Raspberry Pi Board Guide: Zero vs Models A and B

You are interested in buying a Raspberry Pi, but once you start looking, you run into a problem: why are there so many models?

While all the different Raspberry Pis can do many of the same jobs there are specific tasks that are more suitable for specific boards. For example, the Raspberry Pi Zero has a lower form factor than others, so it is often used in projects with limited space.

Here’s what you need to know about each Raspberry Pi model, and what project they’re best suited for.

3 flavors of pi

As you probably know, there are several major Raspberry Pi models available. At the time of writing, eight raspberry pis can be purchased, but they fall into three types.

raspberry pi board guide

Model A: First released in 2013, the second iteration (A+) arrived in 2014.

Model B: Having appeared with the very first Raspberry Pi in April 2012, the «+» model appeared in July 2014. A few months later, the Raspberry Pi 2 was launched in February 2015. It was succeeded by v1.2 Raspberry Pi 2 in October 2016. The Raspberry Pi 3, meanwhile, arrived in February 2016.

Each of these Raspberry Squeaks uses a B board, as opposed to the smaller A board.

Zero: Finally, there’s the Raspberry Pi Zero board, a scaled-down version of an already tiny computer. It was first launched in November 2015 for just $5 and was replaced by the 1.3 board in May 2016. A third board, Zero W, hit store shelves in February 2017, while Zero WH was introduced in early 2018.

Although they may seem very similar, these boards only have a few identical components. For example, they all use the same graphics: Broadcom VideoCore IV, OpenGL ES 2.0, MPEG-2 and VC-1 (with license) and HDMI support with a high performance 1080p30 H.264/MPEG-4 AVC decoder and encoder.

While three Raspberry Pi «flavors» are offered, only a few are currently available. Read on to find out more, their features and their best uses. When you’re ready to buy, check out our guide to to learn more about the Raspberry Pi!

Raspberry Pi 1 Model A+

The A+ model measures 65mm × 56.5mm × 10mm and weighs 23 grams. It is a revision of the discontinued Model A. Smaller than its predecessor, it uses the ARMv6Z (32-bit) architecture with Broadcom BCM2835 System-on-a. -Chip (SoC). This includes a 700MHz single-core ARM1176JZF-S processor, 512MB of RAM, and the same graphics found on every Pi model to date.

raspberry pi board guide

The device has one USB port and a 15-pin MIPI camera serial interface connector. This can be used with the Raspberry Pi camera module and its NoIR variant. A MIPI display interface is provided for LCD panels, while a 3.5mm TRRS connector is provided for composite video and audio output. A standard HDMI output is also on the board. Unlike the original Model A, the A+ has a microSD card slot.

There is also a 40-pin array — 28 of them for GPIO, and the rest for I2C, UART and SPI. They are designed to connect various types of equipment.

Best use: Model A+ limitations make this Raspberry Pi especially suitable as a security camera with motion detection. Consider this also for a robot brain, a NAS controller, or even the center of a high altitude balloon.

Raspberry Pi 1 Model B+

Using the same architecture and SoC as the A+, the Raspberry Pi Model B+ features a larger size of 85.6mm×56.5mm, providing space for additional connections. This increases the weight to 45 grams.

raspberry pi board guide

Four USB ports are provided. This is via the built-in five-port USB hub — the fifth port is dedicated to the Ethernet (10/100 Mbps) port. Like the A+ model, a 15-pin MIPI Camera Interface (CSI) connector is installed, as well as a MIPI Display Interface (DSI) for raw LCD panels (different LCDs can be bought for Raspberry Pi computers).

This is the first version of the Pi to offer a microSDHC slot for high-speed microSD cards.

Best use: you can start a low level server with B+. For example, a wireless print server or a network monitoring tool.

Raspberry Pi 2 Model B

Echoing the B+ form factor, the Raspberry Pi 2 has the same dimensions and weight (85.6mm × 56.5mm, 45 grams). This time, however, the hardware has been increased.

Now built on ARMv8-A (64/32-bit) architecture, the Pi 2 features a Broadcom BCM2837 SoC, a quad-core ARM Cortex-A53 64-bit 900MHz processor, and a comparatively large 1GB of RAM. Other than that, there are no differences with the B+, but the faster CPU and RAM boost provides a significant performance boost.

Best use: my own Pi 2 has been used for several projects such as an inspirational digital photo frame It was even used to install and run doom no emulation. This is a versatile device that can even be used as a desktop computer.

Raspberry Pi 3 Model B

Accelerating the Model B specs, the Raspberry Pi 3 — with the same weight and dimensions — features a 1.2GHz 64-bit quad-core ARM Cortex-A53 processor (as opposed to the 900MHz Pi 2 chip).

raspberry pi board guide

Powerful USB resource boost is also included. No longer limited to USB Bluetooth and Wi-Fi dongles, the Pi 3 has 802.11n wireless and Bluetooth 4.1 on board. This means that the power of these devices is properly regulated (some dongles were unreliable), and up to two USB ports are freed up for other purposes.

Although it now has a standard microSDHC compatible memory card slot, please note that the Raspberry Pi 3 can also be booted from a USB download.

Best use: almost everything that is not limited in size. The Pi 3 is the most powerful version, making it especially ideal for emulating retro games. or as a Kodi box

The Raspberry Pi 4 is expected to replace this model, but is not expected until at least 2019.

Raspberry Pi Zero Models

The third version of the Raspberry Pi was released to great fanfare in late 2015. The computer only cost $5 and was the first to be featured on the cover of a magazine! Measuring just 65mm x 30mm x 5mm and weighing a tiny 9 grams, the Pi Zero is perfect for any project where space and weight are top notch. It may be smaller than previous Raspberry Pi models, but using the Zero is as easy as

Original Raspberry Pi Zero

When the original Pi Zero was released, it marked a fundamental change in how the Raspberry Pi was perceived. The device was no longer limited by its size. The USB and GPIO ports have been reduced or removed entirely. Lightweight, half the size of the B+, the Zero is a powerful little computer nonetheless.

raspberry pi board guide

The Raspberry Pi Zero has a 32-bit ARMv6Z architecture with the Broadcom BCM2835 SoCs found in Models A and B+ Pis. Likewise, the processor is a 1GHz single-core ARM1176JZF-S, similar to the one found on the original Pis (but upped from 700MHz). It has 512 MB of total RAM, and boards with version 1.3 (released since May 2016) also have a MIPI camera interface.

The Pi Zero features a mini HDMI output and a microSD card slot, as expected, with a micro USB for power and another for data only. Stereo sound can be output via GPIO. Even though the GPIO pins are removed, the array — along with Run and TV I/O — remain. This means they can still be used, either by soldering or adding GPIO pins by hand (kits are available).