4 layers221 × 71.5 mm

Hoatzin
mizzan-microtonal-piano/hoatzin
Hoatzin V1 Rev A from @mizzande is an encoder for the Fatar 88 keys supporting VFP3/15 3 pedal and aftertouch. The board offers connection over both standard MIDI and USB MIDI.
61 parts
Boards in 1 GitHub repository, designed in KiCad, that use the SN74LS14D by Texas Instruments (0℃~+70℃ 1 1.9V 2.7V~3.4V 22ns@5V,15pF 4.75V~5.25V 400uA 500mV 500mV 6 74LS 8mA Schmitt trigger 噪声抑制功能 SOIC-14 Inverters ROHS). See how each wires it, with its parts, size, README and files; the SN74LS14D’s symbol, footprint and pinout are on its own page.

mizzan-microtonal-piano/hoatzin
Hoatzin V1 Rev A from @mizzande is an encoder for the Fatar 88 keys supporting VFP3/15 3 pedal and aftertouch. The board offers connection over both standard MIDI and USB MIDI.