chegde
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Maximum length of ethernet cable between Raspberry Pi and camera

Mon Sep 16, 2019 5:32 pm

Hello,

Due to some constraints I cannot use only a flex cable to connect the Raspberry Pi to the Raspberry Pi camera. The connection I can use is as follows:

Raspberry Pi --> Short flex cable --> RG6 cable --> Ethernet cable --> RG6 cable --> Short flex cable --> Pi camera

How long can the ethernet cable be in order to make sure that the signal sent by the camera to the Pi is still intact? From my understanding, the longer the cable is the greater the interference with other signals and also greater the attenuation and voltage drop. How do I know what is the maximum length of ethernet cable I can safely use?

Thanks

jamesh
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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Mon Sep 16, 2019 6:20 pm

Are you doing any sort of conversion/power amplification? If not then not very far, probably 1 or 2meters, but it will be very susceptible to interference.
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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Mon Sep 16, 2019 7:23 pm

I'm aware of an adaptor for RPi camera extension using HDMI cable, which I have used. I used a very thin and flexible type of HDMI cable (only a few mm in diameter, and less than 1m long) and it worked. This version claims a 5 meter HDMI cable works: https://www.tindie.com/products/freto/p ... extension/

I'm not aware of any adaptor converting the standard RPi camera 15-conductor flex cable to RG6 (single-conductor coax). It seems like you'd need many coax pairs to handle all the different signals, which would be very bulky.

chegde
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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Mon Sep 16, 2019 8:04 pm

jbeale wrote:
Mon Sep 16, 2019 7:23 pm
I'm aware of an adaptor for RPi camera extension using HDMI cable, which I have used. I used a very thin and flexible type of HDMI cable (only a few mm in diameter, and less than 1m long) and it worked. This version claims a 5 meter HDMI cable works: https://www.tindie.com/products/freto/p ... extension/

I'm not aware of any adaptor converting the standard RPi camera 15-conductor flex cable to RG6 (single-conductor coax). It seems like you'd need many coax pairs to handle all the different signals, which would be very bulky.
Thank you. Did you have any problems with interference? The link you shared says that signal quality was not affected but I will have multiple sensors and RPi's in this setting. I was wondering if this setup would still work in this kind of an environment.

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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Mon Sep 16, 2019 8:33 pm

We cannot guarantee anything more than the length of the cable supplied with the camera. The onus will be on you to test it in your environment. I was very surprised when that long cable was claimed to work....
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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Mon Sep 16, 2019 9:55 pm

chegde wrote:
Mon Sep 16, 2019 5:32 pm
Hello,

Due to some constraints I cannot use only a flex cable to connect the Raspberry Pi to the Raspberry Pi camera. The connection I can use is as follows:

Raspberry Pi --> Short flex cable --> RG6 cable --> Ethernet cable --> RG6 cable --> Short flex cable --> Pi camera

How long can the ethernet cable be in order to make sure that the signal sent by the camera to the Pi is still intact? From my understanding, the longer the cable is the greater the interference with other signals and also greater the attenuation and voltage drop. How do I know what is the maximum length of ethernet cable I can safely use?

Thanks


What, specifically, is this 'Ethernet' cable you plan to use?

I have installed a number of Ethernet Local Area Networks and I can think of at least 8 different cabling standards that I might have used at one time or another.


Realistically, I think you are so far beyond the design limits of the camera module and its associated cabling that your own experience will be the only useful guide.

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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Tue Sep 17, 2019 12:11 am

As Jamesh stated and 6by9 always does as well, there are no guarantees for anything longer than 15cm flex cables due to possible signal issues. But I use 1m and 2m long flex cables for years now in addition to the 15cm ones without issues. I also have flex cable extenders that allow to connect flex cables, and tested 3m long flex cable as connection of 1m and 2m cable without issues. The default cable length I use regularly is 1m. I learned that I need to make sure flex cable does not come too close to mains cables (of the led drivers on right middle of photo).

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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Tue Sep 17, 2019 12:42 am

In my use case with a thin HDMI cable, there was no interference, but then it was outdoors with no other signal sources anywhere around. If you have other cables or signal sources immediately adjacent, then I would expect some effects. Other things being equal, I would expect an HDMI cable to be less susceptible to interference than the same length of flat flex cable just by the conductor geometry. As others have stated, this is well outside the intended design for the very high bandwidth camera data bus, and you would have to try and see what happens in your particular setup.

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Re: Maximum length of ethernet cable between Raspberry Pi and camera

Tue Sep 17, 2019 9:52 am

chegde wrote:
Mon Sep 16, 2019 5:32 pm
Hello,

Due to some constraints I cannot use only a flex cable to connect the Raspberry Pi to the Raspberry Pi camera. The connection I can use is as follows:

Raspberry Pi --> Short flex cable --> RG6 cable --> Ethernet cable --> RG6 cable --> Short flex cable --> Pi camera

How long can the ethernet cable be in order to make sure that the signal sent by the camera to the Pi is still intact? From my understanding, the longer the cable is the greater the interference with other signals and also greater the attenuation and voltage drop. How do I know what is the maximum length of ethernet cable I can safely use?

Thanks
Why not use an Ethernet enabled camera instead then ? With the Pi4's high speed Ethernet and a decent hub you should be able to run a huge network of cameras over long distances.

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