Do a simple test, change your program to make all lines down to the LCD and free zes that way in an infinite loop or something, except the Data 6 pin, then using a micro/milliampermeter short circuit that pin to ground and measure the current. A low level at the /CE LCD pin would make it almost disconnected from the bus, only the internal "pullup resistors" would be active. Make sure no other device is selected and d riving the Data 6 pin, for sure without your consentment.... :) Wagner Lipnharski. dave vanhorn wrote: > > >> There may be some hardware fault, but I'm trying to make sure that it OUGHT > >> to work, before I start hacking up our one and only proto. > > > >Are you sure the LCD pin #1 (ground) has the same ground > >from the processor? > > Yes, solid connection. I'm having trouble talking to other devices while > the LCD is supposed to be sleeping. > Data 6 seems to be pulling hard high from somewhere. Since the LCD works, > it is my most likely culprit. > This pin is "data" to three other devices, and I can't talk to them. > > >The pull up is around 60k Ohms, it draws 73uA to drop a data pin to around > 0.5Vdc. > > One would think that a micro ought to be able to yank such a pin to ground > :) In fact the adjacent pin (data 7) is used in the same manner, as clock > for the other devices, with no problem.