The Raspberry Pi Zero may have been out for a while, but it’s proving perishingly hard to get hold off. Unless, of course, you’re right at the head of the virtual queue when the online retailers put their latest batches on sale. Still, the little micro’s scarcity isn’t stopping hackers from coming up with ingenious solutions to its other limitations — too few USB ports, primarily — and accessory suppliers from issuing add-ons.
Here’s one that (kind of) does both. Sheffield-based Circuitbeard’s case doesn’t only house a Zero, it’s also intended to hold an equally diminutive four-port USB hub. Think of it as a tiny bunk bed with the Zero resting on top and the hub’s main circuit board reposing on the level below.
The design is very reminiscent of Pimoroni’s Pibow: all laser-cut clear acrylic sheets and those annoying nylon nuts and bolts you can never tighten properly without smearing the thread. The circuit boards are each sandwiched by a couple of acrylic sheets. The whole assembly is held together by four bolts at the corners. The Zero is fixed to its base-sheet with four smaller bolts which you’ll need to cut down to size once they’re in place. The hub is held in place by a bolt that runs between two of the USB connectors and by gaps in the base sheet which trap solder points on the PCB. Small circular spacers stop the corners pulling in when you tighten the main bolts.
Circuitbeard supplies two top-sheets: one with a gap cut to make room for GPIO pins and a second that covers the Zero entirely.
You have to figure out what goes where yourself, but there’s a set of photos of the complete unit on Circuitbeard to work from. The various lumps and bumps on the two circuit boards guide you too. To be fair to Circuitbeard, the case started life as a design anyone could download and use for themselves. It was demand from the laser cutter-less that prompted the case’s evolution into a retail item.
It should be no surprise that the case doesn’t come with a Zero, and the hub is extra too. You’ll need to pull it apart to free the circuit board, but that’s not hard. It’s a specific model of hub: the LogiLink UA0160, but Circuitbeard says you can use the Belkin F5U404 instead. You can find either on eBay.
I used the Belkin. Unfortunately, it’s not exactly the same as the Logilink. A couple of extra surface-mount components on the base of the board prevented it from aligning with the case’s base correctly, causing the base to bend slightly. These components aren’t present in Circuitbeard’s photos, so I’d recommend you go for the UA0160. Also, according to my multimeter, the Belkin is only outputting 3.3V from the power pin the tutorials indicate (unlike the IA0160, I believe), but there is a 5V point elsewhere on the board.
With the case assembled and fully laden, you can use a supplied mini-to-micro USB cable to connect the hub to the Zero. There’s room within the curve of the short cable for an HDMI adaptor. But it has to be said, getting the Zero’s Micro SD card in and out of this case is a pain. If you need to re-flash your card, you’ll need tweezers or plenty of patience while you disassemble the case.
You can hook up the hub’s own AC adaptor if you need hub power. Or you can wire a couple of tiny pins on the bottom of the hub’s PCB to two pads on the underside of the Zero, and feed power to the hub from the Zero, or vice versa. Trouble is, you still need the external cable for data, so all it does is save you a second power cable.
It’s also possible to run a couple of wires from other pads on the Zero to a different bit of the hub and do away with the USB adaptor cable altogether, but the case doesn’t expose that part of the Zero. That said, if you’re up for the soldering anyway, you shouldn’t have too much trouble drilling the case to create the holes you need for the USB data wires to pass through.
My soldering’s not quite up to the task, alas, so I’ll stick with the cable and bus-powered devices: a WiFi dongle and, occasionally, a keyboard. The external cable is a but ugly, but no worse than a dangly USB on-the-go cable and an external hub, powered or otherwise.
Circuitbeard’s case makes for a much neater, more readily portable package. I like it.
More Info Circuitbeard