MIDI Guitar Hardware Update
Donor guitar
- Fender Squier Telecaster (25.5″ scale, 21 frets)
- Chosen for its bolt-on neck, roomy control cavity, and low cost
- An initial check showed 18″ from the nut to fret 21, which matches the theoretical 25.5″ scale layout
Fret sensing plan
- A custom flex PCB overlay sits on the frets, with 126 pads (6 strings × 21 frets)
- Each pad has its own trace, and the grounded string pulls a pad low when pressed
- This lets us detect chords with several strings on the same fret
Measurements we’re collecting for the PCB layout
- Nut-to-fret-crown distances, checked against the calculated fret positions
- Fret crown width, height, and length
- Fretboard width at the nut, fret 12, and fret 21, plus the fretboard radius
- Each string’s lateral position at frets 1, 12, and 21, plus at the nut and saddle
- String gauges and nut-to-saddle distance
- Baseline string action, to plan for the overlay thickness
Pluck and velocity sensing: Roland GK-3
- We selected the Roland GK-3 divided (hexaphonic) pickup, which gives a separate signal for each string
- It mounts without drilling, so the stock bridge stays in place and each string’s ground path is preserved
- It also makes the setup reversible, which suits prototyping
- Our own ADC and firmware will read the six signals for pluck timing and velocity
- Still to confirm: breakout box and cable, mounting position on the Tele, and ADC front end
Next steps
- Finish the measurements and generate the pad layout
- Order a test flex PCB, and prototype the scanning firmware on a bench board first