What is the maximum analog grove ports on a Pi and how to get there

Hi All,

Im trying to get 18 soil moisture sensors working off one Pi. So we are considering either of the following sensors although am leaning towards the capacitive version (first one):

The questions I have are:

  • can we have 18 grove ports on a single pi?
  • if so what’s the best way of achieving this? I assume I will need to stack some hats but what’s the fastest way to 18?


Looks like we don’t have so many Grove mouth expanders yet… Or something else. My recommendation is that you connect all VCC together, GND together, and then use 18 GPIO ports to collect data. Go transforming wire so quite appropriate.

Hiya Citric

Many thanks for your reply. Thats a great suggestion.

The only issue I have now is that I found some wording in the wiki for the capacitive moisture sensor where it references needing an A to D hat on a Pi to use these sensors? (Grove - Capacitive Moisture Sensor (Corrosion-Resistant) - Seeed Wiki)

Will the raw GPIO ports all handle the readings from these sensors?

Thx for your help.

No, we use these expansion boards with Grove ports to complete these cases for the cleanliness of the wiring when we write the wiki. You can directly connect to the GPIO port on the Raspberry Pi to read data, and the rest of the content can also be operated according to the wiki.