Manuel Tosone's Nixie Alarm Clock Bathes You in Its Warm Glow While Waking You with Music

Electrical and mechanical engineer Manuel Tosone has built a retro-aesthetic alarm clock, which combines vintage Nixie tubes for the time display with the ability to play back saved music tracks as an audible alarm.

"Wake up to your favorite tune and the warm feel of neon light," Tosone writes of the project. "This [clock] uses IN4 Nixies driven in biquinary mode and neon lamps. The idea is to have an alarm clock where you can load songs on an SD Card and every time the alarm goes off, one of those songs is chosen at random and played through the speakers."

Based on vacuum tube technology, Nixie tubes — also known as cold cathode displays — use glow discharge to provide a warm light as they display the information of your choice. In Tosone's case, it's the numbers of a clock — but the vintage display tubes are only half of the project.

"The clock is made of two PCBs housed inside a 3D-printed enclosure," Tosone explains. "The display PCB has all the circuitry required for driving the nixie tubes and the neon lamps. This includes a 180V boost converter to dive the anodes, shift registers to interface with the baseboard, and high-voltage transistors. The base PCB is where the magic happens. There is an SD Card where the songs are stored, a PIC24 microcontroller that drives the display and reads data from the SD to drive a 16-bit DAC through I2S, and a stereo class D 2×3 W audio amplifier."

Tosone's design includes a current source for the Nixie tubes, which provides a couple of advantages over simply putting a resistor in the circuit: "You can change the brightness on all the Nixies by turning a potentiometer," he explains. "The second advantage is that when the tubes get older the operating voltage increases, driving them with a current source will, at least in theory, make them have the same light output even at the end of their life."

More information is available on Tosone's Hackaday project page, while schematics for both boards have been uploaded to GitHub under the reciprocal GNU Affero General Public License 3.