Testing Distance Sensors

I’m working on a project involving the need to precisely move a tool based on the measured distance to an object. Okay, yeah, it’s a CNC mill. Anyway, I’d heard of time of fight sensors and decided to get one to test out, but also to be thorough I wanted to include other distance sensors as well: a Sharp digital distance sensor as well as a more sophisticated proximity/light sensor. I plugged them all into a breadboard and ran them through their paces, using a frame built from aluminum beams as a way of holding the target materials at a …read more http://pje.fyi/PfPf25

Paul Jacob Evans

Everything You Need To Know About Logic Probes

We just spent the last hour watching a video, embedded below, that is the most comprehensive treasure trove of information regarding a subject that we should all know more about — sniffing logic signals. Sure, it’s a long video, but [Joel] of [OpenTechLab] leaves no stone unturned.

At the center of the video is the open-source sigrok logic capture and analyzer. It’s great because it supports a wide variety of dirt cheap hardware platforms, including the Salae logic and its clones. Logic is where it shines, but it’ll even log data from certain scopes, multimeters, power supplies, and more. Not …read more http://pje.fyi/PbXCc0

Paul Jacob Evans

RoGeorge Attacks a Pulse Meter

The “Crivit Sports” is an inexpensive chest-strap monitor that displays your current pulse rate on a dedicated wristwatch. This would be much more useful, and presumably more expensive, if it had a logging option, or any way to export your pulse data to a more capable device. So [RoGeorge] got to work. Each post of the (so-far) three-part series is worth a read, not the least because of the cool techniques used.

In part one, [RoGeorge] starts out by intercepting the signals. His RF sniffer? An oscilloscope probe shorted out in a loop around the heart monitor. Being able to …read more http://pje.fyi/PYTvhL

Paul Jacob Evans

Using a Decade Counter to Make LEDs Flash

[Andrea De Napoli] created a LED display consisting of a half-dozen LEDs connected to the inverted signals of a CD4017 decade counter, giving the effect that a dark LED is running back and forth. The CD4017 works by activating 10 outputs, one at a time, as controlled by a clock signal sent to pin 14.

The first and last LEDs are lit by outputs 0 and 5 with the help of a PNP transistor and a 12K resistor. The middle four LEDs are switched by two outputs each and go dark when one of them goes high. [Andrea] really delves …read more http://pje.fyi/PYTG4N

Paul Jacob Evans

The Ultimate Breadboard – a prototyping station that has it all

[Claudio] was working on a homebrew oscilloscope project when he started thinking about how unsuitable a standard breadboard is for a large-scale project. Rather than adding components on top of components until they became what he lovingly calls a “fragile, unforgiving crapstack”, he decided to build himself the Ultimate Breadboard.

He packed so much into his design, that it’s honestly hard to know where to begin describing it. Aside from an appropriately large breadboarding surface embedded in the center of the console, he added a power supply to the left hand side, which sits just below an Avr-Net-IO board. The …read more http://pje.fyi/PXf4B6

Paul Jacob Evans

Three Thumbs, Way, Way Up!

At least one in their lives — or several times a day — everyone has wished they had a third hand to help them with a given task. Adding a mechanical extra arm to one’s outfit is a big step, so it might make sense to smart small, and first add an extra thumb to your hand.

This is not a prosthetic in the traditional sense, but a wearable human augmentation envisioned by [Dani Clode], a master’s student at London’s Royal College of Art. The thumb is 3D-printed out of Ninjaflex and mounted to a printed brace which slides over …read more http://pje.fyi/PVzxQy

Paul Jacob Evans

Let’s Play Spot The Fake MOSFET

Recently, the voice push to talk circuit in [Ryan]’s BITX40 radio was keyed down for a very long time. Blue smoke was released, a MOSFET was burnt out, and [Ryan] needed a new IRF510 N-channel MOSFET. Not a problem; this is a $1 in quantity one, but shipping from Mouser or Digikey will always kill you if you only buy one part at a time. Instead, [Ryan] found a supplier for five of these MOSFETs for $6 shipped. This was a good deal and a bad move because those new parts were fakes. Now we have an opportunity to play …read more http://pje.fyi/PVqjBm

Paul Jacob Evans