Having read about the ESP8266 NTP clock in previous issues of Nuts & Volts, an idea came to mind to construct an interface camera using the ESP8266. In this project, we used an old Android phone as a camera source and linked to an ESP8266 based webserver. The phone acts as a camera server and the ESP8266 web server acts as a client to the camera server. The webserver displays the live webcam on its web page.
Here are a few of the many possible variations on the general theme of discrete-logic digital clocks. If you have a few LED displays, counters, drivers, and simple logic, you can probably build a clock. Consult the datasheets of the ICs you choose to use, breadboard everything first, and have fun.
When the concept of electromagnetic waves was first proposed around 1864, it was met with great skepticism. As a result, the idea languished for a long time. It took several decades for a handful of dedicated persons — infatuated with the mysteries of electricity and magnetism — to finally put the theory on a solid footing.
In this article, we’ll take a look back at this period that launched the serious study of radio waves. We’ll examine the contribution of James Clerk Maxwell, the man most responsible for the concept. Next, we’ll look at the work of several notable scientists who came after Maxwell, and see how they confirmed the existence of radio waves.
The February and March 2018 editions of Nuts & Volts featured my article detailing the Arduino Graphics Interface (AGI) project which described a general-purpose hardware and software platform that could draw graphical objects onto the face of any analog oscilloscope. A reader challenged me to see if the AGI concept and software library could be ported to the newer and faster TEENSY 3.6 processor. This article describes the new and improved TEENSY Graphics Interface project that implements a fully operational “CRT Clock” as a working demonstration of a TEENSY based graphics platform.
This November, in Versailles, France, representatives from 57 countries are expected to make history. They will vote to dramatically transform the international system that underpins global science and trade. This single action will finally realize scientists’ 150 year dream of a measurement system based entirely on fundamental properties of nature. The International System of Units — informally known as the metric system — will change in a way that is more profound than anything since its establishment following the French Revolution.
Sometimes I wonder which of my portable digital voltmeters I can trust — the B&K, Fluke, or Amprobe. Usually, they’re pretty close but it bugs me not knowing whether they are right on the nose. Fortunately, these days, there are a number of very accurate voltage reference circuits that you can build or purchase for a few dollars.
Phased arrays have been used for years in military radars for long range detection of missiles. They’re also widely used in military and commercial aircraft radars and some satellites. These phased arrays are expensive, but today thanks to new technology and higher frequencies, phased arrays are smaller and more affordable making them practical for new wireless devices. This article is an introductory tutorial on this special antenna type you need to know about.
Filters are one of the most important and widely-used circuits in all of radio at any frequency. Understanding how they are specified and used will make you a better electronics designer, whether you build your own or simply buy them from a vendor.
Electronics as a hobby is unique in that it touches upon just about every other technology or area of potential interest, from photography to cycling. Don’t feel you need to stick with pure electronics. Get out of your comfort zone and explore some of the many related technologies.
A casual observer might think that wireless systems consist primarily of filters connected by the occasional bit of circuit. Block diagrams of transceivers often include as many filters as any other function. This is true at the system level, just as it is at the circuit level — and many circuits behave in a filter-like way, whether intended to be a filter or not! That makes understanding filter basics important for wireless success.