Found its a bit tricky to touch the tiny pads on the TTP229 without mashing adjacent ones so knocked up this little overlay to help. Might make some different ones yet. Added the rsdoc for designspark mechanical if you want to edit it, there is a another one there with dimpled key tops but it does not print well yet.

Here is the code I wrote for MPLABx to use it, easy to convert to arduino.

uint16_t scan_keys() {
uint16_t ky;
for (char cl = 0; cl < 16; cl++) {
KP2_SetLow();
ky >>= 1;
KP2_SetHigh();
if (!KP5_GetValue()) ky |= 0x8000;
// printf("%c", (ky & 0x8000) ? '#' : '.');
}
return (ky);
}

Wanhao

Wanhao Duplicator i3 Plus

No

No

200

30