Waterproofing the Sound Lure Unit

Above: Unit and casing showing connection cables.

Challenge: One of the key aspects of producing a successful unit is the issue of waterproofing.   The unit has been created, it has been tested, and there is not a question of it working in the short term.

The issue in long term is moisture - there is considerable rainfall in our region (Taranaki) during winter.    As a consequence the unit is going to be exposed to considerable direct rainfall.  This can be addressed by placing the unit inside another box (such as a stoat trap) and placing it inside a plastic box - we have 3D Printed these in the past, designed by students.   We have already lost one unit as a result, when the rainfall entererd the box, despite initial attempts at water proofing.   The next approach is to use a manufactured IP rated waterproof box.    Once the box was used to house the Picaxe and breadboard (as shown in photographs above).   There were a number of features that need to be explained.

Above; Close up of cords connecting to external bolts.

Left:  While the box itself is waterproof and the screws that join the lid on the unit are outside of the box, there is the need for two outputs - one being the solar panel (here shown by the brown and blue cords) and the speaker (the while cords).    The cords in both cases correct directly to a nut and bolt which has been drilled through the box.  They have been sealed on both sides using blue tack with the the tightened bolt.    This will mean that both the solar panel and speakers will be housed seperately from the main unit.  The speakers that we are using have been sourced from Aliexpress and are in the two-three dollar range.   The solar panel is relatively inexpensive, coming in at under $10.00.   The intention is to house both externally but to have them disposable.   With the box, the sealent and the water proofing we are anticipating minimal moisture able to enter the unit.

Above: The full unit in deployment.

Left: The completed wired unit in place inside the IP rated box.   We will be including with the box recycled Silica Gel packets to aid the absorbing of any moisture that is able to enter the box.   Furthermore we are experimenting with wood and 3D Printed designs to minimise the level of moisture.

The final phase of testing of the prototype is to deploy the unit as shown in the photographs in exposed outdoor conditions, including anticipated rain to measure its reliability to the elements.   We are looking to measure any moisture that can develop inside the unit, measure the sound quality from the unit outside of the box and check to maintain the amount of damage that occurs to the unit (if any).  Should there be significant issues with the unit we should be able to detect this prior to our first V3.0 unit deployments which are occurring shortly.   These deployments are different from previous deployments as they are being made at external locations where there are already existing trapping projects or groups that are removing pests from the environment.   In these cases unit which we were able to receive a donation for are being deployed to the New Plymouth Airport and Lake Rotokare Scienic Reserve.   These units are being deployed in exchange for the trapping data and evidence supplied by both these organisations.   We have similar agreements in place with a number of other organisations which we will be able to meet subject to funding.

If you are interested in using our units in a deployment can you please get in touch with us by emailing us at myles.webb@gmail.com if you have any queries.