Hello, I was wondering if perhaps the 2 MIPI CSI ports on the Rock Pi 4 meant it could be used with 2 cameras? Is that possible or is the second port for something else? Thank you!
2 cameras on the Rock Pi 4
no. The DSI connector lacks some signal for camera if it’s configured as CSI.
USB cameras are a million times easier to deal with.
Right, but slower, and if you have two even more so.
Thank you for the help.
Slower? How do you figure?
By no means an expert, but I heard that the MIPI CSI interface provides a high-bandwidth connection to the GPU, which will result in higher frame rates for a MIPI camera than an identical USB counterpart. I need 2 cameras for binocular vision and depth mapping, so I’m particularly sensitive to low frame rates. Please correct me if this is wrong.
USB 3.x provides as high or higher bandwidth as CSI. In addition, many/most USB cameras will optionally implement varying forms of compression (often can be configured by you), which can significantly reduce the total amount of data required. For USB interface, you will also find a much greater selection of “ready to use” cameras and lenses than you will find for CSI, which tends to mean that you can choose much higher quality and better suited sensors/lenses for your application – this is especially obvious when you’re tied into the “raspberry pi” compatible ecosystem and get the choice of blurrycam or nightvision blurrycam.
Hmm. Downside of being a novice I guess. Also I think I read about this topic before the pi compatible boards had USB 3. Thanks!
Edit: I’m actually not finding any cheap USB 3.0 or USB 3.1 cameras. Most specialized products are well over my budget, and cost way more than any pi compatible board.
Try ELP cameras. This is their website: http://www.elpcctv.com/
However, note that they don’t seem to have a very relevant or up to date listing there.
You can usually find their cameras on Amazon or aliexpress or other retailers.
http://www.webcamerausb.com/usb30-camera-module-c-62/
Thanks! Tempted to try one of these. Do you have any experience using them, as far as quality goes?
Edit: sorry to keep heaping on the questions, but do you happen to know of any such usb cameras with hardware synchronization, e.g. an external trigger pin? I don’t see a datasheet for the ELP cameras, but they don’t appear to have a sync method.
Yes, quality on them is FAR greater than “pi” cameras. On the order of comparing a google pixel with an old flip phone from 2001. HOWEVER, they do offer cameras with a variety of sensors. I’ve used Sony, and I think it was Aptina?
Regarding synchronization, you may want to check with ELP for your requirements. I’ve seen that they have some dual sensor synchronized modules at USB2.0, but I haven’t used any, nor do I know if they have similar USB3.0.
This could be an option;
https://www.amazon.com/Fisheye-Camera-Module-Synchronization-1-3Megapxel/dp/B073F4Z9BW
Note that I’ve never used that brand, so can’t comment on it beyond the specifications.