Hi everyone. I’ve got an Arducam B016601 Stereo Camera HAT on a Raspberry Pi Zero W. Camera A works and shows video fine, but Camera B just stays on a black screen and eventually times out with ‘Unicam has timed out!’ in the logs. I already tried different cameras and swapped the connectors around, same result. Anybody seen this before?
Thanks for the details. Which script or guide are you using to set up the adapter? The ‘Unicam has timed out!’ message usually means the unicam driver isn’t getting frames from that channel, so it’d help to know exactly how you’re configuring the mux.
I’m using the pi_cam_uc444.sh script from the Multi_Camera_Adapter repo: RaspberryPi/Multi_Camera_Adapter/Multi_Adapter_Board_2Channel_uc444/shell/pi_cam_uc444.sh at master · ArduCAM/RaspberryPi · GitHub
One thing I changed in it - the original had i2cset -y 1 0x70 0x00 0x01 and I changed it to i2cset -y 10 0x70 0x00 0x01. The only thing I see in the logs is ‘Unicam has timed out!’
That’s the problem. The Multi_Camera_Adapter repository you linked is deprecated and no longer supported - Arducam moved to a new way to drive the multi camera adapter. Please use the current documentation instead: Quick Start Guide for Multi-Camera Adapter Board - Arducam Wiki
Follow that guide to configure the Pi and enable the cameras, and the old script won’t be needed.
Okay, I did a fresh install of the Raspberry Pi OS image and followed the new guide, but now libcamera says ‘no cameras available’ when I run --list-cameras. Do I need to enable the I2C interface or is there something else I’m missing?
On a fresh install, check your /boot/config.txt for any leftover dtoverlay lines first. If an old overlay from a previous setup is still there, it can interfere with the new configuration. Also make sure the I2C interface is enabled for the adapter board.
Found it! There was a previous dtoverlay still sitting in the config. Once I removed it, the cameras showed up.
Spoke too soon. The cameras were detected, but now they’re gone again. Detection seems intermittent.
When they disappear, is it after a reboot or after a cold start? Also, can you double check that the dtoverlay you removed didn’t come back and that I2C is still enabled?
It happens after a cold start. If I remove the power cable, I always have to reboot once before the cameras are detected. That’s not practical for me since I don’t want to log into the Pi every time power is restored.
To summarize where we are: the leftover/previous dtoverlay in the config was confirmed as the main cause of the camera detection issues. If --list-cameras reports no cameras available on a fresh install, verify the existing dtoverlay and I2C interface configuration first. The intermittent detection after removing power still needs investigation, but the first thing to re-check on each cold boot is that config.txt is clean and I2C is enabled.