Tag: digital

Betwixt the Realms

For all of the many times I have done it, I have never gotten tired of typing a command, or clicking a button on a screen, and watching something happen in the real world.

GenPIC Processor
The microprocessor on a GenPIC PCB assembly

An LED turning on, the click of a relay, or even a motor beginning to spin… These represent a moment when the seemingly ethereal digital realm of our computers interact with the physical domain.

I have spent my entire career dealing in the interface between the ethereal and the physical, working where the two meet. Turning sensor readings into digital, and then turning the digital into actions in the everyday world. I played with this interface as a teenager, learning the basics. My wisely chosen college degree was tailored to this task, an electrical engineering degree with a heavy dose of computer science. Professionally I have dealt with microcontrollers, high performance analog to digital systems, and programmable logic controllers, all straddling the boundary line from digital to physical.

Continue reading “Betwixt the Realms”

An Old Project

I have been messing about with electronic circuitry for almost four decades. I recently came across an early example of my work. The device is a digital event counter built around classic 74xx series logic. A chain of 74190 decade counters feed a set of 7447 decoder drivers and seven segment LED displays. A plastic project case with switches and connectors reminds me I have been building little devices for a very long time.

A Digital Event Counter
A digital event counter built when I was fifteen years old.
In some ways the unit is very similar to one of my more recent builds. Perfboard and point-to-point wiring are still standard construction techniques. The technology may have changed across the years, becoming far more complex, but some parts have remained the same.

Continue reading “An Old Project”