Hi everyone, hoping someone here has seen this before.
I’ve got a B0205 1080P Day & Night Vision USB camera module that’s been working perfectly for about a year on my Raspberry Pi 4B+. Out of nowhere the auto IR-Cut switch has stopped working.
Symptoms:
In night/dark conditions I just get a totally black image.
The day-night sensor (photoresistor) seems to work fine - the IR LEDs clearly turn on.
Normal daylight video is fine.
So the IR LEDs come on, but the image is black. I’m guessing the IR-Cut filter isn’t flipping out of the way for night mode, but I’m not 100% sure how to confirm that. Any ideas on what to check first?
Hi, thanks for the detailed description. A couple of quick questions before we dig in:
Could you capture a video showing the behaviour? Ideally starting in daylight and then moving the camera into darkness so we can see the transition.
Have you tried testing it in daylight with the photoresistor covered? That forces the module into night mode while there’s still ambient light, which helps us isolate whether it’s the IR-Cut filter or something else.
Sure, I actually already made two videos about this.
Video 1: the Arducam camera going from daylight into night vision. You can see the IR LEDs are not visible / the lighting doesn’t show up in the image at all.
Video 2: made immediately after, this one shows a Eufy night vision camera pointing at the Arducam. On the Eufy feed you can clearly see the Arducam’s IR LEDs lighting up.
So comparing the two, it really looks like the photoresistor is working and turning the IR LEDs on - the LEDs are definitely emitting. The problem is that IR light isn’t making it into the B0205’s own image. I’ll send both files over privately since they’re a bit large to attach here.
Thanks, got the videos. That’s actually a really useful comparison.
What you’re describing matches an IR-Cut filter that’s stuck in the “day” position. In night mode the filter should be moved out of the optical path so the sensor can see IR. If it doesn’t move, the IR light gets blocked and even with the LEDs blasting you’ll get a very dark / black image.
A few things to check if you can:
Listen closely when it switches - you’d normally hear/feel a small click from the IR-Cut mechanism as the coil actuates. Any click at all?
If you have a multimeter, you can probe the IR-Cut coil connector. You should see a short voltage pulse (roughly a few hundred ms) at the moment of switching.
Try the daylight + covered photoresistor test - does the filter move then?
That should tell us whether it’s the mechanism itself, the driver circuit, or a control signal issue.
No, I don’t hear any click when it should be switching. Silent.
I don’t have a meter handy right now, but I can try to get one.
In daylight with the photoresistor covered it still stays dark - same black image, no change in behaviour.
So the LEDs are on, the sensor is triggering night mode, but the filter never seems to move. Does that point to the filter being physically jammed, or could it be a dead coil/driver?
Given that the photoresistor is confirmed triggering (we know from your video 2 the LEDs fire) and there’s no click and no image change, it’s most likely the IR-Cut assembly itself - either a mechanically stuck filter or a failed coil/driver on the small IR-Cut board.
One more thing worth doing since you mentioned you already have a second B0205 for another project: it’s a good comparison unit. If you can, connect that second module to the same Raspberry Pi 4B+ and run the same day->night test. That tells us whether the problem follows the camera module or whether it’s something on the host side (e.g. power/USB).
If the second module switches and images correctly on the same Pi, we can confidently say it’s a hardware fault on the first module specifically.
Good call. I hooked up the second B0205 to the same Pi and it behaves normally - you can hear it click at the transition and the night image is fine, IR lighting visible as expected.
So the Pi, cable, and setup are all fine. The fault is definitely on the original camera module. I wasn’t sure I’d even use that second one, but at least it proved the point.
Day/night sensor (photoresistor): working - it correctly triggers and the IR LEDs illuminate (confirmed by your Eufy cross-check).
IR-Cut filter: not switching - no click, no image change in night mode, and the same test works fine on a second B0205 on the same Raspberry Pi 4B+.
Therefore the issue is isolated to the IR-Cut mechanism/driver on the original module, not the host or the sensor.
We haven’t nailed down whether it’s a jammed mechanism or a failed coil/driver without a resistance/voltage reading on the coil, so this isn’t resolved yet.
Practical options in the meantime:
You can keep using the module for daylight only.
If you’re comfortable opening it, you can manually park the IR-Cut filter out of the optical path, but then it won’t be reversible for daylight use without re-inserting it.
For night use, since the LEDs and sensor are fine, a module that isn’t doing IR-Cut switching (or the second module) is the more reliable route.
If you can grab that meter reading on the coil, post it here and we can say for sure whether it’s mechanical or electrical.