How to use this Water Detection Sensor?

I just purchased the water detection sensor (sku PR46-14). I’m planning to connect it up to a Raspberry Pi 4 via I2C. I see it also has 2 GPIOs, which I’m planning to wire an on/off switch to. Can someone please point me to the API library compatible with this sensor and instruction on how to read the I/Os (preferably in Node Red)?


That device utilizes a PCA9536. There will be sample applications available online for that IC specific to your software development language.

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Thank you for your answer, I think this is the repo you’re referring to (GitHub - ncd-io/ncd-red-pca9536: PCA9536 Library from How about the wiring for the extra GPIOs? There are 4 unused pins labeled “Pull Up”, I’m assuming I can hook up a switch to them to monitor its status?

Hi Brian,

The additional IO lines for the PCA9536 are not exposed via any accessible hardware connections on that product. It was developed only to be a water detection sensor.

Thank you,
Travis Elliott

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