The popularity of repairing and restoring tube radios has highlighted the need for a variety of test instruments. After repair or restoration of a radio, the final step is often alignment. For an AM radio, a signal generator and voltmeter will do a good job. But with an FM radio, using a signal generator and voltmeter does not always produce the best results. So, I came up with my own design using a digital signal generator module, Arduino processor, and digital display.
For our “Designing With Microcontrollers” class at Cornell University, we built a pinball machine with electronic components controlled by software on a PIC32 microcontroller. This article details the design process, challenges we experienced, and solutions we came up with while completing the project from start to finish.
I’m a digital clock nut. I began experimenting with the newer Nextion displays, which I really like. I’ve produced digital clock versions for the 3.5, 5, and 7 inch size Nextion display. They all run from the same printed circuit board and have several different functions.
When I was in university, a local restaurant owner approached me about designing a marquee lighting system in his entrance stairwell. He wanted to attract and guide more customers to his business. He never did agree to the proposed price, but it planted a seed. Since that time, I have seen many marquee-based systems at places like local theaters or animated holiday displays. So, I set out to design my own system.
This article describes a Hall-effect based magnetometer that uses an inexpensive analog Hall-effect sensor, an Arduino, and LCD. The linearity of the magnetometer is surprisingly good when compared against a commercial magnetometer. This unit can be operated manually or make measurements under computer control, so we’ll use our magnetometer in a computer-controlled setup to measure the BH-curve of small sample of magnetic material.
Could I get by with fewer amenities and shrink the size, weight, and power requirements of my keyer to make it more portable when going on a mini-DXpedition? It was worth an investigation.
In the 1950s and ‘60s, Popular Electronics and other magazines carried ads for strange looking machines called Geniacs and Brainiacs. The ads claimed they were “electric brains” that could play Tic-Tac-Toe and NIM. A while ago, I bought several sets on eBay and I would like to share my experiences of learning about them and my sometimes frustrating — but successful — efforts to get them to work.
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.
In about 10 minutes and for about $6, you can display the blood flow through your finger. From this measurement, you can extract your heart rate, check for arrhythmia, and even modulate a red light to pulsate with your heart rate. Here’s how.