To use four NeoSliders on one I2C bus, each board needs a unique address. You will cut the traces on three of the boards to set them.
Set them to:
- 0x30 (default, don't cut any traces)
- 0x31 -- cut trace A0
- 0x32 -- cut trace A1
- 0x33 -- cut traces A0 and A1
More info is available here.
The NeoKey 1x4 has a default I2C address of 0x30 so to prevent a conflict, you can solder the A3 jumper closed, changing it to address 0x38 as shown here.
Insert the keyswitches through the keyplate (3D printing file linked above), minding the orientation so they'll fit into the hot swap sockets. Position them so the "window" in the switch is above the reverse-mount NeoPixels.
Then, carefully align the legs with the NeoKey board and insert them all at once, squeezing with even pressure.
Cut the Enclosure
Use the linked .ai file (it is the blue .zip file above) to cut the case parts from acrylic. You can do this on a laser cutter or CNC machine, by hand with a saw and drill (print the .ai as a template), or send the .ai file to a service bureau for cutting. You can also use the .pdf file that includes dimensions for other cutting methods.
Mount the NeoKey onto the screws as shown, by threading the nuts on first, and then sliding the board and keyplate holes over the screws. This places the board at a good height and it will stay put in use, no need for longer screws or top nuts.
Mount the Feather
Use short screws and nuts to mount the feather board as shown, with the USB port facing the back of the board, over the notched cutout.
Mount the M3 standoffs from the bottom with short M3 screws.
Place the top plate over the controls, then secure with four more screws.
Plug in USB and you're ready to go!
Plug in the Neocontroller to your computer over USB-A to USB-C data/power cable. For typical MIDI use, simply select the Feather RP2040 MIDI device. To use with Lightroom Classic, first download and install the free MIDI2LR plug-in as shown here.
There are plenty of good setup and configuration videos out there, such as this.
Here it is in action: