Quick Question

Im working with an lcd display (128x64 glcd) and a pic 16f877

my desk is under the thermostat for the house, i noticed that when the thermostat clicks on or off, my lcd display goes blank and stays blank.

havnt checked to see if its the pic stopping or just the lcd shutting off.

my pic has bypass caps etc on and the circuit is powered with a regulated power supply.

any ideas how to stop this sort of thing happening??

Sounds like we're getting close to Halloween.


Edit: Maybe your power supply is turning off on an overvoltage. Try a battery, or else plugging it in a different wall socket.

Is the reset pin floating?

Hi Chris,

check if the thermostat arcs when switching on or off.

I used air data computers in harsh industrial environment with the LCD turning black when a 200KW motor was switched off with the computer and motor relay in the same switching cabinet.

After using an MU enclosure for the computer the issue was fixed.

May be a snubber circuit across the thermostat contacts will solve your problem.

Hans