It used to be a rite of passage to be able to do the math necessary to design various bipolar transistor amplifier configurations. This doesn’t come up as often as it used to, but it is still a good skill to have, and [Void Electronics] walks us through a common emitter amplifier in a recent […]
Variable capacitors may be useful, but the air gap that provides their capacitance is their greatest weakness. Rather than deal with the poor dielectric properties of air, some high-end variable capacitors replace it with a vacuum, which presents some obvious mechanical difficulties, but does give the resulting capacitor a remarkable quality factor, high-voltage performance, and […]
At the risk of starting a controversy: is there anyone who goes to the effort of setting up Home Assistant who wouldn’t really rather be living on the Enterprise-D? If such a person exists, it’s not [steve-gibbs5], who has not only put together a convincing LCARS dashboard on an Android tablet, but has also put […]
EDM (Electrical Discharge Machining) is one of those specialised manufacturing processes that are traditionally expensive and therefore somewhat underrepresented in the DIY and hacker scenes. It’s with great delight that we present EnderSpark, a solution to not one but two problems. The first problem is how to perform CNC operations on hard-to-machine materials such as […]
At some point during our primary school careers, most of us probably constructed a simple compass, often by floating a magnetized needle on a cork in a cup of water. The water in such a configuration not only lets the needle spin without friction, but also dampens out (so to speak) the needle’s tendency to […]
Continuing his reverse-engineering of the Intel 8087, [Ken Shirriff] covers the conditional tests that are implemented in the microcode of this floating point processing unit (FPU). This microcode contains the details on how to perform the many types of specialized instructions, like cos and arctan, all of which decode into many microcode ops. These micro […]
[Ronan] likes 35mm film photography, but the world, of course, has gone digital. He picked up an Epson FilmScan 200 for about €10. This wonder device from 1997 promised to convert 35mm film to digital at 1200 DPI resolution. But there was a catch: it connects via SCSI. Worse, the drivers were forever locked to […]
Emulating older computers on microcontrollers has been a staple of retrocomputing for many years now, with most 8-bit and some 16-bit machines available on Atmel, ARM, or ESP32 platforms. But there’s always been a horsepower limit, a point beyond which a microcontroller is no longer enough, and a “proper” computer is needed. One of those […]
The Tamagotchi Connection is a series of Tamagotchi toys that took the original portable pet concept and mixed things up with a wireless connection, which allowed you to interact with the pets of other proud Tamagotchi owners. This wireless connection is implemented using an infrared transceiver, somewhat like IrDA, but as [Zach Resmer] discovered while […]
While EEG research might help you figure out extrasensory perception, we won’t be betting on it. However, if you want to read EEG data and use an ESP32, [Cerelog-ESP-EEG] might be the right project for you. The commercial project is an 8-channel biosensing board suitable for EEG, EMG, ECG, and brain-computer interface studies. However, the […]