Raspberry Pi Forums

Hi,

I was thinking about methods I could use to allow multiple cameras with a single raspberry pi.

For my project I don't need both cameras functioning at the same time.

Therefore, surely it would be possible to have two camera ribbons feeding a switch which then goes to the Pi board. The switch would allow me to do an instant swap to another camera.

Would something like this be possible - given I could find a switch with (at least) two sets of 15 I/O (+ an additional 15 ports for the Pi board)? Or would the board notice the swap and stop transmitting?

Thanks

If you need any further info please let me know. I could knock up a quick system diagram to help explain.

http://hackaday.io/project/2847-ivport- ... ultiplexer

They've got four cameras on one RPi.

DougieLawson wrote:http://hackaday.io/project/2847-ivport- ... ultiplexer

They've got four cameras on one RPi.

This is interesting. The circuitry seems a bit more elaborate than I had expected and what seems necessary.

A further question: One of the two cameras I want to use will be a nightvision one - will this be a problem?

All cameras have the same electronics. The daylight vs NoIR is simply whether it includes an IR filter or not.

DougieLawson wrote:All cameras have the same electronics. The daylight vs NoIR is simply whether it includes an IR filter or not.

That's what I expected.

Do you have any idea where I could get a 2-way camera switch?

If you're into electronics, I doubt it would be too difficult to make a 2-way camera switch using a bank of switching transistors controlled by a single GPIO signal. That's assuming there are no additional protocol/driver or hotswap issues (I haven't done camera stuff yet on my Pi).

Snugglasaurus wrote:

DougieLawson wrote:All cameras have the same electronics. The daylight vs NoIR is simply whether it includes an IR filter or not.

That's what I expected.

Do you have any idea where I could get a 2-way camera switch?

Sorry I have no desire to run more than one camera per RPi.

Ask the folk who did that hackaday article.

mott555 wrote:If you're into electronics, I doubt it would be too difficult to make a 2-way camera switch using a bank of switching transistors controlled by a single GPIO signal. That's assuming there are no additional protocol/driver or hotswap issues (I haven't done camera stuff yet on my Pi).

Brave man to try it. The CSI-2 bus is 3 channels (2 data, 1 clock) each running at pushing 1GHz, and LVDS so needs appropriate transceivers.
Yes it is possible to do that, but it is not a simple task. That's why the 4 to 1 multiplexer people keep on pointing to costs $85.
You also need to mux the I2C and GPIOs between the devices for the control side - that bit is pretty trivial.

Plus the software doesn't intentionally support hot swapping. They are getting lucky as there is code in the GPU firmware that resets the camera if it stops receiving data on the CSI bus. On their mux switching, that is triggering and the new sensor picks up.

Or use a Compute Module as that does bring out both CSI-2 interfaces that are present on both BCM2835 and BCM2836.

Interesting, I stand corrected. That's what happens when I make unwarranted assumptions

6by9 wrote:

mott555 wrote:If you're into electronics, I doubt it would be too difficult to make a 2-way camera switch using a bank of switching transistors controlled by a single GPIO signal. That's assuming there are no additional protocol/driver or hotswap issues (I haven't done camera stuff yet on my Pi).

Brave man to try it. The CSI-2 bus is 3 channels (2 data, 1 clock) each running at pushing 1GHz, and LVDS so needs appropriate transceivers.
Yes it is possible to do that, but it is not a simple task. That's why the 4 to 1 multiplexer people keep on pointing to costs $85.
You also need to mux the I2C and GPIOs between the devices for the control side - that bit is pretty trivial.

Plus the software doesn't intentionally support hot swapping. They are getting lucky as there is code in the GPU firmware that resets the camera if it stops receiving data on the CSI bus. On their mux switching, that is triggering and the new sensor picks up.

Or use a Compute Module as that does bring out both CSI-2 interfaces that are present on both BCM2835 and BCM2836.

Thanks for your response. This was what I was worried about. I doubt this feature will be the easiest route to take for my project.

I think, instead, I will use 2 Rpi's (1 for each camera) and a simple hdmi switch leading to a single display.

Thank you for your help everyone!

Hi, maybe you are looking for this:
http://www.arducam.com/multi-camera-ada ... ulticam-6/