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jbeale
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Adapt RPi camera to round cable (not flat flex) ?

Tue Sep 17, 2013 7:18 pm

I may get to use the R-Pi CSI camera in a project at work. Due to size requirements I need the camera separate from the RPi itself. One question mark right now is the flat ribbon cable; it would be better to have a more manageable round cable.

Looking at the schematics I see the S5 connector on the Rpi going to the camera carries 3 high-speed differential pairs separated by ground lines, plus four low-speed signals (note: "CAM_CLK" is actually DC; the indicator LED), plus 3V3 power taking up 15 conductors in total.

Compare that to an HDMI connector with 19 pins, including 4 high-speed shielded differential pairs. You can get HDMI cables with 30-AWG wiring that are not too thick, and not too expensive (or even 3.5mm cable, for a crazy price). You can probably see where I'm going with this. You could put the camera signals through HDMI wiring with 4 conductors left over, for any other signal needs.

So I am considering making a set of R-Pi CSI connector flex to HDMI cable adaptor boards. If it works with 4 meters of plain ribbon cable, I suppose it works with HDMI cable qualified to 3.4 Gbps per channel.

My question: this seems reasonable enough that someone may have already done it? Or knows some reason why it wouldn't work? (apart from maybe some legal or trademark issue if the HDMI association hears about it).

tvjon
Posts: 706
Joined: Mon Jan 07, 2013 9:11 am

Re: Adapt RPi camera to round cable (not flat flex) ?

Wed Sep 18, 2013 8:54 am

Excellent idea!

You could also supply the 3v3 at the camera end if ncecessary.

It might actually be easier to test the using a DVI cable initially as the DVI socket might be easier to obtain & manipulate? In fact a cheap DVI to hdmi adapter could be used.

Be very interesting to see how you get on with your CSI adapters.

Here's a breakout that may be adaptable?

http://www.seeedstudio.com/depot/lcd-ex ... p-200.html

Also connectors:

http://www.digikey.com/us/en/ph/FCI/ffc_fpc.html

https://forum.sparkfun.com/viewtopic.php?f=14&t=27678

BTW, I realised a while ago that it was your very helpful pages I visited when I bought my TRV900E, so I'll take this opportunity to say thank you for that information.

Johnny5C
Posts: 82
Joined: Thu Apr 18, 2013 3:32 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Sep 19, 2013 11:56 am

Great idea.

RPI<CSI to HDMI<-- HDMI Cable-->HDMI to CSI>CAM

Keep us updated and good luck!

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rkinch
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Location: Palm Beach County, Florida USA
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Re: Adapt RPi camera to round cable (not flat flex) ?

Mon Sep 23, 2013 6:20 pm

Splendid idea. Definite need for a round cable with connectors.

May I suggest using the Type C or Type D miniature HDMI connections, rather than the full-size Type A?


ChristophA
Posts: 9
Joined: Sat May 04, 2013 12:07 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Wed Sep 25, 2013 3:23 pm

I have 2 of the "AlienSpec CSI DSI Ribbon Connector GPIO Breakout Board - for Raspberry Pi"
http://www.ebay.de/itm/AlienSpec-CSI-DS ... 1c2f3bca77
but haven't found the time to test some wirings between the breakout boards. That's still on my list...
LEDPi:
- Bitwizard SPI_RPi_UI
- Bitwizard SPI_3FETs Board
CameraPi:
- RPi Camara Module Rev. 1.3

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jbeale
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Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Sep 26, 2013 7:41 pm

As an update, the design at work has taken a turn in a different direction, so making the HDMI cable adaptor for the camera is on the back burner now. If anyone else is interested I think it's a pretty simple board layout, and pretty much anyone could do it.

Meanwhile I did just receive the flex cable extender kit from Bitwizard, and I can confirm the R-Pi camera works with their adaptor boards plus a 4-meter (13 foot) length of normal 16-strand ribbon cable (!) just as their post here said it would. This is really quite remarkable to me, given the CSI interface is designed for very short on-board runs entirely inside a mobile phone.

cabe
Posts: 24
Joined: Sun Jan 08, 2012 2:54 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Sep 26, 2013 10:25 pm

Interesting, it is incredibly simple to make those IDC cables round as well, as anyone who has hotrodded thier PC will know :) Especially as BitWizard provide the cables unterminated making adding the techflex nice and easy.

http://www.overclockersclub.com/guides/ ... ble_guide/

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AndrewS
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Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Sep 26, 2013 10:49 pm

jbeale wrote:Meanwhile I did just receive the flex cable extender kit from Bitwizard, and I can confirm the R-Pi camera works with their adaptor boards plus a 4-meter (13 foot) length of normal 16-strand ribbon cable (!) just as their post here said it would. This is really quite remarkable to me, given the CSI interface is designed for very short on-board runs entirely inside a mobile phone.
Awesome! :shock: Does it still work for video too? Did you have to decrease the framerate or resolution or anything? Any image degradation? This seems like one of those thing's that's just too good to be true :lol:

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jbeale
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Re: Adapt RPi camera to round cable (not flat flex) ?

Fri Sep 27, 2013 12:56 am

The ribbon cables I got from Bitwizard were actually terminated for me already. Actually 13 feet was way too long, so after testing at the original length I took one end apart and shortened the cable. At any rate the long cable did work both with stills and video at full resolution, no degradation that I could see.

Slicing up a ribbon cable to make it round may affect signal integrity. The high-speed signal lanes on the RPi camera cable are laid out in a specific order with a ground line between each pair. If you separate those to roll up the cable, you may end up with signal against signal for some part of the cable run, instead of signal against ground and that could affect things. But if someone wants to try it, it's probably not a big risk, cable is cheap.

cabe
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Joined: Sun Jan 08, 2012 2:54 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Fri Sep 27, 2013 8:35 am

Good point, those CSI signals are up to 208Mhz according to MIPI's CSI2 (I believe the RasPi is a CSI2, at least) interfaces. The fastest PATA133 ever went to was 70MHz (133MB/secs / 16bits) but CSI is a serial interface, so it *should* be more resilient than the old parallel interface.

I guess I need to put my money where my mouth is and order one up, shouldn't I :)

gazzat5
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Joined: Thu Jun 14, 2012 4:51 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Wed Feb 12, 2014 2:56 pm

Hi

Considering the interference issue, wouldn't it be possible to use the breakout from ebay (from link above) to convert to CAT5 ethernet cable?

In this case, the twisted pair could be used to maintain the original design of the ribbon: a signal cable paired with a ground cable.

Thoughts?

cbst
Posts: 6
Joined: Tue Jul 08, 2014 3:48 am

Re: Adapt RPi camera to round cable (not flat flex) ?

Tue Jul 08, 2014 4:49 am

I finally got around to building a couple of boards to convert the Raspi CSI Cam FPC to an HDMI-style connector. They work great, even with my longest cable (10m - shown below).
extender.JPG
extender.JPG (57.65 KiB) Viewed 21401 times
As an added bonus, the converter board tucks nicely into the widely available plastic camera shells.
extender2.JPG
Close up of board and board mounted with Raspi Cam.
extender2.JPG (47.59 KiB) Viewed 21401 times
I'm going to make up a few more boards for my use. I could probably build a few extras if anyone else is interested. Let me know via PM by July 20.

samsuh
Posts: 2
Joined: Tue Apr 15, 2014 8:33 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Jul 10, 2014 3:57 pm

Hi cbst,

This really an awesome work and possibility!

I would like to know if you have some trouble with the use of the video (FPS or resolution) ? And what about the total price of the modules?

I am really interested on something like this.

cbst
Posts: 6
Joined: Tue Jul 08, 2014 3:48 am

Re: Adapt RPi camera to round cable (not flat flex) ?

Fri Jul 11, 2014 1:40 am

samsuh wrote:Hi cbst,

This really an awesome work and possibility!

I would like to know if you have some trouble with the use of the video (FPS or resolution) ? And what about the total price of the modules?

I am really interested on something like this.
Thanks!

I haven't done extensive testing, but raspivid -o /dev/null -t 0 -fps 30 delivers a good video image with my 10m cable. If you have another command you would like me to try, let me know.

