#apertus IRC Channel Logs

MEETING TIME, who is here?

Great, any news?

yes, there are some news worth sharing today

the background here is that we know that our HDMI is somewhat incomplete or maybe even incorrect and this causes some devices to behave a little weird

so we spend some thought on how to capture this data, which is typically high speed data (think Giga Hertz) in Current Mode Logic and thus cannot be simply captured with any logic analyzer

while doing so and testing some of those, I though to myself, it all would be way easier if we could slow down a 'known good' signal enough to easily capture it with reasonable quality

normally HDMI uses around 150MHz and can go down to 25MHz or so on 640x480 but that still means that the data is sent at 10 times the speed

now this is quite easy to capture with a logic analyzer that can handle arbitrary voltage levels, which my rigol mso fortunately does

so the next step was to reconstruct the actual 10bit data from the logic analyzer capture, further analyze and interpret the data and finally decode all the information making up the HDMI signal including the very important data islands

I've spent most of last week on getting all that done and having a proper test setup here and while I didn't manage to compare the signals yet, I managed to capture and interpret the 'known good' signal from the RPi

where the interesting parts are probably the PNG images of the decoded and interpreted frames and the TXT elaboration on the frame analysis

note that this will allow us to fine tune and tweak the HDMI output in a way that we can be pretty sure to generate compliant HDMI output in the near future

that's it from my side for today.

And the power adapter PCB delivery has also arrived?

Ah ok

Quick update from me: for ordering the power connector PCB still waiting for Oscars feedback about sending the payment

thanks for the moderation se6astian!