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Topic: Simple Button Input Floating Problems - New User (Read 3 times) previous topic - next topic

Jack Christensen

#15
Apr 20, 2011, 11:46 pm Last Edit: Apr 20, 2011, 11:51 pm by J Christensen Reason: 1
No, I'm afraid I don't see.  If the switches are just sitting there, not being touched, not changing state, they will not bounce.  At least not any switch I've ever met.  Bouncing is a transient phenomenon that happens when a switch is switched.

Now, what you say may well be true, debounce logic may indeed fix the problem, but in this case it's addressing the symptom, not the underlying cause.  I'd rather understand why the signals are changing when the thing is just sitting there untouched.  If I understand the situation correctly, this is not normal switch behavior (but yes, bouncing is normal switch behavior).
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

bilbo

Yes you are correct that debouncing does not explain why the phenomenon is happening, but it will fix the problem, which seems good enough to solve the OP's woes...I would guess the problem is due to EM noise or an issue with the button you are using.
Alice asked the Chesire Cat, who was sitting in a tree, "What road do I take?"
The cat asked, "Where do you want to go?"
"I don't know," Ali

Jack Christensen

LOL, well I am just about ready to give up and call Mulder and Scully anyway.  This must be the Haunted Arduino.  Either that or there are a dozen arc welders in the next room!
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

bilbo

Not really, it could be an unstable USB supply, poor grounding....etc.
At least the phantom emails wont be bothering the OP anymore.
Alice asked the Chesire Cat, who was sitting in a tree, "What road do I take?"
The cat asked, "Where do you want to go?"
"I don't know," Ali

Jack Christensen

Yes, good points.  woodsby, any chance of taking the Arduino to a friend's house or something, to see if it exhibits the same behavior?

I do have a crazy EMI story.  Had a treadmill that didn't get along with my DSL internet connection.  Every time someone fired it up, my connection would go down, but once the treadmill was running at a more or less constant speed, things were OK.  Took quite a while to figure out the cause.  Once I did, I reran all the phone lines in the house with CAT5 cable, and even put it in EMT as much as possible, but to no avail.  When that treadmill was running, AM radios were unusable within a couple hundred feet of the house (and the treadmill was in the basement!)  Never did manage to mitigate it.  Luckily the treadmill died (kid on the cross country team did it in) and the replacement (different brand) doesn't bother the DSL.  Just saying, it could be something totally unrelated.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

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