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Topic: Problems with analogRead (Read 612 times) previous topic - next topic

Hackaro

i'm noob with analogic electronics....

can anyone answer those questions?

why do i get large oscillation values from any analog port even though it isn't linked to any circuit'???

are there any diference between the analogRead and the voltimeter values????

thanks

nkcelectronics

If the analog in pin is not linked to any circuit, it is floating, which means it can read any value.  What is the purpose of reading the value from a pin that is connected to nothing?

Hackaro

oh it was just a test i made to see what value i got... and when a i saw that oscillation i was worried thinking my arduino is crashed or something like that

thanks for the explanation

Oracle

Quote
If the analog in pin is not linked to any circuit, it is floating, which means it can read any value.  What is the purpose of reading the value from a pin that is connected to nothing?


Isn't that an okay way to seed your random number generator? :)

spiffed

There are certainly entropy generators which use background noise as an entropy source (sadly the only one I can think of off the top of my head comes from sparkfun].

Many use only a few bits from the acquired signal though; IIRC this has something to do with Johnson noise being Gaussian.
iDuino - MaxSerial - [url=http://spi

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