The aim of the basic horticulture controller is to control the water supply to the planter boxes. It’s basically a limited controller, in the sense that I can either turn the water supply on or off, and I can only increase the soil moisture content and cannot decrease it actively. I tried a couple of cheap resistive soil moisture sensors but found them too inconsistent, and they corrode easily. There are some online designs for capacitative sensors, but I was curious to try the VG400 sensors from Vegetronix. Positives: consistent, do not corrode, and low power. Negatives: they’re expensive. There are a couple of additional negative points which I discovered the hard way and aren’t anywhere on their website. I’ll discuss them later.

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