Blog
18 Nov 2010
This project is a plant watering watcher that is able to flash a LED at a low rate when the soil in the pot plant becomes too dry. The circuit uses a CMOS quad Schmitt and is powered from two AA batteries. Check schematic and PCB boards on the link below.
Plants watering watcher - [Link]
November 18th, 2010 at 4:37 pm
This project was stolen from http://www.redcircuits.com where it replaces an earlier version that did not work.
The IC is an ordinary CD4093 that has a minimum supply of 3.0V when the battery is new. But when the battery runs down a little then this IC will not work.
The project should use the 74HC132 IC instead (it has different pins) because its minimum supply is 2.0V.
I used the 74HC132 IC in my Plants Watering Watcher-2 project that is here.