Building a toaster oven temperature profile controller might not sound so exciting, but that's just the first layer of the onion! The exact same hardware and software can be used to build all sorts of embedded microcontroller projects, and you can do so without ever installing a software development environment anywhere because it's all inside the microcontroller itself. This is all based on relatively new technology called "WebUSB" and "Web Serial."
In 1970, Signetics engineer Hans Camenzind designed the 555 programmable timer chip. Fifty-three years later, it’s still going strong as the world’s largest selling integrated circuit. I’ll explain the inner workings of the 555 and help make you an expert on creating your own 555-based designs.
The most often used trouble indicator in a circuit is the ubiquitous LED. Unfortunately, we don’t always have eyes on our equipment to see when problems arise. Here’s a simple way to add an audio trouble alarm to circuits that only have a visual indicator.
This article describes the process of designing and building a custom Raspberry Pi HAT circuit board. This HAT works with a Python script to record and live plot battery voltage, temperature, and capacity. The ability to log data over an extended period is an included useful feature.
This project started out as a challenge to myself: Could I cram a full-featured Z80 microcomputer using DIP packages onto an ExpressPCB MiniBoard (3.8” by 2.5”)? Here’s what happened.
Twenty years ago, I published an article in Nuts & Volts about designing a general-purpose programming system: the LP120. I’ve used the LP120 heavily for the last 20 years to support my eight-bit design hobby. It now has uploadable drivers and programming modules for many eight-bit micros, EPROMs, and GALs. However, things have changed since 2000. Back then, few microcontrollers had more than 4K bytes of program memory. Now, eight-bit PICs have up to 64K words of memory. Clearly an update to the LP120 was called for.
The last time I had my hearing aids serviced, I discovered that the devices included a T-mode operational feature. The T-mode (or Telecoil) setting allows you to receive audio signals fed to an induction loop, which is just a wire loop laid on the floor around the perimeter of the desired area. Induction loops can be found in places such as concert halls, movie theaters, auditoriums, churches, banks, and public buildings where PA announcements are common. I decided to build an installation for my home. Here’s how it went.
