Phi

nixie-macropad

Simple 2x3 macropad with encoder that has a 3 digit nixie tube display that can be programmed for various functions over QMK.

Usage:

Feel free to try replicate with care, as this is an unpolished proof of concept that I will probably build on later. Enjoy!

Hardware Notes:

• Not sure but it seems the boards that I am using to drive the Nixie tubes might be discontinued. However the developer open-sourced them, so you might be able to make them yourself. (Planning to make my own for future builds)

Main Features:

• 3x IN-14 Nixie Tubes with numbers 0-9 plus left comma
• Uses QMK
• Display current volume of connected Windows device via RAWHID
• EC11 Encoder + button
• 2x3 Macropad with Kailh Hotswap
• Only USB connected to PC needed

Software Installation:

Windows Node Script:

1. Download the 'Node Script' folder
2. Follow the steps in 'Development Setup' and/or 'Using the Script' from BlankSourceCode's repo

QMK:

1. You need to flash the Pro Micro with custom QMK firmware
   • Fork: Use my fork
   • How to flash: QMK Docs
2. Build for Phi (Default)

Hardware:

Before Assembling:

1. For the Exixes, you need to attach the Nixie tubes to the boards.
   • I just soldered machine sockets to the boards and shoved the Nixie tube pins into the sockets (gingerly)
   • Or follow their recommended method

Assembly

1. Make the custom PCBs (needs 2, or make a case)
2. Solder on the required components below (see pictures)
3. Assemble such that two of the custom PCBs make a basic case thing
4. Choose some cool keycaps and knob

Bill of Materials:

• 2x Custom PCBS
  • Sandwich with 7x 15mm standoffs (M3 Size)
• 3x Exixe
  • Nixie tube driver modules with SPI communication
• 3x IN-14 Nixie Tubes with 0-9 digit and left comma (at least)
• 1x Pro Micro or similar pinout with QMK support
• 2x Custom base PCB that doubles as stand
  • See PCB build files
• 6x Kailh Hotswap switch sockets
• 1x 2.5-15VDC to 170VDC DC-DC convertor or similar
• 1x Any type of EC11 rotary encoder
  • I used this one
• 1x SMD 3.3V Voltage Regulator
  • Needed to power the Exixes
• 3x 10uF Electrolytic Capacitors
  • Required for the Voltage Reg
• 1x 0.1uF Ceramic Capacitor
• 7x Diodes
• 3x 470 Ohm SMD Resistors
• Some 2.54mm pitch connectors (if you don't want to direct solder)
  • I like machine sockets but normal 'Arduino'-esque ones are good too
  • 3x 7 pin for Exixe comms
  • 2x 12 pin for Pro Micro
  • 7x 1 pin (if you can find them or just cut bigger ones)
    • For 170V DC-DC convertor and Exixe 170V
  • 2x 2 pin for Exixe 3V
  • For the above 2, you can also just get 7 pin ones and take out the middle 4 pins
• Some keycaps
• An encoder knob

Additional:

Housekeeping:

• Every ~15 mins the tubes will cycle all digits to reduce change of cathode poisoning

Future Work:

• Possible adding VIA capabilities for flashing
• Adding more uses for the 3 tube digits; current weather, CPU usage etc
• Adding another digit for RTC time
• Bluetooth/Wireless with battery

References:

• Exixe
• RAW HID communication via node script