Which Pi is Right for Your Project?

4 min read Michael Carroll on Mar 7, 2018

You’re likely familiar with the Raspberry Pi, a single-board computer available for $35… Or was it $5… Or $10? You’d be correct in each case—since its introduction as a single board in 2012, the Pi family has multiplied into several offerings. These include the Raspberry Pi 3, Pi Zero, Pi Zero W (and Zero WH), and the Pi A+, each with different capabilities and price points.

In addition, the older Pi 1 and Pi 2 are available, as well as a stripped-down version of the Pi3 in the form of the Compute Module, meant for industrial applications.

So which version is right for you? Read on to find out!

Raspberry Pi 3

Raspberry-Pi-3The Pi 3 is the current flagship of the Pi Family, and features a full-sized HDMI port, along with four USB A ports and an Ethernet jack. It even has a 3.5mm audio jack that can also be used to produce analog video signals if needed, and a connector to allow you to capture images with its official camera. The Pi3 features a quad-core 1.2 GHz 64-bit processor, exhibiting a performance of around 10x that of the original Raspberry Pi.

What this means in practical terms is that if you want to do processor-heavy tasks like heavy game emulation or working with cryptocurrency, the Pi 3 is the right choice.

In addition to processing capabilities, its port selection rivals that of modern notebook computers, meaning that you won’t have to spend money on a USB hub or physical Ethernet connection if needed. Additionally, it includes pre-soldered GPIO headers, so if you need to attach a ribbon cable or other accessories, you just plug them in.

Raspberry Pi Zero/Zero W/Zero WH

Raspberry-Pi-Zero-OverheadIf you were to strip nearly everything unnecessary off of the Raspberry P3, reduce component sizes as much as possible, and only need a less powerful single-core processor, you’d get the Raspberry Pi Zero.

Why, you might ask, would you want something like this?

First of all, if cost is a factor, the Pi Zero is only $5, making it nearly disposable if your application calls for it. Secondly, the size, at 1.18 x 2.55 inches and a thickness of less than a quarter of an inch, lets it fit into places that the (still quite small, as it roughly fits on a credit card) Pi 3 couldn’t come close to fitting into. In fact, it’s so small that hackers have shoehorned them into video game cartridges, fitting an entire emulator setup into what was once a single game.

The tradeoffs can be inconvenient, however. If you want built-in Wi-Fi connectivity, you’ll need to upgrade to a Pi Zero W, bringing your cost up to $10. If you need headers, you’ll either have to buy them separately and break out the soldering iron, or go for the “WH” version that sells for $14. Add on a USB hub (since it only has one micro-USB port) and a fairly uncommon mini-HDMI cable that you’ll likely need, and the cost (and space) savings of going with the Zero are greatly reduced. On the other hand, even at a similar cost, its small form-factor can make it a very interesting option.

Raspberry Pi 1/2, A+, Compute Module

Pi2ModB1GBThe Pi 3 and Pi Zero(s) deservedly get the most attention today, but it’s worth noting that you can still buy the original Pi and Pi 2. It’s tough, though, to see the justification unless you specifically need those same specs for a certain type of equipment or scientific experiment.

The A+, however, could be a useful form factor in some applications, as it features soldered headers and a different port configuration and a size (2.56 x 2.20 x .47 inches) that sits between the Pi Zero and a full-sized Pi 3. Still, at around $20, and with lesser processing specs than the Pi Zero and no built-in Wi-Fi, appropriate applications are limited.

Another interesting form factor is the Compute Module, which has the same BCM2837 processor as the Pi 3, along with 1GB of RAM, but is integrated into a board that fits into a DDR2 SODIMM connector normally used with laptop memory. It also features 4GB of built-in flash memory instead of a micro-SD card slot. Meant as a flexible module for industrial applications, its companion IO dev board allows access to 120 GPIO pins. While you may wish to stick with the Pi 3 or Zero W, it’s good to have other options available in case your needs change, or you’d like to scale your design to something used by hundreds or thousands of customers.

Regardless of which device works for your application, it’s worth contemplating that even the original Pi with its 700 MHz processor would have been considered a very capable computer just a little over a decade before it was released. At $35 or less, the Raspberry Pi family has certainly been successful in its original mission to enable computer science education.

This is a guest post from Jeremy S. Cook and Zach Wendt, engineers who enjoy sharing how electronic components can best be applied in projects. Jeremy writes for a variety of technical publications. Zach works for Arrow Electronics, a major supplier of Raspberry Pi products.