Hi,
Despite the IPX7 Waterproof, one of my AudioMoth {1.2.0} took on water. One of the batteries seems to have leaked.
Although cleaned and dried, in USB connection, the Apps do not see the device. On the LED side: the red LED remains fixed, the green LED flashes.
Of course the water that leaked onto the AudioMoth had consequences on the electronics... but just in case, do you have any ideas for possible repairs / things to search for?
Thanks.
Hi,
Which case was the AudioMoth deployed in? With the 3.5mm jack fitted it will not fit within the standard waterproof case. If you play the chime from the AudioMoth smartphone app, does the AudioMoth start recording? The solid red and flashing green LED means that the AudioMoth thinks it is in CUSTOM mode and has not had the time set and is waiting to listen for the chime in order to set it.
Alex
Is it possible to modify the firmware so that the data stored on the SD card can be accessed via USB connection, instead of removing the card from AudioMoth and connecting it to a PC with a card reader?
If the units can be permanently connected to a computer, we have a python script to record from many (>12) on one Linux PC, saving data directly to flac files. We use the audiomoth mic firmware so no sd card and usb powered.
I just bought my first AudioMoth, along with the weatherproof case. A couple of questions:
included in the box was a small plastic envelope containing two small round items - what are these for? Looks like maybe to replace the case opening cover when <what> happens?
I'm recording NFCs so am placing the AM flat facing upwards. What does this mean if it rains overnight? I'm thinking the cone around the mic hole will fill with water. Should I put it in a ziplock bag if rain is expected, and if so how will that affect sound pickup?
Inside the plastic ziplock bag are two spare Gore GAW334 acoustic membranes. The membranes may need replacing over the lifetime of the case, depending on the deployment environment. For example, some insects and birds can potentially pierce the membrane surface over time. The installed membrane can be inspected by holding an open case up to a light source, if there are any pin holes of light passing through the membrane it will need swapping out.
If the case is placed facing upwards rain water will pool inside the cone, the AudioMoth IPX7 Case is designed to be deployed with the microphone facing horizontally. Placing it inside a ziplock bag should prevent this. There's a good discussion on using ziplock bags here and comparisons of how recording quality is affected here.
It should be very positive, in terms of reliability and better sound inlet, to manufacture the Audiomoth-USB mics with a better-designed and larger in diameter orifice for the MEMS mic sensor. See attached pic. Could it be possible?
?
Hi, It might be possible to experiment, however, the current MEMS microphone footprint and port is manufactured as per the Knowles design guidelines. Alex
Is there any technical possibility of enabling an AudioMoth to somehow emit power and storage status. I would like to use a separate LoRa device, to check the status of AudioMoth, and broadcast it. The use case is I will place Audio Moth devices on private land, where I need an escort, the boundary is a few hundred meters away, so I could ping it, and only request access when needed. Arguably, I could probably predict the storage capacity and do some sums, and just provide a lot of stored energy. is this what others do?
Hi Matt, It would be possible to connect a LoRa radio to the AudioMoth GPIO connections and modify the firmware to transmit status information. I'm not aware of anyone currently doing this, but Open Acoustic Devices can do custom firmware versions for specific requirements under individual consulting agreements. Alex
There are signs of corrosion on the Audiomoth circuit board, but it still works. Can we still use it? If yes, should we try to get rid of the corrosion?
Hi Emmanuel, Yes, clean off any loose corrosion with a dry brush and it should be fine. Alex
Hello, I have been having issues with getting some GPS hats to get a fix.
I have successfully soldered some Audiomoths and GPS hats together, and they have been able to get a GPS fix from inside a lab room inside a building, far away from doors and windows. However, two other Audiomoth/GPS hat units have not been able to get a fix from the same location, even if close to doors and windows. I have been using a SETTINGS.TXT file that the functional units have been able to get a fix with. I can provide the file if it would be helpful to see it.
Both Audiomoths function properly with Audiomoth-Firmware-Basic and can record files using a configuration from the Config App that does not use the GPS hat. When I soldered the functioning Audiomoth/GPS hat units together, I used a multimeter to measure their resistances and connections, and…
If the files are blank then the GPS modules are not sending any data. This is unusual as they would have all been tested prior to shipping. Can you post some photos of the two GPS Hats affected with close-ups of both sides.
