Friday, September 9, 2016

Mini Planck

Tactile Omron switches

  • 12mm Omron tactile switches
  • 180 gram fake ones from eBay (Yellow)
  • 130 gram real ones from Mouser (Cream)
  • Arduino Pro Micro
  • QMK firmware 
  • LUFA Mass Storage Bootloader
  • Cheap ABS keycaps from eBay
Wanted to make a smaller Planck. The only reasonably easy to obtain switches in a smaller size are these 12mm tactile switches. Metal dome construction. Loud click. Typing on these are horrible. The pressure required for the 180 gram is more than any Cherry switch. The 130 gram is much less. The switch travel is less than 1mm. They would make a nice macro pad or maybe used on a game pad, but not good for touch typing.

The cheap fake yellow Omron's are supposed to be 180 gram according to Omron, but since they are fake, no idea what they really are. They are definitely much harder to press than the 130 gram ones from Mouser. The genuine Omron from Mouser are rated for 3 million cycles. They also have a high reliability version rated for 10 million cycles.

Two styles of keycaps available for these. Round circular caps and square re-legendable ones. The fake Omron switches allow the stem to rotate and the square keycaps were always crooked. The real Omron ones allow for very little twist.

PCB's were made at Two PCB's used in a sandwich with 5mm spacers. The Pro Micro is soldered to the bottom of the top board. The bottom PCB is just for support.

Very basic 4x12 matrix..

Compared to a Planck it is very thin and slightly smaller.