Hey all, hitting a strange timeout issue with my Arducam Quad-Camera Stereo Synchronized Kit. I’ve got 4x IMX519 cameras, and whenever I hook up only 2 of the 4 I get a timeout error. If I connect 3 of the 4 cameras it works with no problem. Is there any way to run with just 2 IMX519 cameras connected? I’d prefer not to have to wire up all four if I can avoid it.
Hi, thanks for posting. To make sure I’m looking at the right setup: you’re using the Arducam Quad-Camera Stereo Synchronized Kit with 4 IMX519 units, correct? Could you share a screenshot of the timeout error and any logs from when it happens?
Yep, 4x IMX519 on the quad-camera stereo synchronized kit. Here’s the timeout error I’m seeing: 
Thanks, that’s really helpful. What you’re describing (2 of 4 = timeout, 3 of 4 = no problem) points to how the board handles the camera channels. The cameras need to be connected in specific channel pairs. You need at least one camera connected on RX0 & RX1, and at least one camera on RX2 & RX3. If your two cameras are both sitting on the same side/pair, the other channel pair never comes up and you get the timeout.
Ah I see, that would explain it — I had both cameras on the same side. So I can’t just use RX0/RX1 for both? How do I set up dual channel mode properly?
Right, both on the same pair won’t work for a two-camera setup. You’ve got two options. First, just connect one camera on RX0 & RX1 and the other on RX2 & RX3 — that satisfies the pairing requirement. Alternatively, if you connect all four cameras to the HAT board, you can enable dual channel mode with these i2cset commands:
Set to double channel (single channel 0 and single channel 1):
i2cset -y 6 0x24 0x24 0x01
Set to double channel (single channel 2 and single channel 3):
i2cset -y 6 0x24 0x24 0x11
Thanks for that. So just to confirm — the dual channel mode has to be enabled with those i2cset commands, and the cameras have to be arranged in the RX0/RX1 and RX2/RX3 pairs for two cameras to work?
Exactly. Dual channel mode needs to be enabled via the i2cset commands, and the camera connections must be arranged in the required channel pairs (RX0/RX1 and RX2/RX3) for the two-camera configuration to work. Try that arrangement and run the commands, and let us know if the timeout clears.