Questionable Pin Functioning
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Posts: 46,084
When pins fail, can they half-fail?
Here is my issue . . . I set up the Dallas CS-1302 this weekend,
and utilized the demo program provided by Parallax. That includes
three pins to the RTC and four pins for input switches.
When things didn't operate the way I expected I worked on debug.
When I was fairly sure the program was correct, I started messing
with the hardware. The problem ended up being pin 4 as an
input . . . it would stay low even when pulled up with a 10k to
5+.
I moved all four inputs to another port (port D, pins 12-15) and
everything works fine.
So, my question is now what's up with that pin? is it half fried?
As an experiment I set it up to drive an LED, it works when
tripped 'high' (pin high to 470 ohm to LED to ground), i.e., I can
turn the LED on and off. I did not try to inverse the output or
input, i.e., as output = 5+ to resistor to led to pin, and as input =
normally pulled low, 5+ to set input high, if that makes any sense).
TIA, John Remington.
Here is my issue . . . I set up the Dallas CS-1302 this weekend,
and utilized the demo program provided by Parallax. That includes
three pins to the RTC and four pins for input switches.
When things didn't operate the way I expected I worked on debug.
When I was fairly sure the program was correct, I started messing
with the hardware. The problem ended up being pin 4 as an
input . . . it would stay low even when pulled up with a 10k to
5+.
I moved all four inputs to another port (port D, pins 12-15) and
everything works fine.
So, my question is now what's up with that pin? is it half fried?
As an experiment I set it up to drive an LED, it works when
tripped 'high' (pin high to 470 ohm to LED to ground), i.e., I can
turn the LED on and off. I did not try to inverse the output or
input, i.e., as output = 5+ to resistor to led to pin, and as input =
normally pulled low, 5+ to set input high, if that makes any sense).
TIA, John Remington.