Eric, The Enerloop batteries are only rated to -20C so unlikely to be usefull at those temperatures. https://www.panasonic.com/global/energy/products/eneloop/en/lineup/eneloop.html I the UK, for High Altitude Balloons, we use Energiser Ultimate Lithiumn batteries that are rated for -40C. https://data.energizer.com/pdfs/l91.pdf At the temperatures your are considering you may need to de-rate the battery capacity, see the chart in the linked pdf. Please let us know how you get on. EAP

Martin, I did see something similar on one of the devices I have been testing over the weekend. I did have the detectors quite close together and the battery voltages were quite low ~4.2V. I've moved the devices further away from each other and fitted new batteries. I'll let you know if I continue to see more of these pulses.

@John Connock I am having the same problem but it's related to the version of Powershell on my system. According to: https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/format-hex?view=powershell-7 The -Count option was introduced in version 6 , while my system is 5.1.18xxx. You can check your version number with this command at the Powershell prompt: Get-Host | Select-Object Version So I think we will have to upgrade our versions of powershell, before Alex can help us. If you can use R on linux, the following hacky function will get you the temperatures: get_AM_temperature <- function (t_file_name) { if (!file.exists(t_file_name)) { t_err_msg <- paste0("File: ", t_file_name, " not found.") stop(t_err_msg) } t_cmd_string <- paste0( # Build Linux shell command string 'head -c 500 ', t_file_name, '| grep -a -o -E "temperature was .{0,5}"' ) system(t_cmd_string, intern = TRUE) } This just gets the temperature rather than the whole header.

Alex, Thanks for the quick response. The link to the filter design pages is very useful so will look at how this works some more. I didn't realise you had already addressed the write out config idea, sorry for not checking first. I've never looked at node.js before but the code looks easy to understand so I'll see what I can do to script it. Finally the weather looks better this evening so I'll try for the back-back recordings. Regards. EAP

Alex, Peter, and team. Thanks for what looks to be a set of very useful improvements. I'll run some field tests giving back-back comparisons between the 1.3, 1.4 and triggered firmware versions and post the results here. Unfortunately the wet weather last night prevented any attempts at bat recordings. A couple of questions and inevitable feature requests. 1) What is the roll-on /roll-off of the new filters? Looking at figure 5 in the white paper the filter looks to be quite slow with gain = 0.2@24kHz and 0.8@72kHz, so sensitivity of the detector will vary with frequency through most of the range of interest for bat recordings. 2) Would I be right in thinking at that if the LFP were set at half the sample rate then aliased signals would be removed (or at least significantly attenuated)? I very much appreciate the Amplitude Threshold Recording and can see this being very useful. A few feature requests if I may: a) As more and more parameters of the AudioMoth become configurable it becomes increasingly important to be able to audit the configurations actually used in the field. Please consider adding functionality so that on start-up (switch moved to "Custom") the AudioMoth writes out the current configuration to a txt file on the SD card. Alternatively add the configuration information to the INFO chunk in the WAV header. b) Can the file expansion functionality be broken out from the main configuration app, preferably into a stand-alone program that can be scripted into batch files on Windows or Linux shell scripts? c) Can the file expansion functionality be extended to generate a new file of max duration X seconds at the start of each chunk? This would be very useful when working with classifiers such as TadaridiaL which have an input file size limitation. As these last two features are probably edge cases from your perspective so if I wanted to look into this myself should I start with "decompress.js" and the "Expansions" folders on GitHub? Finally, any news on the "AudioMoth Labs" site that was talked about last year? Again, many thanks for all your hard work. EAP

Sarah, On my system I am able use WarbleR and your code to process .wav files generated by an AudioMoth, so it it's unlikely that there is a systematic problem. Can you post one of the files that are causing problems, and I will check it on my system? That way we will know if it's a problem with the files or with your R installation. Kind regards. EAP

Are there any significant differences between the schematics for version 1.0.0 and 1.1.0 boards? Asking because CircuitHub only give schematics for the earlier board. See Version #1 and #2 here: https://www.openacousticdevices.info/support/device-support/audiomoth-schematics Many thanks. EAP

Valdimir, Please see my reply to Peter, Provided you have access to a command terminal the following command should fix you problem: sudo usermod -a -G dialout MY_USER_NAME provided you substitute "MY_USER_NAME" with your name on the computer. Please let me know if this works or if you need any help. Regards. EAP

Peter, Many thanks that fixed it. Before applying the chmod you suggeste, I checked the permissions on the port, which I should have done earlier. Anyway ls reported the following linux$ ls -alt /dev/ttyACM0 crw-rw-rw- 1 root dialout 166, 0 Apr 10 11:44 /dev/ttyACM0 So it appears the port is owned by root and only accessible to members of group "dialout". A bit of digging with Google shows that this is a long term issue/feature with Ubuntu and derivative distributions e.g. Mint. The recommended solution is to add the user to the "dialout" group with the following command: sudo usermod -a -G dialout MY_USER_NAME This fix will survive reboots of the computer and multiple plug/unplug of the AudioMoth. Many thanks for your help. EAP