I need to synchronize the recordings of several AudioMoth devices with microsecond precision. I attempted to do this by turning the devices on approximately simultaneously in default mode and recording a reference signal both at the beginning (within a few seconds) and at the end of the recording, just before shutting the devices down.
Unfortunately, the signal at the beginning and the end of the recording is sometimes not captured.
I have three questions regarding this:
How long does it take for an AudioMoth device to start recording after being powered on (in seconds or milliseconds)?
At what intervals are recordings saved to memory (e.g., every minute, every 15 minutes)?
Are any recordings lost or skipped during the saving process, or is all data continuously stored?
Hi Elmar, Depending on the contents of the SD card it can take up to five seconds to open the file and start recording. In normal use, the AudioMoth firmware tracks this duration and adjusts it's preparation time so that the recording always starts at the required time. If you set the clock on the AudioMoth immediately before recording, and use a scheduled start time, then all the AudioMoth recordings will start at the required time. The realtime -clock drift can be up to +/- 80ms per hour so you will need to allow for that uncertainty. If you are recording outside you can use the GPS board and the AudioMoth-GPS-Sync firmware. This runs the GPS continuously during recordings and provides software to automatically synchronised recordings to +/- 1us. https://github.com/OpenAcousticDevices/Application-Notes/blob/master/Measuring_the_Accuracy_of_AudioMoth_GPS_Synchronisation/Measuring_the_Accuracy_of_AudioMoth_GPS_Synchronisation.pdf This firmware uses the pulse-per-second (PPS) output of the GPS throughout the recording. You probably won't be quite as accurate if you only synchronise the recordings at the start and end as the internal 48 MHz clock will drift slightly over the course of the recording due to the temperature fluctuations. If the temperature is consistent you'll get the best results. Also, 1 us is a lot less than the inter-sample period (22 us at 48 kHz), so you will need to be quite careful interpolating the recordings when you try to correlate the recording with the reference signal. We've done this in the past by interpolating the zero crossing times of the waveform.
The recording schedule is determined by whatever you set in the Config App. Data is written to the SD card continuously in 32 KB chunks during the recording. At 48 kHz this corresponds to 341 ms.
Alex
Hi AudioMoth Team, I have 2 AudioMoth Dev's running the AudioMoth-USB-Microphone v1.3.1, and no matter what I do I get buzzing noise. I tried gain, changing sampling rates, filtering, I messed around with AudioMoth Live and Play apps, nothing solves the problem. I took them outside and powered them with a battery and the sound remains. I have tried them with a Mac, a Windows laptop, a microcontroller, different USB cords and ports, etc. I noticed this post: https://www.openacousticdevices.info/support/configuration-support/buzzzing-sound-white-recording I am certain mine have never experienced water damage, and I have had this noise since I opened them. I assumed it was user error and that I would solve it at a later date, but nothing I have tried works. It can get better than it is in these recordings, but not by much.
Here are recordings from each of them, taken at 48KHz with Gain @ Low with no filters and no advanced settings,…
Hi Alex, The signal moves when I change to 96KHz or higher, it is then concentrated around 32 KHz. I started another recording indoors and walked outside, as I stepped outdoors the sound vanished. I then put the device into an ESD bag and walked back indoors and the sound returned but much lower intensity. I had tested it outdoors before but that was awhile ago and there could have been other stuff going on out there. Today it was relatively quiet. I also put my phone in airplane mode. I noticed its significantly worse by the entrance to the building and a bit worse near the entrances to specific rooms. My complete guess of a hypothesis is that its EMI from the door keycard tap system and probably other stuff. Hope this helps others. I have now covered the device in Kapton tape and I will then wrap it in aluminum foil. Best, Hudson
Hi,
I bought 5 Hydromoths in January 2025. 2 of them are having strange malfunctions. The other 3 will no longer connect to my computer with the configure app. The light doesn't come on when I connect them to the computer. The cord I'm using seems to work fine for other units.
1) is only recording for about 12 hours and then abruptly stops. It still has plenty of battery and plenty of space on the SD card. I've tried reinstalling the firmware, but didn't help.
2) Another recorder consistently has the clock running fast. I deployed it for about 48 hours (20 sec. out of every minute) and when I retrieved it had closer to 72 hours worth of recordings. I've used the same one 3 times, and this happens every time. I don't know how to fix this.
