Adafruit STEMMA Soil Sensor - I2C Capacitive Moisture Sensor

Pimoroni

£6

Most low cost soil sensors are resistive style, where there's two prongs and the sensor measures the conductivity between the two. These work OK at first, but eventually start to oxidize because of the exposed metal. Even if they're gold plated! The resistivity measurement goes up and up, so you constantly have to re-calibrate your code. Also, resistive measurements don't always work in loose soil. This design is superior with a capacitive measurement. Capacitive measurements use only one probe, don't have any exposed metal, and don't introduce any DC currents into your plants. Adafruit use th

Pimoroni's own words, read from their page.

Buy from PimoroniPrice seen 2026-09-05. Affiliate link.

Where this comes from

The part other shops don't tell you. Three separate questions, kept separate on purpose, each with its source.

UK company
Registered at Companies House as PIMORONI LTD, number 07510759. Checked 2026-08-29.
Means the business is a British legal entity, not a British-sounding name owned elsewhere. It says nothing about where anything is made.
UK operations
Stated by the company: "moving into our (hopefully) forever home at Parkway Drive - our first building with a roof that didn't leak" — names a location but no site or process, so this corroborates uk_hq more than operations. Source.
Means people employed here, or premises they actually work from. We keep this separate from the company badge because a registered office can be an accountant's spare room, and a company can be registered in Britain while everything it does happens somewhere else. Where we have not looked, we say so rather than assuming.
British-owned
No majority shareholding traced outside the UK. Companies House.
Read from the register of people with significant control, following the chain of holding companies. It does not gate anything: a firm can be made here and owned elsewhere, and that is worth telling you rather than hiding.
Where it is made
The maker doesn't say, so neither do we.
This is about the individual product, not the company. A British firm can sell things made abroad, which is normal and not a criticism. We would rather tell you which is which than average them into a score.