Sub 100mm PCBs

PCBs that are under 100mm x 100mm

JLCPCB has special pricing for boards this size or smaller. $2 for 10 pieces with green soldermask. $5 for each additional small design in the same order. Shipping will be the largest part of the cost. Adding a small board to an existing order will only increase the shipping cost a few dollars.

Until recently, if you chose any color other than green the price would revert to the non-100mm special price. Now you can add color and just pay the additional fee for the colored solder mask.

You can also combine shipping if your previous order is still in production. The shipping for the additional boards from the new order will be combined with the previous order and will be much less than shipping a separate new order. I have done this twice to the same order.

I have many gerber files that are small enough for the special pricing:

• I-S-h0le - 4 key ISO enter macropad
• Arduino Six - 6 key arduino shield
• nori - 40 percent with backlighting
• 4x4X (Tetris) - 4x4 modular than can stack horizontally and vertically
• Green Eggs - Ring shaped macropad
• 5x5x9 - huge 225 key macropad made from 5x5 boards
• 5x5 - modular 60%
• GNAP 4x4 - GNAP split into 3 parts
• Pi - large circular macropad made from quadrants
• Lobot - Pro Micro ISP
• 4x4x4x4x4 - Modular 4x4, 4x8, 4x12, 4x16
• Christmas - LED Christmas ornament
• 25 - split 5x5
• 6lit - split 6 key macropads
• DeathStar - Circular macropad
• foobar - split 30%
• Onigiri - 6 key macropad shaped like a musubi
• RAWR - 6 key Domokun
• Half IOTA - split 40% with 16mm switch spacing
• 4 pack - 4 key macropad
• 2 pack - 2 key macropad

I-S-hOle

Made something for all those left over ISO enter keys

A small board with space for 4 ISO enter keys with PCB mount Cherry stabilizers. Powered by a Pro Micro.

I have a lot of left over ISO enter keys that came with cheap keysets from eBay.

Bottom of the PCB. The hole serves no purpose, though you could use it as a pen holder. You could assemble it upside down, but then the enter keys would face outwards. You could also use the 2u backspace or numpad plus/enter key caps.

The two PCB's are held together with M2 spacers and screws. The Pro Micro is mounted to the bottom.

There isn't a lot of space to fit the Pro Micro. I left the top two pins unsoldered since they might touch the metal stabilizer wire. Also, the bottom left corner pin is removed since it sits under the plastic stabilizer housing.

The Pro Micro is programmed with a simple Arduino sketch. Sketch and PCB files are on git.

Arduino Six

Six Pack Arduino Backpack

Six Cherry MX compatible switches on an Arduino Leonardo. Per key LED control.

This is the exact same circuit as the Six Pack, shaped as an Arduino Shield. It is designed for the Arduino Leonardo and it's clones which have the same controller as the Pro Micro (ATmega32U4).

Assembled and stacked on top a clone Arduino Leonardo. This runs the same Arduino sketch as the Six Pack.

Separated from the Arduino Leonardo. 

The PCB snaps in half. The top is a plate and the bottom is the Arduino shield. I wet sanded the edges smooth after snapping them in half. It is under 100mm square and can be made at a discount at JLCPCB. Files are on git.

I used the header pins that came with the many Pro Micros I have. The only other parts are the 2 resistors (if you want LEDs), switches and LEDs. If you use PCB mount switches you can eliminate the plate.

It is possible to use this with other Arduino boards based on the older ATmega328p (Diecimila, Duemilanove, Uno), but you would only be able to use it as a form of input for your sketch and not directly as a keyboard HID device. The USB connector on those other boards only provides a serial connection, used primarily for programming and debugging.