A mini mechanical keypad with light-up keys.
Honey, I shrunk the keypad. The Keybow MINI is a three-key version of the original 12-key Keybow reviewed in issue 79. This time you need to supply your own Raspberry Pi Zero (with a GPIO header), but otherwise the principle is the same: connect the keypad to another computer – with the supplied micro USB to USB-A cable – and you can customise the key mapping to use it for a wide range of purposes, such as a games controller, hotkey pad for applications, or to insert text/code snippets with a single key press.
This article first appeared in The MagPi 83 and was written by Phil King
Solderless assembly is very similar to the original Keybow and only takes 10–15 minutes. After attaching your Raspberry Pi Zero to the PCB and acrylic base, you simply push-fit three switches into a key plate (making sure they’re all orientated the same way) and add the translucent key caps before slotting into the PCB.
As before, you’ll need to supply your own microSD card for the tiny (26.6MB) Keybow OS. Upon connecting the Keybow to a computer via the USB OTG cable, the OS is loaded into a RAM disk and it boots up in just 10–15 seconds.
Unlike with the full-size Keybow, we had no problem inserting the cable into Raspberry Pi Zero’s USB OTG port as the latter is now situated on the edge of the device rather than tucked away inside.
Once connected, the keys light up in an animated rainbow pattern (determined by a PNG file). To change this, and customise the key mapping, you need to slot the microSD card back into your computer and edit a Lua file to select a sample key layout or your own custom one, as explained in the online tutorial. As noted there, you do need to add a few lines to the default Keybow layout code, and alter some function names, to make it work on the MINI. Alternatively, there’s now a Keybow Python library that can be used within Raspbian to light and map the keys.
Either way, the real power of the Keybow MINI lies in the ability to create advanced macros to trigger a whole series of key combinations and presses with just a single key press.
Considerably less expensive than the full-size Keybow, with the same functionality, just fewer keys. It looks cool when lit up, features a nice key action, and has multiple possible uses.