http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. Thu, 20 Nov 2008 22:30:55 -0800 http://backend.userland.com/rss092 hey just a curious question, does a -ve 5v at the microcontroller pin do any damage to it?? im using a zero crossing detector as an interrupt & im <noauthor@nospam.com> http://www.8051projects.net/forum-t9535.html Dear Ved, use a diode to get the +ve half for zero crossing detection.Controller pins, in general, are meant to operate in the positive side with resp Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t9535.html k thnx dude, simple solution i knw, just found out an hr back tht the -ve voltage causes damage.... Ved<vedvern@nospam.com> http://www.8051projects.net/forum-t9535.html