The Raspberry Pi Zero W

The air sensor connects via USB to a computer. For indoor use, hooking the sensor up to any computer would be good enough for spot readings, but our plan was to put the computers outside. We decided to use a tiny and very cheap computer called the Raspberry Pi Zero W.

Image from [1]
Raspberry Pis are bare-bones computers that cost between $10 and $50, but do not include screens, storage, or any peripherals—not even an electrical cable to power them with.[1] They do, however, run a full operating system, which makes them quite easy to use compared to the alternatives we considered for this device (notably Arduino).

We settled on the second-cheapest Raspberry Pi because we have very simple computing requirements. Though the Pi Zero W is very slow compared to any other modern computer, it is certainly capable of doing the computations we need. We did not use the cheapest Raspberry Pi, the Pi Zero (without a W), because we wanted our computers to be able to report wirelessly.

We were forced to purchase the Pi Zero Ws in kits, which included a case, a power supply, and a MicroSD card, because the computers alone are rationed out at one per customer. Unfortunately, this drove the price of each Pi up from an advertised price of $13  to $65 (CAD, including tax and shipping).

The Pi Zero W (which I’m going to call “the Pi” from now on) runs Raspbian, a free operating system, which can be installed using a utility called NOOBS. Raspbian comes with the free programming language Python preinstalled. We used Python to collect and manipulate the measurements from the SDS011 air-quality sensor.

Setting up the Pi is fairly straightforward if you have the cables and peripherals—but to do it over a graphical interface, you’ll need quite a few of those, including:

  • A MicroSD card writer
  • A USB hub
    • And a USB keyboard and mouse
  • A mini-HDMI to HDMI adapter
  • An HDMI cable
  • A USB OTG cable
  • A somewhat beefy USB power adapter

In addition, you’ll need a MicroSD card. These peripherals add considerably to the cost of the $13 Raspberry Pi if you don’t have them in a drawer somewhere.

There is excellent help available on the internet, particularly Reddit, to get you to the point where you can boot the operating system.


1. New product! Raspberry Pi Zero W joins the family – Raspberry Pi. Available at: https://www.raspberrypi.org/blog/raspberry-pi-zero-w-joins-family/. (Accessed: 30th May 2018)