The last couple of months have seen us make more improvements to our Cacophonator hardware. The changes made have been driven by the demands of upcoming projects and targets.
Up until now we've typically run our devices on mains power. We've preferred sites which are near native bush but have access to a wall socket (sometimes with long extension cords!). This has gotten us quite far in terms of testing our prototypes and gathering footage to train our machine learning classifier but obviously isn't going to be a long term solution. Being able to run on battery power opens up a huge range of new areas to our devices.
The Cacophonator hardware now incorporates a buck-boost converter which allows it to work from a number of types of power sources including various battery technologies with differing output voltages (which change as the battery discharges). The buck-boost converter also continues to support mains power using a classic "wall wart" AC adapter.
We explored a number of options for battery power and after a number of false starts and experiments we've found a New Zealand based manufacturer who will make weatherproof lithium-ion battery packs which meet our needs exactly. These packs have performed well in the cold and in heavy rain. A Cacophonator can run for 5-6 nights (turning off during the day) on a single battery pack and we have ideas on how to extend battery life further.
The other major improvement in the new revision of the Cacophonator hardware is the addition of built-in audio support. An exciting area of research that we're about to embark on is the use of sound lures to bring predators closer to our devices. This obviously means that we need to be able to produce sounds from our devices.
Initially we were hoping to use self-contained, off-the-shelf consumer speakers but our initial trials ran into numerous problems. They require their own power cable which complicates deployment and they tend to be too "smart", turning themselves off when no sound had played for a while.
The Cacophonator hardware now includes its own audio amplifier and digital-to-analog converter (DAC) so that a simple passive speaker can be connected to it for sound output. To ensure survival in adverse conditions we are using marine grade speakers designed for mounting on boats. Not only is this solution simpler and more robust, it's also significantly less expensive.
We're very pleased with our new hardware platform and what it will enable. We can't wait to get these out in the field!
See this previous article If you're interested in learning more about our hardware.