VT220 Keyboard

There’s always been interest in the computers of old, and people love collecting and restoring them. When [peterbjornx] got his hands on a DEC VT220 video terminal, it was in good shape – it needed a bit of cleaning, but it also needed a keyboard. [Peter] couldn’t afford to buy the keyboard, but the service manual for it was available, so he decided to convert a modern keyboard to work with his new terminal.

The original keyboard for the VT220 is the LK201. This keyboard communicates with the terminal using 8-N-1 (eight data bits, no parity, one stop bit) over …read more http://pje.fyi/PdrY1S

Paul Jacob Evans

Modern DIY FM radio

Back in the day, building a DIY radio was fun! We only had to get our hands at a germanium diode, make some coils, and with a resistor and long wire as an antenna maybe we could get some sound out of those old white earplugs. That was back then. Now we have things like the Si4703 FM tuner chip that can tune in FM radio in the 76–108 MHz range, comes with integrated AGC and AFC, controlled by I2C, as well as a bunch of other acronyms which seem to make the whole DIY radio-building process outdated. The challenges …read more http://pje.fyi/NkjVBr

Paul Jacob Evans