Last year, a friend of mine told me about the Arduino. He was using one with his model railroad. Hang on, I said, you don’t know anything about computers. “I don’t need to”, he replied. “It only took me a few weeks to learn how to use the Arduino.” My friend is a business executive. The Arduino went on my Christmas wish list (thanks Bob) and I have not looked back.

The Arduino is an open-source computer system. At its heart, it is a programmable micro-controller (specialized computer). But at the core, Arduino is a standardized platform for:

• controlling devices, such as motors;
• connecting to peripherals, such as expansion boards and displays; and
• reading inputs, such as switches and sensors.

When you look at the picture of the Arduino UNO, you will see many pins for analog and digital input and output. The Arduino is easily programmed through a USB connection to your computer. It’s all open-source and supported by an ecosystem of millions of users.

Micro-controllers (MCU) have been around since the early 1970’s. Traditionally, they have been proprietary, the domain of specialists. They have been difficult to program. Arduino arrived on the scene some 30 years after the introduction of MCU. It made the micro-controller readily available and usable by a very large audience. This breakthrough contains at least three innovations:

• Easy to program. The Arduino IDE (integrated development environment) adopted the widely-known “C” language. This replaces low level assembly language. The IDE connects easily to the Arduino using a USB cable. It comes with a wide range of software libraries for common functions. And, it’s free.
• Easy to interface. This is true in several ways. First, the Arduino circuit board contains a large number of digital and analog inputs and outputs which are already interfaced with the MCU. Second, the Arduino circuit board is standardized to enable easy attachment of peripheral controllers or “shields”. Third, it is easy to interface to your own circuits, on breadboards, using jumpers.
• Open-source. Everything about the Arduino ecosystem is open-source. This means that anyone can add to the ecosystem with complimentary products, modifications and knowledge. There is also a wide range of compatible products and clones, some at very low cost. The culture in the user community seems to be to purchase at least one genuine or licensed board to support the ecosystem. (Prices vary dramatically. As of today, genuine Arduino UNO boards sell for around $30; clones cost around $6.)

What to do with an Arduino

All well and good. So, what can you do with an Arduino? Here are some far-out ideas from Element14 and Instructables. More mainstream uses for Arduino are home automation and Internet of Things (IOT). The following are three projects I have done with the Arduino.

• Remote Sensing. My first project with the Arduino was to create a remote sensor, in this case a thermometer. A thermistor (temperature sensitive resistor) was connected to my Arduino. Then, the cheap ESP8266 WIFI module. Total cost, around $10 in parts. The ESP8266 is a complete Internet system on chip with a strong WIFI link. It can also serve as a web server. When I was finished, my digital thermometer had its own web page that I could monitor from anywhere on the net.
• Signal Generator. This is a piece of test equipment that usually costs $250 and up. However, a little AD9850 module imported from China connects to the Arduino. Together, they provide a complete and sophisticated direct digital synthesizer. You can source this module for around $12. In my proof of concept breadboard, I built an Arduino-controlled signal generator covering 0-40 MHz. It puts out around 1 volt of excellent quality RF. I am currently building this signal generator into a little box (3D printed, of course) containing an LCD Touch Screen ($8) for control. What fun!
• 3D Printer. When the control board on my 3D printer died, I substituted the Arduino as the new controller. By combining an Arduino Mega with a RAMPS 1.4 board, you have a complete 3D printer controller for under $25. You just connect the wiring from your printer and install some open-source firmware.

If you are into or want to get into “making”, the Arduino in its many flavors provides a powerful platform to prototype and then build all kinds of solutions. It’s great for kids of all ages, including chartered accountants and retired management consultants.