LCD on/off

[skimask]

I have a wireless module wth an LCD. I want to save the batteries by turning off the LCD when not needed (the unit must continue functionning). I added a switch between the power and Vdd of the LCD. turns off ok, still get some very dim light back light. BUt when I turn it back on, I either get funny characters or black squares on the first line (2x16 lcd)
how would I go turning it back on with the proper data showing?

thnks
ken

You'll have to do an LCD reset. Add a 'FLAGS = 0' in your code with each LCD update, that should 'reboot' your LCD the first time you send characters to it after it's been turned back on. Your LCD has an MCU in it also and has to be initialized, just like a PIC. PBP does this for you (behind the scenes) as part of it's startup.
As far as turning it off, try moving the switch over to the ground...switch the ground in and out of the circuit and see what happens. Might take care of the dim backlight also.

[lerameur]

I put the switch on the ground. Thjis way the backlight is turned off but I can still see the characters. I put an ammeter to see how much current the lcd was taking, and to my surprise, the current is the same with or with a light LCD. So I guess powering down the lCD to save energy (battery life) is useless

k