When the Raspberry Pi Foundation initially released their system-on-a-chip (SoC) in February 2012, the goal was to provide a low-cost educational platform for teaching kids to program hardware with languages like Scratch or Python. But the power of a desktop computer packed into a form factor the size of a credit card was just too good to pass up by the DIY maker community. The Raspberry Pi was an unexpected instant success. As founder Eben Upton wrote on his blog:

“At the time, we thought our lifetime volumes might amount to ten thousand units – if we were lucky. There was was no expectation that adults would use Raspberry Pi, no expectation of commercial success, and certainly no expectation that four years later we would be manufacturing tens of thousands of units a day in the UK, and exporting Raspberry Pi all over the world.”
— Eben Upton celebrating the 10 millionth unit sold in September, 2016.

The Raspberry Pi is great for electronics projects that require more processing power than a microcontroller (like Arduino) can provide — from home HTPC media streaming (like a DIY alternative to Chromecast) to building your own robot, there’s a lot you can accomplish with a pocket-sized computer running Linux. In this article, we’ll take a closer look at the Raspberry Pi, what it is, and the skills you’ll need to acquire or hire to bring your DIY electronics project to life.

What exactly is a Raspberry Pi?

So by now, you probably already get that it’s a portable computer on a board, but what made it such a hit among everyone from high school students to professional engineers? For that we’ll need to take a closer look under the hood. For $25, your basic Raspberry Pi Model B+ ships equipped with:

  • ARM CPU/GPU: The Pi’s brain is a Broadcom BCM2835 SoC which includes an ARM1176JZFS running at 700Mhz, and a Videocore 4 GPU for graphics.
  • 512MB RAM: This may not look like much compared to the 4-8 GB RAM of basic home computers today, but it’s a great deal more RAM than the paltry 32-128 MB the average PC was sporting in the late 90s.
  • SD Card Slot: The Pi boots up through its own flavor of the Linux OS called Raspbian installed on an SD Card. The SD card itself is typically sold separately, and can also be loaded with your OS of choice.
  • HDMI Port: The same HDMI you use to hook up your laptop to your high-def TV can be used to provide a display for your Pi.
  • RCA Socket: Don’t have a high def TV? No problem, just use the old fashioned RCA composite video cable to hook up to your analog TV.
  • USB Port: The Model B+ ships with four USB ports. Hook up a mouse, keyboard, and monitor (via HDMI) and you’ve got yourself a “desktop” computer.
  • Ethernet Port: Connect to the internet like any standard desktop computer.
  • Micro USB: The Pi can be powered via a 5v Micro USB connection.
  • Audio Jack: Standard 3.5mm headphone jack for audio, simply plug-in your favorite headphones or speakers and you’ll have sound.
  • GPIO Pins: The Model B+ sports 40 GPIO (general purpose input/output) pins for interfacing with the real world. Connector sensors, microcontrollers, or other devices as needed to bring your project to life.

Altogether the basic Model B has power roughly equivalent to a Pentium II Processor or a computer from the late 90’s, but with better quality graphics — not bad for $25.

Meet the Models

The Raspberry Pi has evolved with several iterations across 3 generations since its initial release in 2012. Let’s take a closer look at what’s available in the Raspberry Pi catalog:

Raspberry Pi 1 Model B+
As we covered above, the Model B+ is the successor to the original Raspberry Pi Model B. It replaced the old Model B in July 2014 adding two more USB ports, 14 more GPIO pins, improved audio, lower power consumption, and other improvements.

Raspberry Pi 1 Model A+
The original Model A was released shortly after the Model B in 2012 as a simpler cheaper alternative. It was superseded by the Model A+ in November 2014. The board is a stripped down version of the Model B+, with only one USB port and no ethernet jack.

Raspberry Pi 2 Model B
Released in February 2015, the Pi 2 Model B is a nice upgrade from the first generation, replacing the CPU with a 900MHz quad-core ARM Cortex-A7 and boosting memory to 1GB RAM. Like the Model B+ it still has 4 USB ports, 40 GPIO pins, HDMI, Ethernet port, and audio jack.

Raspberry Pi 3 Model B
Released in February 2016, the Pi 3 Model B expands upon the Pi 2 Model B by upgrading the CPU to a 1200 MHz quad-core ARM Cortex-A53. It also added built in 802.11n Wifi and Bluetooth 4.1 support, which was previously only available as a separate addon. The Pi 3’s 64-bit processor is a huge performance improvement over its predecessors. While it uses the same VideoCore IV GPU as previous generations, it is clocked higher at 400 MHz (compared to Pi 2’s 250 MHz), allowing it to handle 1080p video playback at 60fps.

Raspberry Pi Zero/Zero W
Released in November 2015, the Foundation toutes the Pi Zero as being “half the size of a Model A+, with twice the utility.” With a 1GHz single core ARM11 processor, it’s actually faster than the Pi 1, and can give the Pi 2 a run for its money in speed tests that don’t involve parallel processing (it only has one core after all). Best of all, you get all of that on a tiny board for only $5. Just add Bluetooth and Wifi from the Pi 3, and you have the Zero W which released in February 2017 for $10.

Compute Modules
In addition to their standard line of boards, the Compute Module line was established on April 7, 2014 for industrial applications. The initial Compute Module took all the internals of a Pi 1 Model B+ and fit them onto a 67.6x30mm form factor that fits into a standard DDR2 SODIMM connector (the same type of connector used to fit RAM into your laptop). It also sports 4GB of eMMC Flash onboard memory to replace the SD card in the Pi. Today, the Compute Module 3 packs the power of a Pi 3 Model B (BCM2837 SoC and 1GB RAM) into the same form factor.

Using the Raspberry Pi for IoT, Education, and Beyond

Now that you’ve learned about the Raspberry Pi, you should be ready to put theory into practice and take on a tutorial project of your own. Whether it’s building a robot, an educational tool, or as an IoT hub for turning your house into a smart home, your imagination’s the limit when it comes to what you can accomplish with the Raspberry Pi.

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