Writer Deck::Keyboard v1

Writer Deck::Keyboard v1

Hi my imaginary reader,

As I wrote last post, I did indeed finish designing the keyboard for my DIY Laptop. This is like the second or third keeb I designed so many things were quite easy, although the space constraints were somewhat interesting: my layout was constrained by my desire to have a standard ANSI keyboard that I could blindly switch to and from compared to my current YUNZII. But no more space than that strictly necessary was allowed. This lead to some interesting routing and a very very tiny logic circuitry area.

Full PCB layout as a screenshot taken from KiCad featuring a standard ANSI layout keyboard with an extra row as described below. Includes measurements that will be detailed below and functional labels all of which are described in the next alt-text except for the one saying "Mistery Gap (I cannot figure it out), which points to a 0.3 mm gap between they board edge and the rightmost key edge. The gap is present on rows 2,3,4,5 but not on 0,1

Obviously I used a RP2040 as I plan to flash QMK and not bother myself with coding a whole keyboard firmware: I'm already reinventing one wheel with laptops

Image depicting a corner of the board populated by SMD components. From left to right: 8 pin Hirose FFC connector labeled "FFC-over-USB", AMS11173v3 Low Dropout regulator, tactile pushbutton labeled "FW flash button (USBBOOT), 8-pin TSOP package labelled "QSPI Flash", 56-pin LQFP package labelled "RP2040 MCU", tiny unlabelled crystal oscillator 12MHz. Diodes and resistors omitted
Detail of the logic circuitry area

One thing that is stumping me tho is the pointing device: currently there is none attached, and I was thinking of maybe just using a trackpoint (I saved a 1U slot for it) since everything that has to do with PCB touch technology tends to give me a sense of exhasperation and parasitic-capacitance paranoia, which would have not meshed well with the aforementioned size requisites

The only deviation from the standard ANSI layout is a partial extra row at the bottom comprising four (4) thumb-keys under the spacebar, aligned with C,V,N,M, and the arrow keys Left, Down, Right. I came to this solution since horizontal space was at more of a premium, and by measuring my thumbs' reach it was clear that there was an underutilized arc of space under the spacebar. I plan to use these thumb-keys for navigation tasks if I figure out a pointing device, otherwise they can be macros or whatever. The arrow keys are probs going to be a bit uncomfortable, which is good because I am particularly bad at using HJKL to navigate my editor when the arrow keys are too easily reachable. I only included them for compatibility

Have some screenshots!

Pretty standard 14 columns (labelled 0-13) by 5 rows (labelled 0-4) keyboard matrix. The switches are labelled SW1-SW70 and each of them as a diode to make NKRO and anti-ghosting possible. The schematic is a hierarchical sub-sheet in KiCad and the column/row labels are Hierarchical pins that will be exposed in the root schematic
The Key matrix schematic
KiCad Schematic detailing the connections between the RP2040 MCU, its accessory components, and the keymatrix aboxe
The Root schematic (mostly logic and power)
Detailing the flavor text between the rightmost thumb-key and the leftmost arrow key. The text reads (| means line break): "Writing Laptop::Keyboard | Made this instead of continuing my manuscript | The ultimate procrastination! | | To quote R. Stallman: Happy Hacking!"
The featured image again with more alt text