Hi Joe, On Tue, Jun 21, 2011 at 1:04 AM, IVP wrote: > I've had LCDs do funny things when glitches get on the Enable > line. The last instance was the power line for a solenoid running > next to it. I've not noticed problems with over-long leads but that > might just be because most projects I do are pretty quiet. An RC > filter would be OK, as long as you meet the timing specs. LCD > timing errors are when intervals are too short, so some lengthening > won't do any harm. Even a stiffer pull-up than the LCD's on-board > one might do on its own I tried lengthening a number of areas, including the duration of the enable strobe, the interval between loading the bus and the enable strobe, and the interval between the two nybbles. None seems to have made a huge improvement, and in fact sometimes has caused more glitches. > Enable is the single most important line, as it is the only one that > controls data writing, which is why every other line can be multi- > plexed quite successfully. If you aren't seeing noise on the other > lines then Rs and Cs probably aren't necessary. It won't do any > harm to add filters, but it would be fairly unusual, and if possible > keep the cable away from any likely sources of noise, such as > relays, switching semis and so on Ok, that's good to know. Any suggestions for what to put on the enable line= ? Thanks! Josh --=20 A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. =A0 =A0 =A0 =A0 -Douglas Adams --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .