I am using an arduino mega which controls my home entertainment system but i am getting lots and lots of false triggering!
The setup is like this: a reed sensor is connected one end to a 5v source and the other end to my arduino(and also to the ground with a pull down resistor). When the sensor is triggered with a magnet. The arduino is recieving 5v(HIGH) and then it triggers my x10 module that controls my home entertainment system(beamer,surround,lights,heating,..) and also it powers a transistor so a part of my table slides apart(allowing the beamer to porject on the wall behind it). From the beginning i have noticed strange things, like things that were lying on the table when I left now were next to it. This was an indication the table half had been moving while I was not around. Now I have installed a datalogger on my x10 system and guess what: The arduino triggers more than 10 times a day unwanted!! At first I thought it was a faulty reed sensor so i replaced it with a fysical button. Same result,arduino seems to trigger randomly Also the fact that the home entertainment system turns back off instantly after being enabled suggest the arduino must get some faulty pulses from somewhere... Then I was thinking the cause was that the arduino was connected to my mac mini and everytime the com port closes the arduino resets. Turned out it wasn't the either.
the setup is:
A 12v power supply feeds the motors to my table and drawers. Also on that 12v are multiple 7805's for the 5v feed like arduino and sensors.
Anybody who has an idea what could cause this. It is really bad for my beamer to be turned on and off instantly 10 times a day
PS excuse my bad English, it is not my native language