v2 BOM

BOM

This is a premilinary BOM for the v2 lalboard. This is a "minimal" bom required for a single finished lalboard -- including 1 adjustable base and 1 static base. You'll likely want to get more than the listed quantity of various components (magnets, especially), to allow for test prints, etc.

You may also want to get a wider selection of 0805 resistors, to allow for adjusting the output and sensitivity of the IR LEDs, IR phototransistors and opamps, etc.

Magnets

• 98x 1/16" N42 cube magnets - kjmagnetics
• 8x 1x1x1mm n50 cube magnets - supermagnetman OR 1x1mm n50 cylindrical magnets ebay
• 30x 5mm n35+ sphere magnets - totalelement
• 186x 1/8" x 1/8" x 1/16" N48 magnets - totalelement

LEDs/Phototransistors

• 50x "IR908-7C-F" IR LEDs - digikey lcsc

• 50x "PT908-7B-F" IR phototransistor - digikey

• Some superglue or other adhesive of your choice, for gluing magnets in place - amazon

Capacitors

• 4x 10u 0805 capacitors - arrow lcsc
• 2x 4.7u 0805 capactors - arrow lcsc
• 2x 1u 0805 capacitors - arrow lcsc
• 10x .1u 0805 capacitors - arrow lcsc

Resistors

• 2x 390k 0805 resistors - arrow lcsc
• 2x 100k 0805 resistors - arrow lcsc
• 4x 10k 0805 resistors - arrow lcsc
• 8x 5.1k 0805 resistors - arrow lcsc
• 10x 2k 0805 resistors - arrow lcsc
• 10x 1.5k 0805 resistors - arrow lcsc
• 40x 270 0805 resistors - arrow lcsc
• 2x 56 0805 resistor - arrow lcsc
• 2x 100 0805 resistor - arrow lcsc
• 2x 120 0805 resistor - arrow lcsc
• 2x 150 0805 resistor - arrow lcsc
• 2x 180 0805 resistor - arrow lcsc
• 4x 22 0805 resistors - arrow lcsc

Ferrite Beads

• 8x 56 0805 ferrite beads - digikey lcsc

Connectors

• 4x usb-c connectors - LCSC
• 14x 7-pin jst-zh connectors - digikey LCSC
• 8x 7-pin jst-zh right-angle connectors - digikey LCSC

Other Elecronic Components

• 10x SOT-23 npn transistor - arrow lcsc
• 2x SOT-25 3.3v linear regulator - digikey lcsc
• 4x TSSOP-14 LMV324 op amps - arrow lcsc
• 4x SOT-23-6 TVS protection diodes - digikey lcsc
• 2x ESP32-S2-wroom/ESP32-S2-wrover modules - digikey lcsc
• 4x spst push buttons - arrow

Cables

Recommended. The softer silicone wire is much more flexible, which makes it a lot easier to route in the confined space between the keys and the central board. But it's a pain crimping all those pins. It took a while to get the hang of it, and even then, I still spent over 20 minutes per 7-wire cable. I haven't been able to find a source of pre-made cable assemblies using silicone wire.

• 20x 7-pin JST ZH female connector - digikey
• 140x JST ZH crimp pins - digikey
• ~50ft of 28ga silicon wire - amazon
• Crimper - amazon

OR

• 20x 7-pin JST ZH female connector - digikey
• 70x 6" pre-crimped wires (with stiffer PVC insulation...) - digikey

OR

• 10x 150mm 7-pin JST ZH-compatible cable assembly (with stiffer PVC insulation...) - amazon or digikey

Recommended tools

These are the tools I use and recommend, but, as always, there are many ways to skin a keyboard :)

• Fine beading awl - amazon. Useful for enlarging holes in the printed PCB bases, and for poking through and making holes in the copper once applied to the printed PCB base.
• Craft knife. I love my ergo kiwi, but ye olde xacto knife should be sufficent - amazon. But seriously, get an ergo kiwi. You won't regret it :)
• Soldering iron of your choice
• Flush cutters - amazon
• Tweezers - amazon
• Needlenose pliers. I found these in particular to be very useful when inserting magnets - amazon
• Parallel jaw pliers. somewhat optional, but also useful when inserting magnets - amazon