Skip to content

Latest commit

 

History

History
83 lines (72 loc) · 3.8 KB

mitosis-partslist.md

File metadata and controls

83 lines (72 loc) · 3.8 KB
Raw

Parts / Bill of materials

  • Receiver module

    • 1 Receiver Interface PCB, OSHPark or other PCB house.
    • 1 Pro Micro controller. Leonardo Pro Micro ATmega32U4. Replaces ATmega328 Arduino Pro Mini
      • 5V/16MHz
      • ATmega32U4 CPU
      • 12 digital I/O pins (5 have PWM capable)
      • 4 analog inputs
      • 32 kB flash
      • 2.5 kB RAM
      • Micro USB B (?) connector
    • 1 nRF51822 wireless module (see keyboard halves list for full details)
    • 12 Straight 0.1" headers (2 x 6 pins) to connect receiver PCB to Pro Micro
    • 1 1117 3.3v regulator in SOT223
    • 2 1206 (3216 metric) 4.7k resistor array, labeled "472" Mouser.com
    • 2 SMD tactile buttons (Reset and Pairing)
    • 4 (optional) Right angle 0.1" header. 4 pins. Used for programming the wireless module on the receiver
    • 1 (optional) LED RGB diffused 4PLCC SMD. Looks like CLVBA-FKA-CAEDH8BBB7A363 or CLVBA-FKA-CA1D181BB7R3R3 should work fine. TODO: Verify

  • Keyboard halves

    • 4 Mitosis Keyboard PCBs (2 for plates, 2 for PCB)
    • 2 nRF51822 wireless module (Contains a Nordic Semiconductor 51822-QFAC1-1513AN SOC chip). It appears that these are single-sourced though Waveshare $7ea + $3 shipping, direct or $11 on Amazon.
    • 2 reverse polarity protection MOS FET (SI2302)
    • 2 CR2032 batteries
    • 2 x 4-pin Right angle 0.1" headers
    • 4 x 1-pin Straight 0.1" headers -- Used on either side of each battery
    • an (optional, low priority) LED can be added to existing pads on the keyboard halves. It could be used to aid debugging new wireless code.
      • 1 single, LED 0603 SMD.
      • 1 single, 3.3k resistor 0603 SMD.

  • Keycaps

    46 1U keycaps, with the following profiles (or for DSA they are all the same):

    |Profile| Qty | Description                                |
    +-------+-----+--------------------------------------------+
    | R1    | 10  | Q-P - main alpha keys                      |
    | R3    | 10  | A-; - main alpha keys                      |
    | R4    | 10  | Z-/ - main alpha keys                      |
    | R1    |  8  | Top row of thumb keys                      |
    | R2    |  6  | Bottom row of thumb keys                   |
    | R3    |  2  | Bottom, inverted, row of thumb keys        |
    +-------+-----+--------------------------------------------+
  • Other
    • USB cable to Micro USB. Short or long, depending on your intended use/placement.
    • 46 Cherry MX compatible key switches
    • 2 Neoprene, adhesive backed, 4x4", 3mm thick. To be trimmed
    • 1 (optional) 3D Print or off-the-shelf case for the Pro Micro receiver

Parts warnings:

There are two versions of the nRF51 board black (wrong) and blue (correct). The black board doesn't physically match the PCB footprint. The correct dimensions are: 17.0mm x 20.8mm. The bad dimensions are: 15.09mm x 20.07mm.

The angled headers one builder ordered have a couple of mm between the 90 degree angle and the plastic piece. When he cut these flush with the board, the remaining pin length was too short to connect the ST-Link wires to. His fix for this was to pull the plastic part off since the solder is strong enough to hold the pins in place. It would be better to get an angle header that has the plastic closer to the bend (but that would make soldering them from the top harder).

Tools, ancillary materials required

  • Soldering iron suitable for SMT soldering
  • Solder paste
  • Solder
  • Multimeter (continuity tester)
  • Exacto(tm) knife
  • ST-Link V2 (or clone) to program wireless modules
  • tweezers (for SMT work)
  • Black mylar tape, or electrical tape to cover top of plates and wireless module.
  • magnification
  • De-soldering equipment, in case something goes wrong