AnalogIn showing random values when it should show 0v
Topic last updated
11 Apr 2012, by
Adriano Lopes.
2 replies
ain,
AnalogIn,
voltage
Hello,
I've been using the mbed microcontroller for over 2 months, and since day one I keep getting random values in the AnalogIn when I don't a power source connected to a port.
I searched the forum for a solution and didn't find anything that helped me to resolve this problem.
To test this I'm using this short program:
#include "mbed.h"
AnalogIn ain(p20);
int main() {
while (1){
printf("ain = %f \r\n", ain.read());;
}
}
Do you know any way to resolve this?
Regards,
Adriano
Replies
It's not a problem, it's a feature, or better said, it's physics.
It's floating, so it's not going to measure "anything"....
Tie it to ground and it'll measure 0V. Right now, it's not actually connected to anything, so it's not 0V.
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Hello,
I've been using the mbed microcontroller for over 2 months, and since day one I keep getting random values in the AnalogIn when I don't a power source connected to a port.
I searched the forum for a solution and didn't find anything that helped me to resolve this problem.
To test this I'm using this short program:
#include "mbed.h" AnalogIn ain(p20); int main() { while (1){ printf("ain = %f \r\n", ain.read());; } }Do you know any way to resolve this?
Regards, Adriano