Spent the last week getting planes onto the screen of an old Sony TV/VCR combo that was headed for the tip. The little Uno generates the picture itself, just two resistors into the yellow composite input, and a tiny wifi board fetches the aircraft positions every ten seconds and tells it where to draw. Range rings, a dot and a heading line per plane, callsign underneath. It actually works, which still surprises me. The tricky part was timing. The screen redraws constantly, so if the data arrives mid-frame you get tearing and flicker everywhere. Fixed it by buffering the incoming commands and only drawing between frames. Also learned the hard way that the sync resistor value matters alot, wrong one and the TV rolls forever. Range is currently set to 20km which sounds small but we're under a flight path, so there's usually two or three aircraft up at any time. The callsign text is chunky and blurry on such a small tube, honestly part of the charm. Next I want to try colour, the TV has an SCART socket I haven't touched yet.
Got a dead-ish old CRT pulling its weight again as a live plane radar
Oct 11, 2026
Last reply: 1 day ago
6 Replies
I did something along the same lines a couple of years back with a spare Arduino and a little black and white portable I rescued from a garage sale. Mine just drew a clock and some weather numbers, nothing as ambitious as live aircraft, but the timing headache was exactly the same. I ended up waiting for the vertical blank before touching the buffer, same as you, and the flicker went away completely. Before that the whole screen would shudder every time new data landed and I nearly gave up on it. The sync resistor thing rings true too. I had a pair of 75 ohm and 470 ohm resistors off some online guide and my portable would not lock on at all. Swapped values around until it settled. Old CRTs seem to be forgiving one minute and fussy the next.
For the colour step, be ready for extra pain. I got as far as trying colour bursts on mine and the tint drifted all over the place depending on temperature. I gave up and stayed black and white, which honestly suited the little set. If your SCART input takes RGB rather than composite you might have an easier path, more pins but no colour encoding to fight with. Under a flight path with a couple of planes up sounds like the perfect use for it.
I went down a similar road with a Philips portable I pulled out of my mum's loft, only mine ran off an ESP32 doing the picture generation because I wanted more pixels for a flight tracking display of my own. The colour step is where I stalled out, so I'd say have a go at it but pick your battles. Composite colour means generating the phase information as well as the sync and luma, and getting the burst right on an Uno is a real squeeze with the timing budget you have left after drawing dots and text. If the SCART socket is wired the way most of these combos were, there might be RGB pins sitting there unused, and driving those is far more forgiving than building a colour signal from scratch. I never got that far with mine because the set died in the middle of the experiment, probly the capacitors, and I lost patience with recapping a telly that cost me nothing. One thing that helped me with the data side was letting the wifi board do more of the work. Mine pre-sorts the aircraft by distance and only sends the closest handful, which keeps the drawing loop short enought that I could squeeze the frame update into the blanking interval without the buffer ever backing up. With your ten second refresh that probably is not a problem yet, but if you widen the range later it might be.
Not sure I agree with the idea that RGB through the SCART socket would be the easy way. On an Uno you don't have the pins or the memory to push three separate channels and keep them timed togehter, whereas the composite luma path you've allready got working just needs a colour burst bolted on top. I tried the RGB route on a similar setup and spent more time chasing sync issues across three lines than I ever did fighting tint. If it were me I'd stay on the yellow input and accept whatever colour you can squeeze out of it, even if it looks a bit rough.
The buffering between frames is what saved mine too. I had a similar setup drawing tide times on a portable off a boat, and before I queued the updates the numbers would smear halfway across the screen whenever fresh data landed. One thing with the TV/VCR combo, mine would only show the external input thru the VCR's aux channel, so check that if the picture seems to vanish, the combo might be routing everything through the tape side first. Also the chunky text grew on me once I stopped trying to sharpen it, small tubes just have thier own look.
Total beginner here so sorry if this is obvious, but how does the wifi side of yours work? I've got an Uno doing nothing in a drawer and an old portable in the loft, and I'd love to put the local bus times on it for my lad before school. I keep stalling at the bit where the data actually arrives, no idea wether the little board talks to the Arduino over its own pins or if it's all one thing. Yours sounds like the closest example I've found to what I'm picturing. Also good to know 20km range is enough, I assumed you'd need the whole sky mapped.
Update: got the SCART lead wired up and the picture comes through, so that part works. But it's still black and white, no colour at all. One reply said RGB is too much for an Uno and suggested keeping composite and just adding the colour signal on top, wich sounds smarter but I've no idea where to even start with that. Anyone got a simple example I could crib from?
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