ESP8266 Analog Broadcast Television Interface

https://github.com/cnlohr/channel3

by _Microft • 2 years ago

132 23 2 years ago

github.com

mkesper• 2 years ago

Seems to be from 2020 (on ESP8266), PAL support added last year.

iosjunkie• 2 years ago

2016, actually. I remember watching his video on it back then: https://www.youtube.com/watch?v=SSiRkpgwVKY

dylan604• 2 years ago

How old of a TV do you need to still have an analog receiver?

saltymug76• 2 years ago

Most TVs with a tuner can still listen to analog signals, I'm assuming for legacy device support (game consoles, VCRs, etc.)

epcoa• 2 years ago

Not old at all. Almost every TV sold in the US with an ATSC receiver (so most mid to high end) will also do NTSC (and "clear"/unencrypted QAM-64/256 for cable) In the past decade it became more common for low cost TVs to drop the tuner entirely. These use jellybean tuner/demod parts and you tend to get the whole batch or nothing at all, once you have RF in, demodding NTSC is basically free.

codezero• 2 years ago

My mom kept around her old two in one TV with a VCR because she didn’t feel like digitizing a bunch of old VHS tapes. Glad she did because it’s fun to play the Nintendo and use a C64 on it :)

anthk• 2 years ago

Every one of them must and should have a coaxial cable input.

MeteorMarc• 2 years ago

Amazing!

Aissen• 2 years ago

Someone else recently using the code to test second-hand TVs: https://social.afront.org/@MLE_online/113235301898075851

_Microft• 2 years ago

That’s actually how I discovered the project.

russellbeattie2• 2 years ago

It should be mentioned that those radio frequencies (60-66 Mhz for Channel 3) aren't for unlicensed use like WiFi. I'm sure no one will really care especially at low power, but getting a call from the FCC (or worse a visit from the FBI) would sorta suck.

Edit: Oh, nevermind. This is meant to be connected by a cable.

whizzter• 2 years ago

Shouldn't be an issue since the page mentions connecting the TV (ie via cable) so nothing is meant to be transmitted in the air, rather just as an input to the TV.

Same way as old NES consoles or C64 computers sent their signal to TV's before composite, SCART and later HDMI became the way to connect. This was often via a pass-through antenna connector that was placed between the regular antenna and TV-set (so you didn't have to disconnect it) and then just tuned one of the TV channels to the channel the console used (and iirc that channel was often channel 3 as mentioned in the github page).

The top stackexchange answer is quite informative, https://retrocomputing.stackexchange.com/questions/14280/why...

russellbeattie2• 2 years ago

Oh, I misunderstood the first line: "Hook an antenna up to GPIO3/RX". I didn't realize it was talking about the television antenna.

As an 80s kid, I'm quite familiar with the adapter for Channel 3. This is a cool project if you've got an old TV. There was a post about Radio Shack catalogs the other day and I still lust over a portable 2" color television from 1989, which would be useless today. I almost want to find one on eBay just to try this out.

londons_explore• 2 years ago

The video in the top post here shows the antenna clearly transmitting over the air, not over a cable.

andrewstuart2• 2 years ago

People often freak out about these transmissions being against the law, but at least in the USA there are clear legal exemptions for hobbyist/experimental low power transmissions.

So don't worry about the sky falling, using this stuff is OK as long as you don't amplify it and it's in your interests to shield it if you can and just run it for brief periods of time - essentially, hobbyist/experimental usage.

tocs3• 2 years ago

Reference? I am not doubting just curious. Maybe a Wikipedia article or something.

solarkraft• 2 years ago

Side note about cnlohr: This man has done a lot of cool stuff. Initially discovered him through a 100W flashlight build, which is probably his most boring project. Over the years I’ve followed ColorChord, ESP8266 drones, WiFi strength mapping, big HTC Vive setups … there’s so much cool stuff to uncover.

ThrowawayTestr• 2 years ago

You can buy an ESP for literal pocket change. Insane that you can build a whole TV station for less than a cup of coffee.

tn1• 2 years ago

I guess you could say this is the modern version of the TV Typewriter: https://www.tinaja.com/ebooks/tvtcb.pdf

XorNot• 2 years ago

This is the most ludicrous, greatest thing I have seen in a while.

drzaiusx11• 2 years ago

Since this implements a framebuffer with basic color support I wonder if there's enough cycles (and interrupts) left to read a composite input signal to feed the buffer and make a little "broadcast from anything" box.

andrewstuart2• 2 years ago

https://github.com/rossumur/espflix

Along similar lines very impressive

kamranjon• 2 years ago

Reminds me of when Fabrice Bellard figured out how to broadcast digital tv signals using VGA cards: https://bellard.org/dvbt/

ESP8266 Analog Broadcast Television Interface

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