The Raspberry Pi is an unlikely success story. Originally designed as a tiny credit card sized computer to encourage programming it instead got taken to the heart of the maker and home modder community. Since their February 2012 launch they’ve sold over 6 million units and launched various models. Last November they went one better and started shipping the Raspberry Pi Zero for £4.

So what can you do with a £4 computer?

The Zero is not going to be a workable desktop computer. This is not a system to buy without any idea what to do with it but something to buy for a specific job.  It’s even smaller than the regular Pi’s and has less ports. It’s too small and too underpowered to run most applications but get Rasbian running on it and it is a real computer and can do one carefully chosen job.

Casting around a little online and I’ve seen Zero’s used as a retro gaming system, as a Minecraft server, as part of a motion detector, built into gloves as a controller, and as part of a sensor system for a fish tank. I decided to get technical and build a Tor node.

The Tor project is a system that lets people anonymise their traffic. It’s not perfect but is the best single way to get online anonymously available. It depends on a number of nodes spread throughout the world to bounce the signal. The more nodes you have the safer the system.

I found a number of sets of instructions online and realised how much I’d bitten off. Lets get this clear. The Zero (and other Pi’s) are not aimed at anyone without a reasonable amount of technical confidence. That said if you view it as an educational experience you don’t need to know much to start off with just to be willing to learn.

I also discovered that whilst the Zero can be adapted to uses like a Tor node it’s not what it’s optimised for. It’s small size mean’s it’s got scanty ports and no built in networking. You can add a USB hub (and I did) but that partially defeats the use of having a tiny footprint.

Zero details

Product Information

Price: £4

Included in the box: One Raspberry Pi Zero

Paid Extras: The Zero is a complete computer but it lacks power, any way to interface with it, networking or storage.

To use it you need some extra parts that you might have already. At a minimum you need a microUSB power in and charger (possibly from a phone), a MiniHDMI to HDMI connector, HDMI cable and screen to see on, a USB OTG cable and a powered hub and USB keyboard and finally a microSD card for storage.

If you want networking you’ll also need a USB wifi dongle or USB Ethernet port.

Most tinkerers will have a lot of this already available to use but if you’re starting off the real cost of having the Zero useable is more like £40.

Retailer: Element14, Allied Electronics or RS Online  +:

About The Raspberry Pi Foundation

The foundation was envisaged in 2006 as a way to fight the decrease in interest from children in IT – give them something to experiment with. Everyone was using GUIs with little idea about what underpinned it. The Raspberry Pi was born from this in 2012 and although popular in education is hugely popular amongst hobbyists. The computer, manufactured in Wales has sold over 5 million units since and is going from strength to strength.

The Ergohacks Evaluation


The Zero is the smallest Pi available both in terms of its size and its specification. It’s most suited as a system to be built into a sensors or wearables because of this. If you are looking for something to be online permanently or to have multiple fixed sensors attached it may not be the best choice.

It’s low initial cost (if you’ve got the extra parts available) makes the Zero almost disposable in the right situation. The classic use of that would be attached to a camera and balloon to get so great pictures but there are other ideas out there as well.

Ergonomic Design

The Zero’s big plus is its tiny size. Before you start plugging cables in you can literally hide it in a closed hand. This means that it could be fitted in many unexpected places which is great for something that can be used as a sensor controller.

Environment & People

The Zero uses standard circuit boards and chips and is no more or less environmentally friendly than most IT equipment. There are a number of uses of the Zero which do have environmental benefits. The most obvious use I’ve seen was a Zero with a thermometer added on attached to a chest freezer being used as a fridge.The Zero controlled the power of the freezer keeping it at 4 Degrees Celsius making it a perfect and very efficient fridge.


The £4 headline price of the Zero is somewhat deceiving. The computer is that price but you need a number of other parts to get it running. If you have these lying around or borrowable that’s great but at the very least you’ll need a dedicated power supply and a microSD card which will cost another £10.

Even at that price the Zero is amazingly cheap for something that a decade ago would have been desktop technology.


Technical Specification
Processor: 1Ghz, Single-core CPU
Size: 65mm x 30mm – without any connectors

Operating System: – None included
Network: None built in
Memory: 512MB RAM
Display: Mini HDMI out
Connectivity: USB OTG
Power: MicroUSB
Other: HAT-compatible 40-pin header and Composite video and reset headers


Zero Hand


The Raspberry Pi Zero is marketed as a cut down Raspberry Pi. To get to that smaller form factor and smaller cost they had to make a number of compromises and the resulting system has advantages – it’s cheap cost makes it even easier to experiment with and the small size means that you can fit it in to some very unexpected uses. The lack of ports – particularly built in networking – does hurt its flexibility for many more traditional Pi uses.

If you’re after something very cheap to play with, want a Pi to hook up to sensors or are willing to put up with a bundle of cables the Zero might be for you. If you’re looking for something to attach to the network permanently it’s big brothers might do better. Recommended for sensors and first time dabblers.

Finally – that Tor router I was building?  Success!

The review is based on the Raspberry Pi Zero. This article was first published on the 5th February 2016.