Thanks!
-Julia
Hi Julia,
Can you use the 'Summarise AudioMoth Files' option under the 'Process' menu in the Config App to generate a summary of one of the SD cards which stopped early to see what is happening.
The clock running fast is sometimes a sign of humidity damage to the HydroMoth. Can you contact andy@openacousticdevices.info about this one, and confirm when the HydroMoth was purchased.
Alex
I'm using a 1.2.0 AM. First it wouldn't configure after coming back from the field. Now it configures ok, but when I make test recordings sitting about 50 cm from microphone, they are very quiet (using default configuration - 96kHz and Med gain) - I tried increasing the gain, and certainly got more noise, but volume of recording was still very low. Any suggestions?
Hi, It sounds like this is water damage to the microphone. It may recover a bit if stored in a dry location. Alex
Hello,
We are currently trying to connect a solar panel to a charger and a lithium battery so the AudioMoth dev can be left in the field for a longer period. The linear battery charger (Adafruit bq25185 USB / DC / Solar Charger with 5V Boost Board) provides a constant 5V to the AudioMoth as long as there is enough sun and the battery is not empty.
The problem is that the AudioMoth measures this voltage and writes 5V (or "greater than 4.9V" to be exact) in the metadata of the recordings. As a result, we cannot get a reading of the actual battery voltage.
The charger board has a pin (BAT) giving the voltage of the battery. As we want to monitor the battery voltage, we are looking for a way to read the BAT pin with the AudioMoth dev. Would the GPIO port be able to read it?…
Hi Simon,
The easiest solution would be to use the Adafruit BQ24074 board as you don't need the additional 5V boost which causes the battery measurement problem, and it may also create some additional SD card write noise:
https://www.adafruit.com/product/4755?
The AudioMoth is then powered directly from the Li-Ion battery. The battery voltage will never exceed 4.4V when charging, and when there is no charge current, you will measure the true voltage of the battery.
Alex
Hello,
We want to use AudioMoth for bird and bat recordings and the recommended type (in the instructions manual) are lithium type batteries. Could you recommend any AA rechargeable batteries of this kind that would be best for AudioMoth?
Thank you
Tudor
Hi Tudor,
Yes, rechargeable NiMH batteries work well. Buy large capacity ones - 2800-2850mAh. Cheaper ones may only be 1500mAh capacity. Alex
I am looking for a device to monitor and identify birds in my woodlot in New Brunswick Canada. How long would the battery last in a 7/24 mode?
The Config App will tell you the daily energy consumption of any configuration that you set. The example below is for 24-hour continous recordings with 55 seconds individual WAV files and 5 seconds between them. Daily energy consumption is 280mAh and good quality rechargeable batteries will have a capacity of about 2800-2850mAh giving about 10 days. At sample rates of 48 kHz and lower, you can also select 'Enable energy saver mode' to save another 30% with a small decrease in recording quality. The final capacity depends a bit of temperature and the condition of the battery. The biggest variable in deployment lifetime in the choice of SD card as their energy consumption varies very widely - https://www.openacousticdevices.info/sd-card-guide - sometime by a factor of four. The energy calculations are for 32GB SanDisk Extreme (red and gold) cards which are reliable and low-energy. Larger cards will use a little more energy, but the difference between 64GB and 32GB is minimal.
Alex
Hi, I am using AudioMoth (version 1.1.0) for my data collection in India. I have some issues with a few of my devices:
1) One recorder doesn’t have a switch to turn the recorder on or off
2) One recorder is always showing battery level < 3.6V in the configuration app
3) One recorder is storing audio files, but it’s just white noise; the PCB of the same recorder is detached from the battery holder on one side.
Can someone help me solve these issues or connect me to people who can assist with that?
Thanks!
Hi,
Yes, connect the 'jack detect' pad to the adjacent 'ground' pad with a small jumper so that the AudioMoth knows that the microphone is there. Then, connect pin 1 of your jack, which is the 'sleeve', to one of the 'ground' pads, and pin 2 of your jack, which is the 'tip', to either of the 'L signal' pads. You don't need to connect pin 5.
The correct socket is available from GroupGets:
and from the UK shop:
What microphone are you planning on using?
Alex