On Mon, 26 Jan 1998 13:44:20 GMT, you wrote:

>Hi,
>
>I am using a 16x1 lcd display with a 16C71. The C71 has a maxim
>reset circuit (I think it is a 705, but can't remember exactly).
>
>If the power to the circuit is removed and then returned quickly,
>the display stops working. I guess this is because the 705 resets
>the PIC, but the supply doesn't go low enough to properly reset
>the LCD.
>
>Is there a way round this?
>
>Thanks for your help,
>
>
>Mike Watson
If the problem is that the LCD is locking up in such a way that the
normal initialisation procedure won't recover it, you could power the
LCD from a PIC pin to allow the power to be cycled. Alternatively, if
the reset chip has a standard CMOS output (rather than open-drain),
you could power the LCD from that, so power is cycled on a reset.
These displays only take a mA or two so there shoudn't be any loading
problems with either of the above.

First, though, check you are *exactly* following the LCD
initialisation procedure correctly - this is very important.
     ____                                                           ____
   _/ L_/  Mike Harrison / White Wing Logic / wwl@netcomuk.co.uk  _/ L_/
 _/ W_/  Hardware & Software design / PCB Design / Consultancy  _/ W_/
/_W_/  Industrial / Computer Peripherals / Hazardous Area      /_W_/