This month I am writing my column on "Pi Day." Pi Day is an annual event that celebrates the number Pi, an irrational number that is approximated to two decimal places as 3.14 and thus celebrated in the United States on March 14. Pi, of course, is an important number in geometry and trigonometry because the circumference of a circle is 2πr (2 times Pi times r) where r is the radius of the circle and Pi is represented by the Greek letter π. The area of a circle is also calculated using Pi in the formula area=πr2 (Pi times r squared). In mathematics, a rational number can be represented as a fraction, one number divided by another number. An irrational number like Pi cannot be represented as a fraction, and the digits to the right of the decimal point go on forever in a never-repeating sequence.
Pi day has also become a time when the technology community celebrates all things Raspberry Pi. You may remember from previous columns that the Raspberry Pi is a low-cost ($35) computer designed to help students learn more about computers. This year, the Raspberry Pi celebrates its fifth anniversary since its first release in February 2012.
It seems that each year the Raspberry Pi foundation brings out something new. This year, the new toy is the Raspberry Pi Zero W. This is a Raspberry Pi Zero (released last year) with the addition of built-in wireless networking (Wi-Fi) and Bluetooth. The board is designed to sell for $10, which is $5 more than last year's Pi Zero. Both of the Zero models use an ARM 11 single core processor with a Broadcom VideoCore IV graphics processing unit (GPU) and 512 megabytes of RAM. The Zeros are about the size of a pack of gum and typically run a Linux operating system.
The current flagship of the Raspberry Pi line is the Pi 3. This $35 computer is about the size of a deck of cards and packs a quad core 64 bit ARM 7 processor with 1 gigabyte of RAM, the VideoCore GPU, and built-in wireless and Bluetooth.
In addition to the Raspberry Pi, the Raspberry Pi foundation has designed some standard add-ons for the computers. The sales of these add-ons help to support the nonprofit Raspberry Pi Foundation as it continually develops educational resources and enhances the Pi to reflect the ever-changing state of technology. The Pi Camera is a camera developed specifically for the Pi and attaches to a special high speed bus allowing photos to be quickly moved from the camera's sensor to the Pi's memory. The Pi camera supports 8-megapixel resolution images and full HD video at 30 frames per second. It is available for $25 for both the Pi 3 and the Zero. The Pi case is for the Pi (there is a case for the Pi 3 and a smaller one for the Pi Zero), which allows easy access to plug accessories like the camera into the Pi. There is also a standard 7-inch touch display and a case that holds both the Pi and the display.
Other companies have joined into the mix as well. Western Digital makes the Pi Drive. This is a 3.14-gigabyte hard drive that plugs into a USB port on the Pi. Several companies make add-ons called HATS (hardware attached on top). These can add new features to the Pi like small video screens, music amplifiers, and controllers used for robotics. Adafruit and SparkFun are two companies that offer a variety of these HATS.
You may wonder how these little computers are being used. Clearly, the Pi is a good choice for someone that wants to learn about computers and programming. The standard Raspbian software provided by the Raspberry Pi Foundation includes a learning environment to comprehend the Python language and also supports the C, C++, and Java languages out of the box. It is easy to add support for Ruby, PHP5, and almost any other programming language. The Raspberry Pi is also a popular choice for creating a media center. Various versions of the Kodi media center platform are available for the PI. Another popular use is to create a retro gaming platform. Retrocade Pi and RetroPie provide game emulators for many of the old game platforms including arcade machines and platforms like the Gameboy, Commodore 64, and old Atari systems.
The Raspberry Pi has become a very popular platform to include as a part of new things that people create. Some people have fashioned miniature arcade game consoles with a Pi inside to run the games. Others have used the Pi to run 3D printers or various robots. The Pi has been used in weather stations, wildlife cameras, security cameras, and photo booths. The Raspberry Pi has become one of the most popular tools to build your own Internet of Things, thing. You can use it to create your own Amazon Alexa device, browse the web, or to write newspaper articles. Happy Pi Day!