When we start the rkaiq_3A_server, the video produced on /dev/video13
become monochrome. Automatic exposure is working well.

Is there a different /dev/video or /dev/media output for color frames?
Is there some configuration we are missing?

We have tested with the unmodified imx415 driver.

We do need the native 1920x1080 image format and have modified the imx415.c driver accordingly.
The system now streams HD video at 38fps.
The vertical_blanking control is set to its minimum value of 1154.

Like the poster of https://forums.luckfox.com/viewtopic.php?t=2577
we would like to get the ...

The IMX415 recommended for use with this board is limited to 19.4fps due to the processing limits of the RV1126B.

We do not need the sensor's full 4K resolution.
How does one configure the sensor for 2x2 binning to reduce its readout to HD
(1920x1080) resolution?

I've figured out how to slow the frame rate by increasing the vertical blanking interval with:

v4l2-ctl -d /dev/v4l-subdev4 --set-ctrl vertical_blanking=200 #any value >58
although the system responds with:
VIDIOC_SUBDEV_S_CLIENT_CAP: failed: Inappropriate ioctl for device
it still performs the ...

I followed the instructions in:
https://forums.luckfox.com/viewtopic.php?p=7829

to add hardware video encoding/decoding to the standard Debian Trixie image.

The test code pipeline:
gst-launch-1.0 videotestsrc num-buffers=600 ! video/x-raw,format=NV12,width=640,height=320,framerate=60/1 ...

Why can't this board boot from its SDcard?
Is it due to some hardware limitation, or simply a limitation in the supplied bootloader?

Note that I maintain Armbian for the RockPI-S and am considering porting it to this (very similar) board.
That would involve porting Armbian's U-Boot over to it ...

The published schematic uses the RK3308's LINEOUT_R pin to drive the on-board speaker amplifier.
Are the LINEOUT_* signals available anywhere else to drive an external stereo amp, for example?

I can get LINEOUT_R from C18, but where is LINEOUT_L?

Thank you!