VFD Modular Clock (with IV-17 tubes)

The VFD Modular Clock is a clock based on old-fashioned VFD Display Tubes.

VFD is short for Vacuum Flourescent Display. A VFD display is typically green or blue, and emits a bright light with high contrast. VFD Displays are often found in car radios.

A VFD Display tube looks like an old Vacuum Tube, the predecessor to the transistor. The inside of the tube contains segments that can be lit up to form numbers and letters. Most tubes contain segments for one digit, and several must be stacked together to make a complete display.

The clock itself is modular, it comes with a base board, which is powered by an ATMega328p microcontroller and contains a high-voltage VFD driver that is used to light up the display shield that sits on the top board.

Shields
Currently, only one shield is available, but others are in production. Each shield is coded with a 3-bit numerical indentifier. This allows the firmware to automatically recognize the shield that is plugged in and it will adjust the display automatically. Support for shields added in the future will be released as firmware upgrades.

• IV-17 Display Shield: Contains 4 large alphanumeric 16-segment Russian VFD tubes. The display is blue/green.

Features

• Modular design: The display tube shields are swappable
• HV5812 VFD driver with 20 outputs: Can drive up to four 16-segment alphanumeric displays or twelve 7-segment numerical displays.
• Open source firmware (available at GitHub)
• On-board ISP header for upgrading firmware (requires separate ISP programmer)

Firmware
The firmware has shield detection built in, so it knows which Tube shield is plugged in, and adjusts the output accordingly. With the IV-17 alphanumeric display shield, you get four alphanumeric characters.

Enclosure not included.