Outside looking glass Jinx - to go with my sprinkler controller. Yes the shorted PCB board not a problem an Oscillator and a= Schmitt trigger, I just wanted to be different and possibly novel hence= the Piezo idea. I'd wondered about a dew sensor, wasn't too sure if dew and water= were quite the same thing as far as the sensor was concerned. But thanks for the suggestions - I see I can buy a ready made car= rain sensor from Bosch at $900 odd according to RS. And I thought this would be so simple! colin -- cdb, bodgy1@optusnet.com.au on 03/11/2002 -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads