Hey Guys,
I'm new to audiomoths. I just purchased two. I'm trying to figure out a case situation for them. I designed and 3D-printed a case and discovered that I get noise and beeping if I try to record while the Audiomoth is in the case. I've also found that the beeping and noise happens if I try using a plastic bag as a case.
The beeps look like this.
Is this a known issue and has anyone else experienced this? Both audiomoths do it and they only do it when inside a case.
Try it out at 48kHz. That's the one we tend to focus on the most.
Hi again - using the Sandisk Pro Extreme Pro and Energizer Max batteries. The "tick" seems to only have occurred so far when using "Custom" mode and not in any of the files we have in "Default" position, but I've yet to go through enough to say this more than anecdotal. Would being set to 32 kHz be a problem? That is the other thing I changed on my second set of deployments, since I didn't think I needed the full 48 kHz yet and figured it would save battery some.
Yes in 32 kHz !! 16384/32= 512 ms !! Here we are !! Thanks for the explanation.
We notice a similar effect with our new cases where closing the case over-pressures the acoustic vent a little resulting in less sound transmission and then the SD card interference becomes more apparent. We'd seen a similar thing with plastic bags before but have never really had a plausible explanation - one possibility was physical noise from the SD card, generated by internal heat, showing up somehow. It also tends to be worse as the battery voltage decreases, which might be why you see it with the rechargeable batteries. In the next hardware revision we are changing the power supply circuitry to better suit rechargeable batteries and to better filter the SD card noise. That should reduce it further.
Are you recording at 32kHz? The SD card write interval in seconds is given by (16384 / sample_rate) seconds.
Hi Alex,
I use Eneloop Pro rechargeable batteries and Sandisk ultra 32 or 64 Go SD cards.
The little noise appears every 516 ms, and is faint and high pitched. And sometimes louder, but rarely.
No problem for me because I'm recording crossbills. But of course it's interesting to try to find the reason. Only when the Audiomoth is in a plastic bag.
Hi, This is noise from the SD card writing. What make and model of batteries and SD cards are you using?
I also just came here to say the same thing - just got 6 of them in the latest group buy and there's an audible 'tick' exactly every second on at least one of the devices. It's anecdotal for now but it seems to be only happening when in Custom timer mode, as the first set of recordings I did in 'default' mode didn't have this issue. I am also using a plastic bag.
Hi everybody,
I have the same problem, with my 2 audiomoths, only when they are in a plastic bag. However, because I'm just recording birds and the "beep" in upper in frequency, that's not a big problem for me.