which is a man-figure made out of wire and componants,
that has it's feet in a plants' soil, and it's head glows when the plant needs water.
the idea is to make a plant-watering-indicator that costs very little money..
this one consists of +- 5 components : a battery, 2 resistors, 1 transistor, an LED, and wires..
which means MAX MAX MAX of 1.5$. (if every components is 1 shekel..)
it works on simplified TTL NOT gate:
\\\ if 'moisture' (current between probes) < 'threshold' (set by resistors' values)
\\\ then LED=glow.
the sketches + schematics!:
the alien in position:
i will build it again, with a new battery (this one is already finished from all the games..), and capsulate it in an transparent capsule - open-source proper. then it really will look more HUMAN.