Slashdot Mirror

← Back to Stories (view on slashdot.org)

Microcasting Color TV By Abusing a Wi-Fi Chip (hackaday.com)

Posted by timothy on from the why-does-the-chip-keep-coming-back? dept.

szczys writes: The NTSC standard has effectively been replaced by newer digital standards, but most televisions still work with these signals. This can be done through a composite video connection, but more fun is to broadcast video directly to your television's analog tuner. This is what cnlohr has been working on, using a lowly ESP8266 module to generate and transmit the color TV signal. This board is a $3 Wi-Fi module. But the chip itself has a number of other powerful peripheral features, including I2S and DMA. This hardware makes it possible to push the TV broadcast out using hardware, taking up only about 10% of processor time. Even more impressive, cnlohr didn't want to recompile and flash (which is a relatively slow process) during prototyping so he used a web worker to implement browser-based development through the chip's Wi-Fi connection. Speaking of chip-abuse in the interest of hyperlocal signal propagation, reader fulldecent writes to point out a project on GitHub that "allows transmission of radio signals from a computer that is otherwise air gapped. Right now this could be useful for playing a quick tune or for pranks. But there are more nefarious uses as this could also be used to exfiltrate information from secure networks."

2 of 63 comments (clear)

  1. Outstanding! by CaptainLard · · Score: 5, Insightful

    This is the coolest little hack I've seen on /. since...probably dice bought it. More of this please!

    One minor quibble, no need to editorialize the "POTENTIAL SECURITY VULNERABILITY". We already know everything is a weapon for terrorists these days. How about instead of "speaking of chip abuse" we have "speaking of $3 computers with tons of hidden functionality"?

    1. Re:Outstanding! by Obfuscant · · Score: 5, Informative

      your car's starter motor violates FCC rules when the brushes get old, so you too will join the others in the gulag for violating the rules

      The phrase "intentional radiator" has a significance here. Google it if you are confused.

      It would be a good question to research if this intentional radiator met the limits of a Part 15 device, like the unlicensed AM and FM broadcast transmitters that you can buy or build.