After creating an Internet connected digital clock using the Adafruit RA8875 driving an seven inch LCD display, I decided to step it up a notch and add several additional features including: the ability to set an alarm; a countdown timer for uses like monitoring an exercise program; a weather display to provide brief conditions at 10 different cities; a real time stock market report that gives the changing prices for a selection of stocks; and lastly (just for fun), a Mandelbrot fractal generator to produce those wonderful images.
By now, you’ve certainly heard of the forthcoming fifth generation (5G) wireless technology. There’s a tremendous amount of hype about 5G as the various cellular operators try to pre-sell you on the new benefits and services. Commercial 5G services won’t go online until later this year, but we should see plenty of 5G action in 2020. For that reason, you’ll need to know more about 5G to understand what impact it will make on you and the world in general. Here’s a status report to bring you up to speed.
It was 1923, and radio was the phenomenon of the day. Over 600 broadcast stations were on the air, and Americans bought 100,000 receivers that year. (Sales would jump to 1,500,000 in 1924.) Many owners hosted “radio parties” and danced to the latest jazz music with their friends. At the same time, the game of Bridge was sweeping the country. Read how one card company used this “new technology” to promote their products.
The whole Internet of Things (IoT) phenomenon has been around for a while now. But have you tried to create an IoT device on your own? If so, you know it’s not easy. However, it is now easier than ever as many of the manufacturers of IoT wireless chips and modules are providing the hardware and software to make an IoT device happen with minimum work. One example is the Wireless Xpress BGX13P module starter kit from Silicon Laboratories.
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.
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.
Most frequency counters can tolerate only low levels of RF at their input, but here’s a way to safely measure the frequency of an RF signal of up to 200 watts with your existing frequency counter.