As I'm do everything by hand, at a very small volume, I'm charging $25 (includes postage within the USA) for a pair of assembled and tested boards and $10 for a pair of bare boards. PM me if you are interested.

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jbeale
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Re: Adapt RPi camera to round cable (not flat flex) ?

Sat Jul 12, 2014 3:10 am

Just FYI, I have a 2.5 foot HDMI cable from siliconmicrodisplay.com which is 2.6 mm in diameter, hopefully that will work. This should make it easier to have the camera board on a small servo-driven pan-tilt platform without being hampered the stiffness of the ribbon cable.

Note this is a standard passive cable. There are also super-thin longer HDMI cables that depend on an internal active amplifier, but I assume those would not work as the R-Pi camera signals are MIPI CSI2 and not in standard HDMI format.

bofre
Posts: 1
Joined: Fri Jul 18, 2014 11:39 am

Re: Adapt RPi camera to round cable (not flat flex) ?

Tue Jul 22, 2014 10:48 am

Hi cbst
Do you made some extensive tests with the cable?

harpss1ngh
Posts: 22
Joined: Mon Apr 21, 2014 10:03 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Mon Jul 28, 2014 8:01 am

Hi would you happen to have any more of these for sale?

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jbeale
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Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Aug 07, 2014 2:39 am

I just got a set of these flex<->HDMI connector boards and am happy to report that it works fine using the 2.5 foot "Ultra Thin HDMI Cable" from SiliconMicroDisplay.com which is only 2.6 mm in diameter. That makes it much easier to bend than a normal HDMI cable, and it makes the camera board easier to position without having to bend the wide stiff flex cable.

cbst
Posts: 6
Joined: Tue Jul 08, 2014 3:48 am

Re: Adapt RPi camera to round cable (not flat flex) ?

Wed Aug 13, 2014 3:51 am

jbeale wrote:I just got a set of these flex<->HDMI connector boards and am happy to report that it works fine using the 2.5 foot "Ultra Thin HDMI Cable" from SiliconMicroDisplay.com which is only 2.6 mm in diameter. That makes it much easier to bend than a normal HDMI cable, and it makes the camera board easier to position without having to bend the wide stiff flex cable.
Good to hear that they are working for you! I've got a couple of pairs left if anyone is interested. PM me.

MrJack
Posts: 3
Joined: Tue Sep 02, 2014 3:09 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Tue Sep 02, 2014 3:20 pm

csbt, do you still have any of these boards made up?

They look to be just the solution I need for my pi based doorbell.

I'd send you a pm, but it appears I'm too new a member!

ljcljc
Posts: 13
Joined: Wed Sep 10, 2014 6:43 am

Re: Adapt RPi camera to round cable (not flat flex) ?

Wed Sep 10, 2014 6:59 am

Hi, csbt

I am also interested in your board, cause I need it in my project to place the camera far away from Pi. I cannot PM you since I am newly registered. Could send me an email, so we can discuss it later?

my email: ljcljcljcljc@gmail.com

Thanks

codedborn
Posts: 1
Joined: Sat Sep 13, 2014 11:21 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Tue Sep 23, 2014 9:08 pm

Hi csbt,

The same situation here. I am newly registered and so not able to PM. I am interested in your board (convert to hdmi and back). Can you send me an email at codedborn@gmail.com? Thank you!
ljcljc wrote:Hi, csbt

I am also interested in your board, cause I need it in my project to place the camera far away from Pi. I cannot PM you since I am newly registered. Could send me an email, so we can discuss it later?

my email: ljcljcljcljc@gmail.com

Thanks

Project XXX
Posts: 15
Joined: Thu Oct 02, 2014 9:36 pm

Re: Adapt RPi camera to round cable (not flat flex) ?

Thu Oct 02, 2014 9:43 pm

Hi Csbt.

Pls. PM me 2 or mail: mikkel@mpentreprise.dk, cause i'm also really interesting in the converter boards, and how many have you left?

Regards
Project XXX

arditi
Posts: 2
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Re: Adapt RPi camera to round cable (not flat flex) ?

Wed Oct 15, 2014 5:23 pm

Hi cbst,

I too am interested. please email me at arditi (at) visibilitymetrics..

Thank you.

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