Everything for Electronics
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Adding an Audible Circuit Alarm

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.

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Build a General-Purpose Raspberry Pi Data Logger Hat

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.

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Take the Z80 Challenge

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.

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Updating a General-purpose Programming System

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.

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Build an Audio Loop System

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.

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Build a Digital Light Saber

Want to “paint with light?” This article explains in detail how you can build a low cost (<$100) microprocessor-controlled LED light saber that provides as much or more capabilities than professional light wands.

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Harvesting Electricity From The Environment

With "smart" cell phones, Wi-Fi, RFID tag systems, and so many other new applications for radio waves these days, it is obvious that we are immersed in an electromagnetic field ("EMF") just about everywhere we go. Here's a circuit to experiment with collecting and measuring the energy present in our environment.

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