chris442
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1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 1:45 am

Hello all,

I am working on a project and I want to buy the right things before I start so I have a few questions.

I have a Raspberry Pi 4 and I want to have two Camera's displaying on their own display using only 1 raspberry pi. Is this even possible?

This is my first question.

I am a newbie on raspberry pi and researched but couldn't find the answer or do not know what to research.

Thanks
-Chris

pcmanbob
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 1:34 pm

Hi.

You can only connect one raspberry pi Camera Module and one Raspberry Pi Touch Display to the pi4 as each port for the camera and display only supports connecting one device.

would have thought this was obvious as you can only plug one cable in to each socket ....... ;)
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

alphanumeric
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 1:41 pm

The Compute module will do dual CSI cameras and dual DSI displays. With the correct daughter board attached.

Daniel Gessel
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 3:30 pm

Only one camera module connector, but multiple USB cameras are possible if USB might be a workable alternative. Some experiments were reported in the following thread:

https://www.raspberrypi.org/forums/view ... 3&t=261135

chris442
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 4:17 pm

https://www.arducam.com/dual-camera-hat ... raspberry/

What about this?

Can I have image from camera on on hdmi1 and image from other camera on hdmi2?

Daniel Gessel
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Location: Boston area, MA, US
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 4:41 pm

chris442 wrote:
Sat Jan 11, 2020 4:17 pm
https://www.arducam.com/dual-camera-hat ... raspberry/

What about this?

Can I have image from camera on on hdmi1 and image from other camera on hdmi2?
Don’t really know the product, but it seems you get the pair side by-side as a single camera image on the Pi -or maybe alternate video frames?

As far as showing the two images on different HDMI displays, you can certainly do that if you’re willing to write some code, but I can’t guess at the frame rates/resolutions you could achieve. Somebody with more experience can offer more help on the easiest way to get this to work.

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HermannSW
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 6:32 pm

chris442 wrote:
Sat Jan 11, 2020 4:17 pm
https://www.arducam.com/dual-camera-hat ... raspberry/

What about this?

Can I have image from camera on on hdmi1 and image from other camera on hdmi2?
I got (free) samples of the Stereo hat from Lee at Arducam.

Yes, you will get 1 image consisting of left and right camera images.
In case the cameras are both Raspberry v1 or v2 cameras, you get the exact resolution determined by the mode.
That means that each camera contributes only "width/2 × height" to the "width × height" frame for modes 1-7.
Reason is that Raspberry Pi has no idea that there are two cameras, it knows only of one.
These cameras allow to use raspivid and raspistill with Stereo camera hat:
https://www.raspberrypi.org/documentati ... /README.md

In case the cameras are Arducam models (0.3/1/2MP monochrome global shutter or 13/16/18MP color rolling shutter cameras) the result will be "2*width × height" frames. In software you can split the frame in left and half side and display on two monitors. You can connect DPI/DSI, HDMO0, HDMI1 and composite to Pi4B. What I heard was that only two of the 4 monitors can work at a given time.

"raspivid" allows to specify "--dispnum X" and decide on which display the preview window should appear (not shipped yet, if really needed can be made available with rpi-update).

Here is sample of (picamera) camera previews of one v2 camera on two displays (DPI and HDMI0):
https://www.raspberrypi.org/forums/view ... 7#p1582997
Image



Here is example Arducam monochrome global shutter cameras with Stereo hat.
2*1280 × 800 = 2560 × 800 frame:
https://www.raspberrypi.org/forums/view ... 2#p1569676
Image
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

chris442
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Sat Jan 11, 2020 7:58 pm

@HermannSW, thank you for this information it is really helpful. My guess now is that I will run two raspi, on their own camera and own display so I can get 1080 at the fastest frame rates. USB camera was a bit too slow.

Pytha
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Joined: Tue Jan 21, 2020 2:23 pm

Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Tue Feb 25, 2020 2:15 am

There is a stereo cable for 2 cameras available, ~ 13€ from China.
How to select between camera1 and camera2 ?

https://de.aliexpress.com/wholesale?Sea ... 0122031156

Image

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HermannSW
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Tue Feb 25, 2020 8:45 am

> How to select between camera1 and camera2 ?
>
Follow the Waveshare product documentation:
https://www.waveshare.com/wiki/Camera_Scheduler

The difference to Arducam stereo hat is that this stereo cable is NOT able to take images at the same time.
You can switch between both cameras, and then take a photo.

You have to solder a cable to the pad and use GPIO pin to select which camera is active:
Image
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

Pytha
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Tue Feb 25, 2020 11:37 am

Thank you, that's it :-)

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HermannSW
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Tue Feb 25, 2020 4:14 pm

The camera scheduler is expensive compared to the simple solution of adding a Pi Zero to your Pi to drive the other camera (5$ plus 5$ shipping). Regardless I did order one for 14.44$ with free shipping today, just for being able to play with, estimated delivery to Germany in a month from now.
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

Pytha
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Joined: Tue Jan 21, 2020 2:23 pm

Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Wed Feb 26, 2020 1:10 am

Experimentaltrieb :) - Natürlich habe ich VIER PiZero, einfachste Lösung ist
PiZero+Kamera + PiZero+Kamera (unter 20€) ... mit "Wechselobjektiven"

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HermannSW
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Re: 1 RASPI 4, 2 CSI Camera, 2 Displays, Possible?

Thu Mar 12, 2020 7:11 pm

Camera scheduler arrived, "Analysis of new (2-)camera scheduler" thread revealed that switching time is 0.5s:
viewtopic.php?f=43&t=267761
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

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