BUILD-A-PI by KM4ACK

RASPBERRY PI ZERO 2W

Today I put together a tiny computer for use with my portable radio gear. It's in the form of a Pi Zero 2W and I used KM4ACK's Build-A-Pi utility to put it together instead of using an image from the internet.

It took a long time to complete and no disrespect to KM4ACK, but in the end, I wished I'd just downloaded an image 😏

I already have the HAM-PI software collection which I built into my Pi400, but I was curious about seeing what could be done with the smallest Pi out there - the Zero. It's amazing how compact it is! After completing this Build-A-Pi project, I've decided that I'm going to write another HAM-PI image onto a spare card and keep it with the Zero as an optional boot up.

To keep the Zero safe from knocks and drops, to avoid static damage and to provide some RF protection, I put it into a small metal case. It also looks pretty darned cool too. I got both off eBay for paltry amounts.

Because I was opting to install all the software included in the Build-A-Pi option list, I needed to use a 16Gb card, but I only had a 32Gb SDcard from Kingston which results in around 23Gb spare (wasted) space.

The case by FLIRC measures around 70x35mm and is really nicely made. A heat-transfer pad is included for the processor and all the connector holes line up perfectly. You even get a little wrist-strap with it.

The Pi Zero 2W uses a Quad Core 64-bit ARM Cortex-A53 processor running at 1GHz which is around 5 times faster than the original Pi Zero. 512Mb of ram is included.

On the PCB is a power-in and a USB connector (both Micro USB), alongside a Mini-HDMI socket. At the bottom edge is your Micro SDcard holder. 

The built-in Wi-Fi module is encased in a metal enclosure to avoid stray RF effecting it - always good when using radios close by! This mini-marvel even has Bluetooth 4.2. What it doesn't have, is a built-in soundcard.

When buying a Pi Zero 2W, you must factor in a decent little 5V PSU. One of the problems that people come across with PI's is lock-ups and black screens and it's almost invariably because they're using a cheap little usb charger from the £1 shop. The official mains supply has a 2.5A output which will allow your Pi to power other devices like a HDMI monitor and a wireless keyboard and mouse, etc.

Outdoors, you'll probably want to use a 5V battery pack or Power Bank. Depending on the capacity of it, it should last a good few hours in the field. I have a couple of Power Banks but the best one is a Baseus PD 20W which can power/recharge up to three devices at once. It has variable voltages which makes it useful for powering other devices such as QRP Labs QDX.

 

Once all the "building" of the Pi is complete (which is automated but can take hours), the device is ready to run all your favourite radio software. JS8CALL and WSJT-X work a treat. There's also GPS software which runs perfectly with my cheap GPS Dongle. This is essential for accurate time-keeping.

The Zero doesn't have the GPIO pin-out block, but it has all the connections to add one. Personally, I won't ever use that, so its absence is of no consequence to me. Also of no use to me is the camera-connector at one end of the pcb.

So, what's it like?? Well it works fine. There's no apparent problems with any of the software, but yes, it seems a tad sluggish compared to say the Pi400 - but then it would! In practical terms though, it works well and is certainly a lot smaller! 

MANUFACTURER'S SPEC....

1GHz quad-core 64-bit Arm Cortex-A53 CPU

512MB SDRAM

2.4GHz 802.11 b/g/n wireless LAN

Bluetooth 4.2, Bluetooth Low Energy (BLE), onboard antenna

Mini HDMI port and micro USB On-The-Go (OTG) port

microSD card slot

CSI-2 camera connector

HAT-compatible 40-pin header footprint (unpopulated)

H.264, MPEG-4 decode (1080p30); H.264 encode (1080p30)

OpenGL ES 1.1, 2.0 graphics

Micro USB power

Composite video and reset pins via solder test points

65mm x 30mm