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I am looking for examples of connecting multiple camera modules to a single CAMIF for multi sensor still-image acquisition (ie, very low speed per sensor). The broadcom chip used in the raspberry pi supports up to 20 MP sensors. I want to connect 5 14MP sensors.

I assume since one of the signals is the vsync that indicates the end of a frame, an fpga could be used to properly mutiplex across the multiple modules (perhaps having to dump frames occasionally).

Does anyone have an example of someone doing this in the real world?

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  • \$\begingroup\$ have you solved this issue? If yes, could you please post in here the solution and the hardware used? I am specially curious about the 14MP sensors :D \$\endgroup\$ – mFeinstein Mar 14 '13 at 2:41
  • \$\begingroup\$ Are you talking specifically about RPi as a hardware platform? \$\endgroup\$ – Dmitry Grigoryev Apr 6 '16 at 10:15
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"CAMIF" = Camera Interface.

Thoughts only - I have no 1st hand experience of this.

If you can frame sync the sensors there should be no need to lose frames, changing sources during the frame sync signal.

The excessively enthused could add a hardware buffer to clock in frame data from the next source and then swap to that and load from it when current frame is finished. IF you can load fast enough to pull ahead before frame end you can then swap to real time and assign buffer to next in line. Two x RP sounds easier :-).

If you cannot frame sync then progressive startup of sensors so next in line is available soon after end of current may allow minimal loss. Below I show sensors starting 1.xx after the prior one but of course just staggering startups by say 0.1 of a frame time would mean that the next sensor is available soon after the current is finished. They will drift relative to each other - slowly so if under crystal control. Just resync when delay gets too long or short.

11111111 = frame 1 etc

111111112222222233333333444444445555555566666666...
.........111111112222222233333333444444445555555566666666...
...................11111111222222223333333344444444 .........

If sensors are fully asynchronous you could just look for next frame sync after end of current frame and switch to that. Order will (almost always) be non sequential but you should cover all in time.


Oh Wow!!! department:

Samsung's "multimedia" S3C6410X RISC Microprocessor offering.
1370 page datasheet :-)
I can't find it for sale :-(
424 pin FBGA - 13mm x 13mm

S3C6410X RISC Microprocessor

http://www.rasterman.com/files/man-6410-1.2.pdf

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