Nice Project!

First time I see your project, and like it too much!

I think HDMI and DSI will be quite tough to make it work with this technique. Do you plan to enhance it?

HDMI most definitely impossible yes. DSI doesnt operate at such high speed, so I was hoping I could maybe get atleast something going even if its very flaky. So far I was even unable to get DSI working with the official dev board. Will have to investigate that.

I don't plan on making this a neat breakout. Its a playground to test out stuff for other projects. I may make a different version that breaks out different features but all thats left to try apart from HDMI and CSI (camera) is Audio and Analog Video out. The latter should be both doable.

Thank you for your comments. 

What is your opinions about 2 layer pcb? Even if it is silk printed, is it possible to make differential pairs working properly?

@mbt28 I'm really no expert on this topic but the differential pairs for USB and DSI on this board are calculated as micro strips (https://www.eeweb.com/toolbox/edge-coupled-stripline-impedance).  The board is technically a 2 layer board, I just use the bottom layer as a GND plane without any traces. This should in theory enable differential pairs, but I'm lacking the capability that a PCB manufacturer has to do real impedance control which is fairly complicated and dependent on the stack-up of the board and the materials used. So yes a 2 layer board, if manufactured with impedance control, should work fine. Personally I have never done it and I often read that its recommended to work with 4 Layer boards so you can have a dedicated GND plane on more crowded circuits like you would likely have with a fully featured CM breakout.

I tried this is also without a GND plane on the bottom, at least USB worked the same, I dont know enough about the physics involved to know when the GND plane actually comes into play.