Do you like being rudely awakened by a blaring alarm clock in the morning? We’re not exactly fans either, but perhaps seeing this VFD alarm clock by Christine Thompson would make things just a little more tolerable. The device uses a Soviet-made IV-27V tube sandwiched between a pair of 20mm copper elbow joints, situated on top of a nice wooden base.
It’s an elegantly simple design exterior-wise, and the elbow joints conceal an array of wires emanating from both sides of the display tube. Inside the base, a MAX6921 chip sends control signals to the segments, but because of its limitations, only 10 of the 13 characters are used. While maybe another driver chip could be implemented here, 10 characters is plenty for this application, displaying time, date, humidity, temperature, pressure, and the words “WAKE UP!” to accompany an audible alarm.
An Arduino Mega runs the overall clock, along with a RTC module to keep track of time. A keypad is added on the back for user interface, as well as a supplemental 16×2 LCD display. Power requirements are a bit complicated here, with 24V needed to power the VFD tube; 5V used for the Mega, LCD screen, and speaker; and the 3.3V output of the MAX6921 driver chip and BME280 environmental sensor. Finally, the 12V actually fed into the device through a barrel jack is used for an LED lamp. Be sure to check it out in the video below, with the demo portion starting around 4:15.