A flashing LED signals the necessity to water a plant
Very low current consumption - 3V powered circuit. This circuit is intended to signal when a plant is needing water. A LED flashes at a low rate when the ground in the flower-pot is too dry, turning off when the moisture level is increasing. Adjusting R2 will allow to adapt the sensitivity of the circuit to different grounds, pots and probe types.
This little gadget encountered a long lasting success amongst electronics enthusiasts since its first appearance on this website in 1999. Nevertheless, in the correspondence exchanged during all these years with many amateurs, some suggestions and also cr