Electronics: Raspberry Pi Zero W
The computer I’ve used to run Akiniscope is a Raspberry Pi Zero W. This has most of the facilities I need, and is small, cheap, and uses little power, which could reduce the size of the power supply I use.
I went for one without headers for connecting the digital inputs and outputs, the GPIO, so I could solder wires on to it, which takes up less room, and involves less parts.
It has a header for a camera, which I defiantly need. It doesn’t have an audio out, like some of the larger models, I could add some electronics to create an audio output on one of the GPIO pins, but decided to use a USB audio dongle.
The W in the name means it has WiFi. I was unsure whether to use this or not. Once installed though, how would I communicate with Akiniscope? WiFi seemed the easiest answer. What would I need these communications for? Updating the software, in the early stages, retrieving logs, for fault finding, and archiving, or deleting, the pictures taken by Akiniscope. One can never guarantee network connection at a random location, so I’ll make Akiniscope it’s own WiFi node, and not name the node as Akiniscope, but something uninteresting.
So, has the Zero W got anything missing? A Real time clock. If you have an internet connection, then computers can synchronise time via NTP. Desktop computers have a bit of electronics and battery, which is called a Real Time Clock (RTC), but to save space and complexity, the Raspberry Pi doesn’t have one of these. So, why do I need the correct time within Akiniscope? The one thing that needs it is logging. I’m still debating with myself whether to add a RTC, or not.
Nov 2021 Update
Raspberry Pi Zero 2 W is available. Am I going to swap to that? Of course I am. Everything runs really swiftly now. What a wonderful little device.
When I upgraded, I also changed how I connected all the GPIO. I used a RasPiO Breadboard Pi Bridge. To connect to the Raspberry Pi Zero 2 W, rather use the 40 pin socket header that comes with it, I used a 40 pin boxed header, this enabled me to attach via a ribbon cable, helping me with space on installation.
