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Topic: Analog input problem (Read 1 time) previous topic - next topic

Hi, my Arduino Duemilanove analog input is returning numbers around 400 without anything turned on. What do you thing about it? Can it be problem of Arduino?

Thanks!!

retrolefty


Hi, my Arduino Duemilanove analog input is returning numbers around 400 without anything turned on. What do you thing about it? Can it be problem of Arduino?

Thanks!!


A analog input pin with nothing wired to it will have a 'floating input pin' condition and will give random/noisy/meaningless values if read from. If you want to test a analog input pin first wire to a ground pin and perform a analogRead and see the value returned, then wire the pin to 5V pin and test again and see the reading.

Lefty

JimboZA

As I write this, my Arduino web server is publishing the values of analog pins 2-5. Only pin 5 is actually measuring anything, and is varying according to a sensor. Pins 2, 3 and 4 are floating: as you'll see if you click the link, not only do they change, they're quite different to each other.
"Could you do the egg bacon spam and sausage without the spam then? "

No PMs for help please.
DO NOT power servos from Arduino 5V: give them their own power and connect the grounds.

Thanks so much retrolefty and JimboZA!!! Now, it's working.

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