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Unread 30-01-2005, 00:37
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Re: Hall Sensor working?

Quote:
Originally Posted by Thadanator
Yeah, i'm having big problems too.
They are analog ins. I cannot get them to output usable data.
no matter where they are when I start the program, they just float around 0 and 1. Sometimes the value starts at like 50, then every second it drops by like 1 or 2.
but if i move the sensor, it goes back to 0, and once it's at 0, i cant get it any higher than 1.
No, they produce digital signals. But the signals are just a transistor switched to ground, so unless there is a pullup to +5 volts, you will read either an essentially random (and decaying) voltage or ground on the RC analog inputs.

The RC digital inputs provide a +5 pullup resistor, so they're all ready to handle the Allegro gear tooth sensor with no additional components. (The application note strongly suggests filters on the supply and the output, but you can ignore them if you're not concerned about electrical noise.)