Recording regimen is not working properly

Hi everyone! So, I'm involved in a project where we use 40 AudioMoth devices (version 1.1.0) to sample bird vocalisations at dawn chorus and around sunset time. I've updated every AM device to firmware version 1.4.3 and used Set Time and checked the Local Time option on Configuration App (UTC -3). I created a regimen of continuous recording (for example: 06:30-08:30 and 17:50-18:50). Recording at 48kHz, Medium gain, Enabled LED, Enabled low-voltage cut-off, Enabled battery level indicator. Everything else is turned off. Everything packed up with fresh alkaline batteries form Duracell (reading was >4.9V). Everything with brand new FAT-32 formatted SanDisk 32GB Extreme microSD. So, I'm in the process of downloading the data collected and I'm surprised to find that after 15 days on field some of the devices stopped recording on day 3. When retrieving the devices from field sites I saw the green light flashing in the Custom mode - indicating that it was working properly and just waiting to record on next schedule. Batteries are still good after 15 days (4.2V-4.5V). Can someone shed some light on what could be the problem? I saved the configuration file and applied the same configuration to every device. So it doesn't seem to be human error. Any input to solve this problem would be greatly appreciated. Thanks in advance! Sincerely, Humberto Mohr

8 comments

8 Comments

Andy

Aug 27, 2020

Thanks for the additional info, where were these devices acquired? The "more info" problem is normal, it takes a while for the OS to read and cache that information it should appear after a while.

H Mohr

Aug 28, 2020

Replying to

https://www.labmaker.org/collections/earth-and-ecology/products/audiomoth-v1-1-0

Andy

Aug 27, 2020

Is it just that one device that has a weird clock issue?

H Mohr

Aug 27, 2020

Replying to

No, many of them. Every device that stopped working before planned had it's clock messed up. By the end of the day I will be able to give precise numbers on how many of the 40 AudioMoth devices stopped working properly. I just arrived from field and I'm in the process of sorting things out. I would say around 20 or more. In the meantime: when I move the recorded WAV files to an external HD, the information on "More Info" section disappeared. Is it normal? Info and comments are visible only in the folders where I downloaded the files straight from the microSD, but not on the copied files I moved to an external HD.

Andy

Aug 27, 2020

Thanks for providing the additional information. The temperature measurement is unusual, what sort of environment are these deployed in and what enclosure are you using?

H Mohr

Aug 27, 2020

Some additional info: I've updated every device to firmware version 1.4.4 expecting it solved the problem, because we're amidst a big project involving the federal government and the devices must be in the field to collect data. After updating firmware, formatting microSD cards and configuring schedule all over again I plugged the devices back to computer to check if the clock was ok before deployment and it seems to be ok.

I noticed that on the devices that stopped working around day3, the clock was messy: each second was taking 3-5 seconds to pass and the exact time was nowhere near where it should be. Now I'm worried that not even the 3-day data can be trusted, because I'm not sure if the recordings started at real time.