DB0-DB3 to ground

Hey so just a general question. i've got an LCD screen thats been in close proximity to poorly shielded motors on airsoft guns and lots of static. I have it setup so it uses the 6 pin setup (DB4-7 RS and E). Now some guides tell me I should leave the DB0-3 alone, and others tell me I should connect them to gnd to try and help get rid of the screen messing up.

Well, would it be helpful, I've only had the thing mess up on me (start throwing gibberish characters) like 2 times, and i just pull a screwdriver across the gnd and 5v for it and reset the thing. Though doing that, ill probably break it or the arduino it runs off of soon. So would going gnd do anything good, or is there anything else that could be done to help keep it from messing up?

It seems likely to me that high noise levels could cause the issues you are seeing.

I use this style screen extensively. When I breadboard a new project, I leave those pins floating. However, when I finalize it, I ground them. It's pretty easy to drag solder across them and stick a wire in to pull the whole blob to ground.

I have never had any problems, though, so I cannot confirm this will fix it for you. It is best practice to leave them not floating, and in this case, that means grounded.

Nikarus: i just pull a screwdriver across the gnd and 5v for it and reset the thing.

That's called "creating a short circuit." Most circuits are intentionally design to prevent that from ever happening, and you are doing it on purpose? Continue that practice and eventually you'll have a failure. In fact, even if you stop now you'll probably have a failure eventually because you are certainly damaging something. Not everything that is damaged fails immediately...

Did you also hear the sound of "USB device unplugged" on your computer when you stick the screwdrive at the 5V and gnd? Like James said, it's intentionally destroying your investment. I had short circuited a few things in the past and they all ended up in the dumpster.

liudr: Did you also hear the sound of "USB device unplugged" on your computer when you stick the screwdrive at the 5V and gnd? Like James said, it's intentionally destroying your investment. I had short circuited a few things in the past and they all ended up in the dumpster.

No infact it doesnt, In operation I'm nowhere near a computer since this is built into somethign for airsoft. and btw the screen works fine now.

But the screwdriver in question, Before everyone jumps to "your a dumbass" conclusions. From 1 face of the blade to the other is over 900 ohms. Its got this blueish coating on it, that according to my grandfather (used to run a TV/Radio shop back in the 50s and 60s) was put onto it for working with electronics and trying to maintain safety of not damaging things via short circuit in case you were working, you moved your hand wrong and touched 2 pins or something. But the thing still has makes good contact so in cases when you need to jump from 1 spot to another to see if something will get continuity it'll still make the jump.

Actually its fairly nifty of a concept. So in cases where I want to test a switch without having to grab an actual switch and a resistor, I can just use the driver to make the continuity and it also has the resistance built into it to protect from high current. Also it makes a great demo potentiometer because from the tip of the driver up to where it goes into the handle it gets ~ 20k ohms.

Yeha ill probably still break the screen or something in the future, but itll probably be more of a physical, got shot by airsoft BBs at closerange and the glass broke, failure and not an electronic. Which also leads to, its not that big of a deal if the thing breaks electronically because odds are im gonna break the thing physically first.

But w/e, thing works now, havent managed to get interference on the thing since tying the 4 pins I asked about to ground. So I'm jsut gonna do that in the future.

And yeah sorry for necroposting, havent been on in a couple weeks cause of schoolwork.

Thanks for the additional information. I just assumed it was a regular screw driver. Hope the shaft is also coated with the same material and it doesn't easily wear off from regular use with screws :)

From 1 face of the blade to the other is over 900 ohms.

So you are saying that putting a load of 900R across a power supply is enough to reset it. Please think again, according to you this is putting a load of 5mA across your supply. This is not enough to affect any power supply, it is not enough to reset a device. I will stick with the dumbass conclusions and suggest that you measure that screwdriver again.