Camera module 2

[phodina]

Hi @eclecticc ,

firstly thanks for the updated camera module!

Are they pin to pin compatible with the original camera module that you describe here? https://github.com/FrameworkComputer/Framework-Laptop-13/tree/main/Webcam

Since the OV08X camera sensor supports just MIPI interface how do you connect it to the AMD CPU? Or is there some co-processor along the way that does the Image processing DSP operations (3A algorithms)? Or just some MIPI to USB bridge that pushes the RAW image to AMD processor that then leverages GPU to process the image?

Also where can I get the datasheet for the sensor to get information about the registers and modes of operations?

What's the best way to modify the sensor registers over I2C? i2c-tools or libcamera (or something else)?

[amstan]

The connector to the webcam is compatible, yes. The only way to talk to the camera (indirectly) is through usb (that's the only interesting data pins going to the camera), so you're talking to a mipi to usb bridge. Based on those facts, at first glance, you're not likely to be able to get access to the sensor registers easily.

Here's an lsusb dump which should match what you would get (+- some firmware version differences):
webcam.lsusb.txt

[JohnAZoidberg]

Like @mstan said, the DSP uses the USB UVC protocol. No MIPI access from the host.
So you can use UVC driver and tools to acess the camera.

On Linux it's handled by the v4l2 kernel driver. You can use the v4l-utils to interact with the camera through USB.

Is there anything specific that you're interested in?

[phodina]

@JohnAZoidberg I work on products that run on embedded Linux and interface with cameras over MIPI and also use Framework 13 AMD laptop so I'm curious how you handle the image pipepline.

Also I got recently the new webcam module and would like to do some comparison on them.

Also I own Lenovo ThnikPad X13s Gen1 with Snapdragon SoC wehre the MIPI lines are directly attached to the processor. The only issue is that on Linux the IDSP does not work and the RAW image has to be processed by the CPU :-/

[phodina]

@JohnAZoidberg do you also use the RTS5803 MIPI to USB brigdge?

Do you have datasheet for the IC?

Also how do you calibrate the camera sensor and where do you store the calibration data?

[JohnAZoidberg]

We've got the DSP names on our marketplace.
https://frame.work/tw/en/products/webcam-module

RTS5879 for 2nd gen camera.
RTS5853 for original camera.

[JohnAZoidberg]

Since the modules are standalone and can be used on lots of different of our mainboards. Even across 13 and 16 inch, all tuning and calibration data is stored in the module.
Tuning is done together with the framework laptop bezels.

Sorry Realtek does not make the data sheets public right now.

[phodina]

Understood and thanks for the part reference and info on the calibration data.

[phodina]

Would it be possible to specify the max amount of current you support on the 3.3V rail?

Do you use the ambient sensor to adjust the camera or is that just for the screen brightness?

[JohnAZoidberg]

Would it be possible to specify the max amount of current you support on the 3.3V rail?

How much current the module would draw? I'm not sure. Why are you asking?

Do you use the ambient sensor to adjust the camera or is that just for the screen brightness?

Neither of those is done in firmware. Windows and Linux both adjust screen brightness based on ALS sensor readings.
Neither of them adjust anything related to the camera, as far as I'm aware.

[phodina]

How much current the module would draw? I'm not sure. Why are you asking?

Well, since I replaced my webcam module I have the old one which could be used in some project. So that would help to estimate the power supply.

[xorgy]

Like @mstan said, the DSP uses the USB UVC protocol. No MIPI access from the host. So you can use UVC driver and tools to acess the camera.

On Linux it's handled by the v4l2 kernel driver. You can use the v4l-utils to interact with the camera through USB.

Is there anything specific that you're interested in?

I got mine and it generally functions well, though there are some autodetection issues with some applications. For example, chromium based browsers seem not to see the 720p resolution option, so it'll fall back to VGA in Google Meet and similar.
I'm also curious if any framerates other than 30fps are supported by this chip, and if Framework has leeway to push firmware to advertise those over UVC. Particularly 24-based framerates are of interest to me.
Also one frustrating thing is that the v4l controls don't have an integrated ‘gain’ control like many UVC cameras (e.g. Logitech Brio), which makes pinning exposure a bit painful (because you have to play with contrast and brightness separately).

So in summary:

• investigate issues with how the camera is detected, which cause it to default to worst-case resolution in chromium on linux, and see whether this can be resolved with tweaks to how UVC modes are exposed.
• look into framerates other than 30 (if possible with these chips)
• look into exposing a single gain control (in addition to existing controls)

I am of course assuming here that Framework has the ability to make changes like these to the firmware, and that fwupd isn't wrong when it says the firmware is updatable. I assume this is the case since there is a customized privacy switch feature which is exposed through UVC.