Tube Time

Today’s massive, high-resolution, flat screen TVs offer a far better viewing experience than the old CRT TVs of yesteryear. They are such a big upgrade that, aside from some limited use by retro gaming purists, tube TVs are no longer of much value. With analog broadcasts long gone and digital streaming services taking over, the old niche they used to fill has disappeared.

But style cares little for practicality. The current big black rectangles have nothing on the design of older sets, not to mention the warm glow produced by electrons slamming into a phosphor-coated surface. Hardware hacker Mirko Pavleski loves the look of tube TVs, so when he came into possession of an old, portable set, he knew it needed to be given a new lease on life. His idea was to turn it into one of the most charming digital clocks that you will ever see.

Being a portable TV, it didn’t come equipped with any video inputs. So as a first step, Pavleski opened up the case and dug into some datasheets for the chips he found on the board. After some time, he found that some pins on one of the ICs could be co-opted to receive a composite video signal. With a little bit of soldering and some cable, the vintage TV could display a composite signal on its screen.

But to make the clock, that signal would also need to be generated. That proved to be the easiest part of the project, thanks to the TVout Arduino library. With just a couple resistors, this library can turn an Arduino’s GPIO pins into a composite video signal of exactly the sort that an older TV is expecting. In particular, Pavleski used an Arduino Nano, but other boards should work as well.

With the display working, the only thing left to do was program the clock functionality. A DS3231 real-time clock module was included in the circuit to keep time, and custom Arduino firmware was developed to display that time on the screen in an attractive way.

Not only did Pavleski make something beautiful, but he also showed how older hardware can be saved from the landfill and still fill a useful role in today’s world. Check out the video for full details on the build if you have an old TV sitting around that you’d like to put to good use.