Best way to clear display on shutdown

rhaguiuda · Joined: 05 Sep 2007 Posts: 46 Location: Londrina - Brazil

Hi

My application has a 7-seg LED display and an ADC. The displays shows the result of ADC conversion.

When I cut the power (turn off the system), for a short time the display shows some garbage (system still remains powered for some time by filters capacitors, but due the voltage drop the system gets corrupted ADC data).

I'd like to detect when the power is down and clear all displays, so no garbage is displayed.

Which is the best way to do that? (thought using comparator generating interrupt, if voltage gets below 4V for example...).

Thanks

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

1. Post the manufacturer and part number of the display.

2. Post your PIC.

3. Post a link to a schematic of the PIC and the segment driver circuit (or describe it).

Your basic question about how to detect an impending power failure,
has been discussed in the forum archives. But the specifics of how
to disable your display will require the information requested above.