MLSMS Sensor

The multi-level soil moisture sensor consists of Chinese relay modules with FC-28 electrode. This threshold can be used to lower and raise the threshold at which the irrigation system can water according to the needs of specific plants. https://rae.agriculturejournals.cz/pdfs/rae/2025/01/04.pdf - many similar works on Chinese FC-28 modules. www.mdpi.com/1424-8220/24/18/5886 is a scientific article, FC-28 resistive sensor. Quotation...

Low-cost sensors had a maximum RMS error of 4.79% for resistive sensors.

If you are constantly energised with this terrible chemistry, the maximum service life is one and a half months.

In these projects, the electrode of the moisture sensor works only during irrigation, in the second version it works only with the irrigation schedule for soil dryness, that is, at least one season of reliable operation of the electrode (there are also electrodes coated with immersion gold).

Need to buy and do tests, check what the maximum time frame is! With wholesale prices of $0.1-0.2 and if you make them easily removable (they are removable, but at an angle - you NEED to order a straight version (plugged in, removed).

This is a wonderful cheap consumable!

The SCM unit can be upgraded, made on one board.

The MLSMS sensor itself, even if there are 10-20 electrodes, can also be upgraded, connecting to one relay module.