What is it?

A standalone clock built around the quirky vintage IV-22 vacuum tube displays, showing six digits in HH:MM:SS format. An STM32 processor runs the clock, with a switching regulator to generate the necessary voltages. An optional header accepts a common NEO6 GPS chip for perfect time synchronization, otherwise time can be set manually. Supports display dimming to eight levels. Supports battery backup so the time is kept even when unplugged. Completely open source hardware and software design.

What you get

• The double sided circuit board.
• All electronic components, including both surface mount and through hole and a pre-programmed microprocessor.
• Solder paste stencil.
• Six IV-22 display tubes (plus at least one spare) including pin sockets.
• A laser cut acrylic stand for holding the clock at a convenient display angle, with attachment hardware.

What you need

• Standard electronics kit gear (solder, soldering iron) and skill.
• A small amount of solder paste, or a steady hand, for the surface mount components.
• An AC adapter: no more than 20 volts, but the higher the better. Easily available 18 volt adapters are good.