What could be more fun than building a miniature oscilloscope? Not one with an LCD screen, but a scope with a real live cathode ray tube just one inch in diameter. All the parts -- including two 6AU6 vacuum tubes -- will be housed in a 5” x 7” x 2” box.
The last few years have seen a massive resurgence in the popularity and availability of voltage-controlled synthesizers. The very simple ribbon controller we’ll construct in this article will be used to control any of the myriad voltage-controlled modulation opportunities provided by the typical voltage-controlled synth.
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.
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.