Hi Peter, I had been wondering where the log files were hiding, now I know! The file itself is not too long but basically contains the following repeated for each attempt I made to flash the AudioMoth [2020-03-30 17:02:13.536] [error] { constructor: 'Error', stack: 'Error: Error: Permission denied, cannot open /dev/ttyACM0' } I checked the permissions on /dev/ttyACM0, and got the following: ls -alt /dev/tty* crw-rw---- 1 root dialout 166, 0 Mar 30 16:56 /dev/ttyACM0 I also tried to run the flash app under sudo, but received the following error message: Running as root without --no-sandbox is not supported. Finally: I tried running from a terminal rather than from Nemo file manager as I usually do, the result was the same but following is the output at the terminal: ~/linux$ ./AudioMothFlashAppSetup1.0.1.AppImage Bar created. Incrementing progress as connection process is complete. Setting progress bar maximum: 925 Setting version info: 1.3.0 Aborting progress. Flash bar aborted Gtk-Message: 17:02:13.573: GtkDialog mapped without a transient parent. This is discouraged. Clearly this is something in my configuration but I'm at a bit of a loss as to how to proceed. Hopefully there is something in the above that may give you an idea what needs to change. Many thanks for your help. EAP

Hi, My Round 7 AudioMoths arrived today :-) Build quality looks very good and I can't wait to get these out in the field. A big thanks to everyone involved in making this happen. EwanP

For anyone running analysis in R, Steve Markham of the Bat Conservation Trust, has an article and code for calculating sunrise/ sunset times on his rbats-blog: https://rbats-blog.updog.co/2018/04/12/bat-night-times/

Hi Alex, The approach you describe would be very useful so I am looking forward to seeing it in the next release. Semi-related question: will it still be possible to set the device record/ sleep intervals within the above recording period? I'm asking because the classifier I use is limited to recordings of 5s or less, so I configure my AudioMoths to record for 5s and sleep for 0s. Thanks. EAP

Alex, Is there any news on the timing of the Audio Moth Labs site, and the firmware with HPF for bat detecting? I'm keen to test any new firmware with a HPF and auto SRise SSet recording intervals. Finally is there any way to have the Audio Moth write out its configuration to the SD card. This helps greatly with traceability when archiving recordings. Many thanks EAP

Problem Solved On re-reading the instructions I realised the AudioMoth had to be in Program mode (Step 6 in the instructions) in order to appear as a new port. Thereafter all went OK. Many thanks. EwanP

Peter, First, thanks to you and the team for developing this wonderful device, which as so many potential applications. While attempting to update to firmware version 1.2.2 I have run into a problem with the "flash" utility which reports "No serial ports found". What seems bizarre is that I've had this outcome on 3 computers; two ruining windows 10, and one running Linux Mint 18.3 Cinnamon 64-bit! In each case the configuration app is able to communicate with the AudioMoth over the USB cable. On the Linux machine I get the same outcome with "./flash" or "sudo ./flash" so it's unlikely to be a permissions problem. If it helps diagnose this problem the following is the results from "lsusb" :> Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 005: ID 04f2:b15e Chicony Electronics Co., Ltd Bus 001 Device 011: ID 10c4:0002 Cygnal Integrated Products, Inc. F32x USBXpress Device Bus 001 Device 009: ID 046d:c517 Logitech, Inc. LX710 Cordless Desktop Laser Bus 001 Device 008: ID 0451:2046 Texas Instruments, Inc. TUSB2046 Hub Bus 001 Device 004: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub Bus 001 Device 003: ID 138a:0007 Validity Sensors, Inc. VFS451 Fingerprint Reader Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub and from "dmesg" after connecting and then disconnecting the AudioMoth:> [409101.914480] usb 1-1.4.4: new full-speed USB device number 12 using ehci-pci [409102.009750] usb 1-1.4.4: New USB device found, idVendor=10c4, idProduct=0002 [409102.009757] usb 1-1.4.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [409102.009763] usb 1-1.4.4: Product: AudioMoth [409102.009767] usb 1-1.4.4: Manufacturer: openacousticdevices.info [409102.009771] usb 1-1.4.4: SerialNumber: 0100 [409102.012165] hid-generic 0003:10C4:0002.0007: hiddev0,hidraw2: USB HID v1.11 Device [openacousticdevices.info AudioMoth] on usb-0000:00:1a.0-1.4.4/input0 [409152.921322] usb 1-1.4.4: USB disconnect, device number 12 Clearly I am doing something wrong but would appreciate suggestions on how I can resolve this. Many thanks EwanP