Forum Posts

Wes Bancroft
Apr 01, 2021
In Enclosures
Hello all you AudioMoth’ers, So it turns out that the update to my previous post (https://www.openacousticdevices.info/support/enclosures/summary-of-enclosures-to-date ) has taken a little longer than I anticipated (TWO years!!... sorry!). But, maybe, better late than never? Anyway, it looks like enclosures have moved on in that time, with a quick skim through this forum showing 3D printed cases and the official AudioMoth IPX7 cases having risen in popularity/use. For what it is worth, here is what we settled on to use for frog calls in south-western Australia (with great success last season; April-June 2020). We have adapted small lunch-box containers by adding a foam insert and a metal loop for cable-tie retention, and giving them a coat of paint to get this: We’d done some rough field testing with a prototype or two and found that, much to our very pleasant surprise, we did not need to include a microphone ‘hole’ to successfully record the target frog calls (dominant around c.400 Hz). [This still seems to be the sticking point for most cases… letting the sound in but not the weather.] This surprised me greatly (I still don’t fully understand – I have a lot to learn!) but containers without a microphone hole in them performed as well, or better, than those with a hole covered with sticky tape (for weather proofing) at any distance up to 20m from the sound source. At distances over about 10-15m, they also performed almost as well as an AudioMoth with no case at all. So we decided on retaining the integrity of the containers (maximum weather-proof-ness) and not adding a microphone hole. Step by step, here’s how we made them (photos of various materials at the end of the post). (1) Bought the containers: 200 mL rectangle KLIP IT containers made by sistema (https://sistemaplastics.com/products/klip-it-rectangular/200ml-rectangle) and purchased from our local supermarket. (2) Attached the metal loop: we used a plastic-specific superglue (local hardware store) to attach metal picture frame hangers (also from the hardware) to the lid of the container. (3) Painted the container: the secret to success here (learnt from early failures, where the paint flaked off) was to give them a couple of coats of a spray-on plastic primer first. Then we just used the cheapest enamel spray paint we could find. A couple of base coats of black followed by a top coat of ‘mocha’ (interestingly, this light colour was subsequently really important in the camouflaging). Then a partial squirt (using artistic licence) of dark green and brown to complete the camouflage look. (4) Made the foam insert: we used 10mm thick expansion joint filler as the foam (bought from local hardware store) and cut this to shape with scissors and glued it together with a hot glue gun. We had a base layer (full container size) and then a half-length layer on top which meant the AudioMoth unit sat nice and snug at one end of the container, with its microphone pressed against the lid (when closed). There was also room for a little bag of silica gel (as a desiccant, just in case) in there as well. Then we inserted a flashed, configured and switched on AudioMoth, ready for deployment. The KLIP IT containers have a recess in the lid so we mounted the units (using a cable tie) on angled tree branches so any rainfall ran off (but not vertical to avoid moisture getting in under the lid). They performed great though the austral autumn and winter (we brought most of them back in by spring). There was no water ingress into any unit, as far as we could tell. One unit from last year was collected today – 280 days since it was first placed out! It was incredible how well this had survived the Australian summer (direct sunlight, heat and strong winds etc.). The only two minor issues we had were (i) the unsticking of a couple of the metal hangers (when the unit was removed, this fell off) and (ii) we had made such lovely enclosures that a family of ants decided to set up their home in the container-hinges of one unit. We’re not sound engineers (or high-level analysts like many of you reading this) but the recordings were well and truly good enough to identify our target species by human ear (the next challenge is getting a computer to do this for us – an entirely other topic). So you’re probably wanting to know how much we spent? For each case the materials (container, foam, hanger, super glue, paint primer and spray paints) would cost us today c. $4.39 (AUD). That’s about $3.34 (USD), €2.85 (EUR) or £2.41 (GBP). Plus sundries like the hot glue gun, silica gel and cable ties would still land us below $5 AUD a case (with, obviously, time not factored in). We were very happy with that. All the best with your endeavours in the AudioMoth case/housing/enclosure realm, wes
Finally - an update on our enclosures (from snack boxes) content media
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Wes Bancroft
Apr 12, 2019
In Enclosures
