using HDMI cable extension for Mobius camera = extreme remote?

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#1
Hi, first post.
Nice guides on the dashcams you got here and a pretty helpful forum.

I had one of the (nowadays $50) dashcams some years back, but it killed itself while the car was sitting in the sun at 17 deg south of the equator. At least I got my $140 back after this happened and didn't bother to buy another one since then..

Fast forward and I find that the market has evolved, but still not satisfying.

Anyhow, I stumbled across this piece of tech today:
https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

I don't know if the Pi camera modules do boost the signal a bit (there is a couple of SMD capacitors and ICs on the back of it), but how big a chance is there that the mobius camera module could be placed 4-5 meters from the mobius housing this way (have to make my own adapter board, FPC <> HDMI), instead of the 20 cm that the longest extension cord offer currently?
 

jokiin

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#2
but how big a chance is there that the mobius camera module could be placed 4-5 meters from the mobius housing this way (have to make my own adapter board, FPC <> HDMI), instead of the 20 cm that the longest extension cord offer currently?
extremely slim chance I would say
 
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#3
Unless the interface employed between the MCU and the CMOS via that 26pin FPC is Parallel, this should be possible, no?
An HDMI+ETH cable (5 diff-pairs) should be able to transfer the digital data (4 MIPI/HiSPI lanes + clock).
What's left are controller signals and the power stuff (which should be provided from raw power at that adapter where the cable attaches to the CMOS, like they do for the RPi camera modules). In worst case maybe another USB 3.0 cable alongside for the control signals for the CMOS..

So the question really boils down to, what interface is used between the MCU and the CMOS over that 26 pin FPC.
Anyone knows?
Thanks!
 

jokiin

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#4
have seen it done over HDMI cable and over several metres distance, very unreliable and prone to issues, look at Innovv C3, Biker Pro for examples of this method in use
 

kamkar1

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#5
I think the actual television HDMI protocol and signals are able to work over pretty long HDMI cables, but it is not something i would rely on that's for sure.
I have no idea about what go on between the lens module and the main PCB of the mobius, but as it cam only handle the short 20 cm or so cable i would assume that what run thru that cable are pretty much what come off the sensor so some CSI-2 signal or something. ( not rally much into such matters )
 
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#6
Any similar cameras able to do this or did we find a way yet? I want a 4-6 channel setup with the brains in the glovebox.
 
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#7
You would be looking at 28AWG cables at a minimum, more likely 26 or 24. and before you say ah but micro/mini hdmi, look at the longest length cables (even as short as 12 feet!) on amazon: all negative reviews.

http://www.bluejeanscable.com/articles/how-long-can-hdmi-run.htm
http://www.bluejeanscable.com/store/hdmi-cables/hdmi-cable.htm

until this is offered as an off the shelf option from one of the dashcam manufacturers, it's not viable.

there's a separate standard entirely, HDBaseT, which was created specifically to address the HDMI length/scalability problem.
 
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