tvjon
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Longer DSI ribbon

Wed Sep 16, 2015 9:53 am

As I'm eperimenting with various configurations, I wanted to have the RPi board separate from the display mounting.

This could also be useful for those needing to use a more elderly RPi which doesn't have the requisite mounting holes.

So a test with one of my camera board extended ribbon cables works fine as seen in attached pic'.

It also means that a lower profile case could be used or made, with RPi board by the side of the display module rather than on top of it.

Additionally, there's then no need for the stand-offs; just screws to hold the module, thus allowing a lower profile case.
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gadgetoid
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Re: Longer DSI ribbon

Wed Sep 16, 2015 10:37 am

I'll raise you 1.5 meters!

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plugwash
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Re: Longer DSI ribbon

Wed Sep 16, 2015 10:43 am

Of course working and being EMC compliant are two different things.

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alexeames
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Re: Longer DSI ribbon

Wed Sep 16, 2015 10:45 am

Phil did you try one of those Japanese HDMI camera extenders? (Looks like it)

Nice :lol:
Alex Eames RasPi.TV, RasP.iO

gadgetoid
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Re: Longer DSI ribbon

Wed Sep 16, 2015 11:32 am

I did. Of course the beauty of trashing any EMC compliance ( this HDMI cable is almost as thick as my arm, I suspect it'll be okay! ) is that I can now broadcast my Pi screen to every LCD in the building!

gsh
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Re: Longer DSI ribbon

Wed Sep 16, 2015 12:22 pm

Actually it'll almost definitely be compliant anyway, all the noise came from off the board rather than down the ribbon cable, although the signals are running at 700MBits they are only 200mV differential. But you're right I would never sell the device in that configuration for that reason...

Gordon
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Gordon Hollingworth PhD
Raspberry Pi - Director of Software Engineering

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BAStumm
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Re: Longer DSI ribbon

Fri Sep 25, 2015 6:46 pm

What is the maximum length that the DSI ribbon cable can be?

For my application, I would like to mount the RPi about 5 - 10 feet away from the touchscreen.

Aramas
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Re: Longer DSI ribbon

Mon Oct 12, 2015 2:51 pm

I bought a 1 metter dsi ribbon and it works, but sometimes the screen freeze.
This is the reason why ?

NB : it sometimes freeze with the stock ribbon too, but it look likes that there is a lot of more freeze with the 1 meter ribbon...

When I was with the stock ribbon I thought the freeze where coming from my configuration of raspbian, but if it's coming from the ribbon, there is a real problem, no ?

il_diavolo
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Re: Longer DSI ribbon

Mon Oct 12, 2015 7:59 pm

As I mentioned in another thread, it works with my 2 metre flat cable. However, it does seem sensitive to too many loops in the cable, for instance wrapping part of the cable around a cardboard cylinder (no prizes for guessing the provenance) to keep it tidy definitely will give some problems. I assume that there could be some cross talk between the tracks if several loops are in close proximity.

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