Hi AudioMothers, I’ve been doing some research towards making enclosures for the Round 6 AudioMoths that we have on order. For the benefit of others, here is a bit of a summary of some of the attempts that I've seen so far: (1) a zip-lock bag (the ‘base model’). This is rain-shower-proof (but not fully weatherproof, I don't think) and the sound recording doesn't seem to be affected by the thin plastic over the microphone. Simple, cheap, lightweight. (2) a little click-lock container with a hole drilled in it for the microphone to listen out through, and some Scotch tape over the hole. In this example the container wasn't watertight to begin with. https://www.openacousticdevices.info/support/enclosures/box-for-audiomoth (3) using a click-lock container (with a drilled hole) and some clingwrap over the hole. Not certain how waterproof the end result of this was. https://www.openacousticdevices.info/support/enclosures/an-alternative-case-for-audio-moth (4) using an electrical junction box (with a drilled hole) and some hydrophobic cloth. Still not fully waterproof. https://www.wildlabs.net/community/thread/554 (5) using an IP54 ( Ingress Protection: 5 = dust protected and 4 = splashing water protected... see https://en.wikipedia.org/wiki/IP_Code) electrical junction box (with a drilled hole) and waterproof acoustic membranes (stickers). I think I like this the best out of all of these because the boxes have moulded eye-holes such that you can attach with cable ties and it all sounds reasonably water-tight. But the stickers are really expensive and didn’t always hold-up in field conditions. https://www.openacousticdevices.info/support/enclosures/case-for-audiomoth (6) adulterating a waterproof/dustproof case. This seems only a step or two short of putting a tiny detector in a shipping container for deployment. But it might be good if security is an issue. (I think I'm going for the if-I-hide-it-then-no-one-can-see-it-and-therefore-can't-steal-it approach.) https://sites.google.com/view/audiomoth/housings-or-cases/samson-case (7) a custom 3D-printed case. Not sure how you print the rubber seal? Is that possible? Also not clear how the microphone has access to the outside world? https://www.thingiverse.com/thing:3292311 (8) the Open Acoustic Devices’ acrylic case. In the pipeline, it seems. See these threads: https://www.openacousticdevices.info/support/enclosures/about-protective-measures https://www.openacousticdevices.info/support/enclosures/possible-case-for-audiomoth While not a full solution, there was theoretical discussion to suggest the addition a ventilation port such that any condensation can evaporate out of the case. I don't know what to think about this. If the air holes faced down and were underneath some sort of sheath then it may work? Provided that the case was always mounted 'right side up'. But, presumably, this would also let humid air in? https://www.openacousticdevices.info/support/device-support/audiomoth-housing I have also contemplated popping a desiccant in the case, just to keep things happy and dry (and to protect from condensation etc. on the inside if the case is in the cool, then the sun, then the rain, then the full sun again, then the cool etc.). Silica gel baggies seem simple and cheap and the way to go. This has been mentioned a few times in the support forum here too. So, for our planned study (in south-western Australia – and the climate that we have here), in summary, I think we need to use an enclosure that: (i) is generally weather-resistant (i.e. rain and wind but not necessarily immersion; and we don’t experience frost, snow etc. or crazy, prolonged humidity either); (ii) has loops through which cable-ties (or similar) can be threaded for securing the enclosure to a branch/stake etc.; (iii) has a hole through which the microphone can hear the outside world - but have this hole weather-proofed in some way. (I think this weather-proofing of the microphone port is where all the challenge is in any of the above systems).; (iv) is reasonably easily open-able such that we can get the AudioMoth units in and out without too much fuss (we’ll be doing this on a regular basis); (v) has enough room for a backup bag of desiccant on the inside; (vi) is cost- and time-effective to construct. If anyone has any other input at this stage then it would be much appreciated. Otherwise, I’ll update you all when we decide on our approach. Thanks, wes
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Wes Bancroft
Apr 12, 2019
In Configuration Support
Hello Open Acoustic crew, and thank you so much for the link to your recent paper on testing of the acoustic detection algorithms for the AudioMoth (https://www.openacousticdevices.info/publications). This is exactly what we'd like to do here in south-western Australia; to use the AudioMoth to 'listen' for (and record, where applicable) a single target species of frog (and avoid a large amount of post-collection raw data processing). Can you please offer me some guidance as to the steps that I'd need to go through to get that algorithm, modify it for our target sound, and then load it onto an AudioMoth? We're keen to give this a go! Thank you.
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Wes Bancroft
Oct 05, 2018
In Device Purchase
Hi all, I run a little citizen science frog monitoring project in the south-west of Western Australia. I'm super excited because I've just managed to secure enough community funding for 10 AudioMoth units. But I saw in the recent End of Summer Update that there is a new revision of AudioMoth ("version 1.1.0") to make it more robust. Is that a revision to the actual physical unit? If so, do you have any approximate timing as to when that will be in production? (I probably only have one shot at buying these units so don't want to buy the current model if an improved one is not too far away.) Any insights would be most appreciated. Thank you. wes
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