Im experiencing false triggers of digi switch inputs (on occasion) and not sure whats causing this. Im using a pic 18f, with interrupt driven switches on PortB. I have external 100k weak pull-ups (needed due to power constraints) and note that the voltage is held high at around 3.02V which is a fair ceiling above the high input min value of 1.7V.
Observations:
When touching negative terminal (only) of DVM to board ground, it triggers a false activation. This is quite repeatable. On occasion, when momentarily pulling another switch low , I see it affect the logic on another pin, but only on occasion. Ive put in 0.1uF caps on the DI pins, but this hasnt really helped. Any ideas whats causing this? Anything to do with interrupts and or switch bounce?
VDD
V
Input Low Voltage (Max)
V
Input High Voltage (Min)
V
Observations:
When touching negative terminal (only) of DVM to board ground, it triggers a false activation. This is quite repeatable. On occasion, when momentarily pulling another switch low , I see it affect the logic on another pin, but only on occasion. Ive put in 0.1uF caps on the DI pins, but this hasnt really helped. Any ideas whats causing this? Anything to do with interrupts and or switch bounce?
VDD
3.6
Input Low Voltage (Max)
0.54
Input High Voltage (Min)
1.7