Plant-water monitor

  
When the soil is moist, the LED glows. If the moisture falls below a certain predetermined level, the LED begins to flash. If there is still less moisture, the LED turns off. To calibrate, connect the battery and insert the probe into a container of dry soil. Set R1 to its maximum value then reduce that resistance until the LED begins to flash.
Plant-water monitor - schematic

The range over which the LED flashes before going out is adjusted using R2.




Leave Comment

characters left:

New Circuits

.