The hardware consists of 4 main parts: the PCB, the plate, the bottom, and the keys themselves (switches + caps), all of which can be easily substituted with variants, making for a supremely customisable keyboard.
The main principle that drives the use of small keyboards like the Planck is the application of virtual layers, which effectively multiplies the number of available keys. The QMK firmware makes this easy.
Being a programmer, I opted for a layout that is mostly symmetrical, is thumb-oriented, and makes accessible those characters that frequent programming languages. I tried not to mess with the confines of the alphabet keys, and attempted at reducing, as much as sensible, the pinky finger's reach.
Modifiers are pushed to the edges, and the most frequently used ones – Control, L1, Alt, and Shift – are assigned to the thumbs and pinkies. The "L*" modifiers are layer changers.
For the alphabet key mapping, I like to use a custom one instead of qwerty. But rather than hardcoding the keymap into the firmware, the switching has been relegated to the operating system (ie. setxkbmap or xmodmap) for better compatibility with my laptop's builtin keyboard.
Holding onto the L1 key temporarily changes the layer or mode of the keyboard, thereby causing the indicated keys to hold these new values.
Certain decisions and sacrifices were made based on priority and personal preference. For instance, the backslash and pipe keys occur in this layer instead of the base layer. Also, the numerals are situated in the top row, rather than in the home row.
The navigational and multimedia keys are defined on this layer.
All the "L*" layers are a work in progress. But this is especially true for the L3 layer which holds only a few redundant keys and barely sees any use.
Tap to enter a character, or hold to enable a modifier. The firmware provides this neat functionality, and it allows one physical key to represent a character and a modifier simultaneously. Refer to
ACTION_MODS_TAP_KEY() in the QMK sources.
Before this keyboard, I was never truly complete.
I acquired the Planck in March of 2017, and I immediately found that the keyboard Does Things Right. Its simple design coincided with my sensibilities, my needs, and what I deem to be logically proper.
The linearity of its keys has posed no ergonomic difficulties, while its form-factor allows for happy portability and a consistent experience wherever I use my laptop. The open firmware readily handles my requirements and includes a few features without which typing on the Planck would have been far less pleasant.
The four keys in the lower corners (the ones that don't have modifier assignments) are blindspots to the fingertips. These keys are difficult to reach using either pinky or thumb.
They are quite accessible, however, with the edge of the palm. And during quick typing, the occasional corner palm jab mixes in a drum-like, syncopated feel to the typing experience.
I picked the Cherry MX silent red switches because I value silence. I value it so much, in fact, that I attached rubber o-rings to every switch in order to further dampen the residual clicking noise. And the result was quite satisfactory on the noise front.
On the feel front, however, I initially felt the switches to be too easy to press and mushy and indistinct. But I kept with it because the benefit of noiselessness outweighed the low tactile resolution. After a few weeks, however, the perceived mushiness turned out to be not so bad, and I began to enjoy the soft presses, even more than on the laptop keyboard or any other keyboard I'd used hence. As with any physiological acclimation, my body seemed to grow more sensitive to the minutiae of its environment, ie. my fingers adjusted themselves to the keys. Pretty soon, the "too easy and soft" simply translated into "fast".