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plusvic / simplebus2-intercom

General description of the Simplebus2 protocol used by some Comelit's intercoms. Hardware for retransmitting Simplebus2 messages over UART.
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Audio/Video protocol #7

Open gizahNL opened 1 year ago

gizahNL commented 1 year ago

Do you have a description of the A/V protocol that is used on simplebus2? Would be really cool to hack together a device that can hook into the A/V stream & relay it onto my network.

plusvic commented 1 year ago

The A/V signal is analog, not digital. It looks like some kind of composite video, but I'm not sure whether it is PAL, NTSC or SECAM. My expertise in that area is close to null. I had the idea of decoding the A/V signal too, but after some investigation I concluded that my knowledge about analog electronics is too limited for such undertake. If anyone with more experience can make some progress on that it would be great.

plusvic commented 1 year ago

See #6.

issalig commented 11 months ago

I was able to see the image with just a cheap USB video capturer. You only need gnd and as far as i remember the composite signal is the yellow cable that goes to the screen.

plusvic commented 11 months ago

@issalig that's very interesting, can you share more details about your setup?

issalig commented 11 months ago

I have re-opened the intercom and yes, it is the yellow cable that goes to the CVBS in the pcb silkscreen upper left connector. I added a soldered yellow dupont cable to get the video signal (see image)

I did it two years ago and just checked video was readable with a usb capturer but I do not use it. The model is similar to this one https://es.aliexpress.com/item/1005004152893546.html and I just conected CBVS and GND to the yellow RCA connector on the usb dongle.

For the upper right connector in the pcb I would say that B+BB- are for brightness and C+CC- for contrast

image

morganflint commented 5 months ago

Hello, great project! I understand capturing and streaming the video with cheap devices like ESP32 might be nearly impossible but, what about just audio? It must be possible to do it directly from the simplebus2 signal, as the Ring device does (bilateral)... but maybe the associated hardware isn't simple

Elektroarzt commented 5 months ago

Hi ... for the basic communication part of the S2 bus except audio / video we have a solution, but audio would be very interesting. Here is a link to an issue of a spinoff project, where sashahilton00 documented his investigations concerning audio so far. Maybe it helps or is a start.