I’d like to share a low cost design for water resistant cases for AudioMoths that I created (instructions in the attached image). I’d say it is water resistant rather waterproof as the hydrophobic fabric will allow water to penetrate if the water is flowing onto it under pressure. I initially made these with the cloth glued to the inside of the case but I found that water gathered on the outer lip of the drilled hole and once enough water had accumulated then leakage occurred.
I have tested these these under a running tap and during light rain (1-3mm) and can happily report that they keep perfectly dry inside.
A rough guide to cost is as follows:
junction box= €3
hydrophobic cloth (for a sample pack with 50 squares that could make 50 cases) =€10