Microcontrollers

An ESP32 / Teensy 3.5 Super Clock

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.

Libraries and Headers in C: A Tutorial

If you’ve written a program for a microcontroller board such as the Arduino, Raspberry Pi, or Propeller QuickStart, you have relied on software libraries that provide constants and functions.  Often, we use software libraries without thinking much about them.

When you start to write libraries, it takes time to read documents, follow directions, and experiment with simple functions. Fortunately, after you understand how to create libraries and header files for the software tools you use, you'll have a useful skill that can simplify programming tasks.

Even if you never create a library, you probably want to know how they work and what they contain. This tutorial provides information that gives you a good start.

Build the Laser Pencil Engraver

Several months ago, an idea popped into my head for a fun project. I wondered if I could burn some characters into the yellow paint of a No. 2 pencil with one of those powerful diode lasers available on eBay. Perhaps it could be my name or my grandkid’s names, or even a happy birthday message to my lovely wife. Here’s how I did it.

Build an Internet Digital Clock

The advent of the ESP32 Wi-Fi development boards allows for an increase in the sophistication of a digital clock. It doesn’t take much imagination to envision a digital clock with a large LCD display to not only show the usual time, date, temperature, and humidity, but to also be able to retrieve things from the Internet like the weather or weather forecast, and stock market reports as well. This seven inch clock also automatically corrects for Daylight Savings Time.