CircuitGeek

If you a gardening lover, you must be annoy that it is hard to tell, whether the ground of the flowerpot is running out of water or not.
However, with the help of this CMOS quad Schmitt, you can easily detect the flowerpot condition just in a second.

First, you need to have these components ready:

470k 0.33W [...]

This intercom circuit is based on LM386 low voltage audio amplifier. It uses 8 ohm speaker works as microphone and speaker at the same time. 10k potentiometer is used to control the volume. As a double pole double throw switch is used in this circuit it reverses the speaker’s position and makes one as loudspeaker [...]