Viterbi Keyboard - 5x7 70% Split Ortholinear

Viterbi Keyboard - 5x7 70% Split Ortholinear

Regular price $19.99 Sale

5x7 70% Split Ortholinear keyboard, more keys for more fun!

Note the build for the Rev. 2.0 is a bit different than the previous revision. Both of the Pro Micros are oriented the same way with the flat side of the Pro Micro facing the bottom of the case, similar to how it's done with the Quefrency. Revised build guide currently in progress.

Item Notes

The PCB Kit includes the following:

  • 2 Viterbi PCBs
  • 2 Push buttons for reset
  • 2 4.7kΩ resistors for I2C
  • 2 TRRS jacks (no need to buy separately)
  • 70 1N4148 diodes
  • LED support kit already included
    • 2 MOSFET
    • 2 1kΩ resistors


Each half of the board is a 5x7 matrix, but there is the option to have a 2u key in the lower left and right corners in place of 2 1u keys. The spot for the 2u has holes for Cherry PCB mounted stabilizers.

There's also a spot on the PCB for a pushbutton switch to reset the Pro Micro for flashing. No more taking a wire/tweezers/screwdriver to jump the Reset and GND pins!

The Name

As usual with these split ortho boards, we had to christen the board with a term from bakingpy's past. He used to implement the Viterbi Algorithm a number of times to take 2N received bits from a communications signal and figure out the original N bits it was encoded from. So here, signals from 2 board halves, decoded into one board, it's like this thing named itself.


The Viterbi uses QMK for its firmware, and the code for it has been merged into the main codebase. You can find it here: QMK - Viterbi directory.


Here's the case files for a sandwich-style case are still under development: Viterbi Case on GitHub

    The kerf setting was set to 0.15mm for use with Lasergist and Ponoko.

    Items needed for build

    • 35 Diodes per PCB (through-hole and SMD diodes supported)
    • Arduino Pro Micro or Elite-C (you can mix and match)
    • 2 Push buttons (included with this item)
    • 2 4.7kΩ resistors if using I2C (included)
    • Switches - Alps or MX-compatible
    • Case/Plates
    • 2 TRRS Jacks (included with this item)
    • Optional parts for LEDs
      • 2 MOSFETs (included)
      • 2 1kΩ resistors (included)
      • 70 470Ω resistors (sold separately) 
    • TRRS cable
    • Micro USB cable
      • Optional - 2u PCB mount MX stabilizer if using 2u keys

        Build Guide: Viterbi Build Guide