Hi everyone, I’m working on a project where I need to capture 4 pictures at exactly the same time using the 4-channel multi-camera adapter board v2.2. I also need the 4 images combined with no border between them. I followed the setup on GitHub and the demo works - all 4 cameras show an image. But I can’t figure out how to actually capture them simultaneously. Any ideas?
Welcome! Quick question before we dig in - when you say “at the same time”, do you need true simultaneous capture (all 4 shutters firing at the same instant), or would a very fast sequential capture be acceptable? The reason I ask is that the product page for the multi-camera adapter board v2.2 specifically states: “Cameras work in sequential, not simultaneously.”
Thanks for the reply. I need true simultaneous capture - the 4 frames need to line up at the same moment. The demo showed all 4 preview images at once, so I assumed simultaneous capture was possible. Maybe the preview just cycles through them? I also want the final output combined with no borders.
Right, the live preview showing all 4 cameras can be misleading - the demo just multiplexes the streams sequentially. With the adapter board v2.2 you can’t make four cameras work simultaneously; it’s a hardware limitation of that board, not a software setting. For genuine simultaneous multi-camera capture you’d need one of the Multi-Camera CamArray products instead. They’re listed here: Multi-Camera Solution - Arducam Wiki
That makes sense. I checked the CamArray page. Since I already own 4x Raspberry Pi Camera Module 3 (IMX708), can I just buy the adapter/HAT board on its own and reuse my existing cameras? Or do I need the full kit?
Good question. Unfortunately you can’t use your existing Camera Module 3 units with the CamArray HAT board as-is. Here’s the catch: the cameras that ship with the HAT board have had their clock signal cut to make them compatible with the board. A standard IMX708 module will still send its clock signal while running, and that clock signal conflicts with the HAT board. So your four standard Module 3 cameras would clash with it.
Ah, I see - so it’s a hardware modification on the camera modules themselves, not just a cable or config thing? Just to be sure I understand: the HAT expects cameras that don’t drive the clock line, but my Module 3s do, and that’s the conflict?
Exactly. The HAT-compatible cameras have the clock signal cut for compatibility. A standard IMX708 sends its clock signal, which conflicts with the HAT board. So there isn’t a config or software workaround I’m aware of - the existing modules aren’t compatible with the HAT board as-is. To sum up the whole thread: the adapter board v2.2 is sequential-only and can’t do simultaneous capture, and for simultaneous capture you’d need a CamArray product, but you’d need the HAT-compatible camera modules rather than your existing Module 3 units.