isolating open wet usbport from controler

Hi,

I got a question:

I have a simple arduino device that I want to use outside in very wet conditions. In my perfectly watertight casing I have a IP67 usb connector that is watertight without a cap.

Is is possible to isolate the connector and arduino chip digitally using a buffer gate (tri state) like SN74HC125N so it wont get a short if the connector gets wet and shorts?

Many thanks!

yes.

you can have the power and signal lines to the port disconnected unless in use. add a button to test state and power the port.

in most cases, just water will only carry a few ohms and not offer a good electrical connection.

As a consumer standard, USB is designed to take a fair amount of electrical abuse, however plugging anything into a connector that isn't 100% dry will cause corrosion and confusion for both devices.

You could try back filling the connector with silicone grease each time you unplug the cable. It'll keep the water out to some degree.

An IP68 connector is what you need.

dave-in-nj: in most cases, just water will only carry a few ohms and not offer a good electrical connection.

Surely , you mean "in most cases, just water will be an extremely large number of ohms and not offer a good electrical connection."

It is a common mistake to make, I've noticed in the past that people cannot easily differentiate between low resistance, and low conductivity (the inverse of resistance).

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