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Author Topic: LCD randomly reverts to displaying hieroglyphs  (Read 2618 times)
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I don't think you connected the grounds, Dave.
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Your power supply probably has a transformer and maybe it is a switching type. If that is the case it could produce EMF
A power supply that doesn't produce EMF is a fairly useless thing.
Perhaps you meant "EMI"?
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Your power supply probably has a transformer and maybe it is a switching type. If that is the case it could produce EMF
A power supply that doesn't produce EMF is a fairly useless thing.
Perhaps you meant "EMI"?

  Sorry, I work with motors a lot and had EMF on the brain. I will correct my post.

Thanks,
Mark
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Characters move to the left. 1st line to 3rd and 2nd to 4th.
This is the normal 'shifting' (improperly called 'scrolling' in Arduinoese) pattern for a 20x4 LCD.  So your LCD controller appears to be functioning normally in response to rogue signals.  Sometimes the RS line is high resulting in the scrambling of the display data and sometimes it is low resulting in the shifting of the display and the appearance/disappearance of the cursor.  Everything points to noise produced by the top-off system.  Getting rid of the noise is another matter....

Don
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 Added magnetic chocke to 12v powerline.
 So far - so good.
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 ALright! Thanks for reporting back. I am curious. Did someone else finish this project just like how you did it without experiencing interference? You seem to have used some code from some online source.
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Now only manual switching of pumps troubles LCD.
Would shielded cable for LCD connection help ?
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Now only manual switching of pumps troubles LCD.
Would shielded cable for LCD connection help ?
Some careful planning is need if you decide to use the 80-wire hard drive cable. They are not shielded but every other wire is grounded to improve signal to noise ratio. You could also try aluminum foil to wrap around your current cable to see if it is enough help.
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One more update

Guys advised to twist all signal wires with ground. I will try where it is possible. LCD is connected via 8 wires and i dont know if it is good idea also using twist idea there ,or shielding is more advanced.
 I can only work with arduino when lights come down in tank and that's is damn hard. smiley-twist
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