When Your Level Shifter Is Too Smart To Function

By now, 3.3V has become a comfortable and common logic level for basically anything you might be hacking. However, sometimes, you still need to interface your GPIOs with devices that are 5 V, 1.8 V…

Delays And Timers In LTSpice (no 555)

If you need a precise time, you could use a microcontroller. Of course, then all your friends will say “Could have done that with a 555!” But the 555 isn’t magic — it uses a…

Crank-Powered Train Uses No Batteries Or Plugs

The prolific [Peter Waldraff] is at back it with another gorgeous micro train layout. This time, there are no plugs and no batteries. And although it’s crank-powered, it can run on its own wi…

Do You Trust Your Cheap Fuses?

When a fuse is fitted in a power rail, it gives the peace of mind that the circuit is protected. But in the case of some cheap unbranded fuses of the type that come in kits from the usual online su…

Emergency DIP Pin Repair For Anyone

Who has not at some point in their lives experienced the horror of a pin on a DIP package breaking off? It’s generally game over, but what if you don’t have another chip handy to substi…

Extenders And Translators For Your I2C Toolkit

If you’ve ever been laying out a network I2C devices inside a project box or throughout your robot’s body, you’ll probably know that I2C is not without its pitfalls. But for many …

Espressif’s ESP32-P4 Application Processor: Details Begin To Emerge

Every now and then there’s a part that comes along which is hotly anticipated, but which understandably its manufacturer remains tight-lipped about in order to preserve maximum impact surroun…

Why Is My 470uF Electrolytic Cap More Like 20uF?

Inductors are more like a resistor in series with an ideal inductor, resistors can be inductors as well, and well, capacitors aren’t just simply a capacitance in a package. Little with electr…

Drop-In Switch Mode Regulators

Perhaps the simplest way to regulate a DC voltage is using a voltage divider and/or an active device like a Zener diode. Besides simplicity, they have the additional advantage of not being particul…

This Air Particulate Sensor Can Also Check Your Pulse Rate

The MAX30105 is an optical sensor capable of a great many things. It can sense particulate matter in the air, or pick up the blinking of an eye. Or, you can use it as a rudimentary way to measure y…

An ASIC For A Secret File

Some time over a decade ago, the arrival of inexpensive PCB fabrication revolutionised the creation of custom electronics on a budget. It’s now normal for even the smallest projects we featur…

Magnetic Power Cable Makes Mobility Scooter Much Better

Sometimes, you have to wonder what major manufacturers of assistive tech are thinking when they design their products. [Niklas Frost]’s father has MS and uses an electric mobility scooter to …

Unusual Port Combines DisplayPort And HDMI

Everyone knows you can’t plug an HDMI cable into a DisplayPort… port, and yet a recent video from [Jon Bringus] challenges that seemingly obvious assumption. The hardware in question is…

That’s A Lot Of Building Systems

The only thing makers like more than building things is making systems to build things. [Eric Hunting] has compiled a list of these modular building systems. You’ve certainly heard of LEGO, g…

What’s A Transfluxor?

In the 1967 movie The Graduate, a wise older man gives some advice to the title character: plastics. Indeed, plastics would become big business. In 1962, though, a computer-savvy character might ha…

Washing Machine Motors Unlocked

There’s great potential in salvaging a motor from a broken appliance, but so often the part in question is very specific to its application, presenting a puzzle of wires to the experimenter. …

The Photodiode You Never Knew You Had

Optoelectronics hold a range of possibilities for the hardware experimenter — indeed who among us hasn’t added LEDs aplenty to our work? What many of us may be unaware of though is that…

Op-Amp Drag Race Turns Out Poorly For 741

When it was first introduced in 1968, Fairchild’s 741 op-amp made quite a splash. And with good reason; it packed a bunch of components into a compact package, and the applications for it wer…

A Classroom-Ready Potentiometer From Pencil And 3D Prints

If you need a potentiometer for a project, chances are pretty good that you’re not going to pick up a pencil and draw one. Then again, if you’re teaching someone how a variable resistor…

Ring Around The Inverter

[Dr. Shane] asks the question: what happens if you connect the output of an inverter logic gate back to the input? In theory, it doesn’t make sense, but depending on the gate’s physical…