October 25, 2021

Vintage VFD Calculator Turned Into Desk Clock

from hackster.io

In the 1970s, a variety of calculators were made using VFDs to display digits. While largely supplanted today by newer display technologies, there’s still something pleasant about the greenish glow these devices give off. Ahmed Ragab decided to turn his vintage calculating machine into a unique clock.

While actually driving a VFD could present some challenges, Ragab’s method sidesteps this altogether by leaving much of the former calculating machine’s electronics intact.

To produce digits from the display, the build hijacks the keyboard inputs via a series of 12 PC817 optocouplers that electronically "press" digits 0 through 9, along with a decimal point and a clear screen input.

The calculator’s new PCB also includes accommodations for an 18650 cell, as well as charge and boost electronics.

An ATmega328P-PU with an Arduino Uno bootloader controls device, along with a DS1307 RTC unit to keep accurate time. The ATmega reads the date and time from the RTC chip, and updates the display every 10 seconds.

There’s even a date mode button in the center that can be pressed to temporarily show the date, before reverting back to timekeeping after a set delay time.

Build files for the ibico 066 V1 are available on GitHub if you’d like to duplicate the project, or simply use it as a starting point. Meanwhile, you can see it in action in the video below!