3D Print A Colour TV

The oldest form of television used a spinning disk with a progression of holes -- a Nipkow disk -- to slice the image into lines for display. They're surprisingly simple machines and capable of unexpectedly high-quality images despite their relatively low resolution. Even better, in an age of microcontrollers and bright LEDs, making one that works is not the chore it might once have been. [James Provost] has created one that uses an Arduino Mega and a set of 3D printed parts, so there's no excuse for not having a spinning disk TV on your shelf.

The Arduino Mega is chosen because it has enough lines to drive three six-bit DACs for each of red, green, and blue. The disk is driven by a PWM motor controller, and synchronisation is taken care of by a piece of reflective tape and an IR proximity sensor. Images and video are read from an SD card and displayed on the screen in glorious 32-line colour. The full build process can be seen in the video below the break.

A surprise when viewing mechanical TV is that its quality is much better than the meager resolution would have you believe, and this one with its colour display is much better than the usual monochrome devices. It's hardly HDTV, but it acquits itself well and would provide an excellent talking point.

If you're curious about Nipkow disks, they're a subject we've examined in the past.

#arduinohacks #arduinomega #colortv #mechanicaltv #nipkowdisk

Retrotechtacular: Mechanical TV From The People Who Made It Happen

If we have a television in 2021 the chances are that it will be a large LCD model, flat and widescreen, able to display HD images in stunning clarity. Before that we'd have had a CRT colour TV, them maybe our parents grew up with a monochrome model. Before those though came the first TVs of all, which were mechanical devices that relied on a spinning disk to both acquire and display the image. The BBC Archive recently shared a vintage clip from 1970 in which two of the assistants of [John Logie Baird], the inventor of the first demonstrable television system, demonstrated its various parts and revealed its inner workings.

We've covered the Nipkow scanning disk in a previous article, with its characteristic spiral of holes. We see the original Baird Televisor, but the interesting part comes as we move to the studio. Using the original equipment they show a dot of light traversing the presenter's face to scan a picture before taking us to a mock-up of the original studio. Here there's a surprise, because instead of the camera we'd expect today there is a Nipkow disk projector which traverses the subject sitting in the dark. A bank of photocells above the projector senses the reflected light, and returns a video signal.

The resulting low-resolution pictures had a low enough bandwidth to be broadcast over an AM radio transmitter, and for a tiny 30-line picture in the glowing pink of a neon light they provide a surprising amount of detail. With such a straightforward principle it's not surprising that they've appeared in a few projects on these pages, including an Arduino driven colour video monitor, and a POV clock. Take a look at the video below the break.

#OnThisDay 1930: The first, experimental TV play was transmitted from John Logie Baird's studio.

40 years later, two of Baird's assistants - Tony Bridgewater and D.R. Campbell - demonstrated how mechanical television worked, on Review.

Fascinating stuff! pic.twitter.com/F6YFDAOAUg

-- BBC Archive (@BBCArchive) July 14, 2021

#retrotechtacular #baird #mechanicaltv #nipkow #nipkowdisk #tv