4X40 LCD Diagram

**chewy747** · 08-25-2004, 04:28 PM

on the diagram from http://skylab.org/~chugga/mpegbox/files/lcd.GIF

What does the line coming off the 100 mean? The one that comes off the center pin and goes to the bottom pin.

**henriktha** · 08-25-2004, 04:58 PM

It's a 100 Ohm pot ;-)

**chewy747** · 08-25-2004, 06:10 PM

Do I need to solder a wire from one side to the middle of the pot?

**GWRedDragon** · 08-26-2004, 12:57 AM

Do I need to solder a wire from one side to the middle of the pot?

er...

**Superduck** · 08-26-2004, 01:59 AM

I think there's a bit too much "pot" going around, if you know what I mean...

I found these links to be much more useful than that diagram. Two of the best tutorials (in my opinion) are:
IceHardware
and
this one

Hopefully one of those will explain it for you.

Whether you need a potentiometer will depend on whether you want to be able to adjust the backlight. You could wire in a switch to change between full power and half power for day/night use, or just use the pot to adjust it to a comfortable level. Either way, check the specs on your LCD. I found my LCD needed 4.4v, while one of the sites said straight 5v is okay. Had I wired it that way, I would have fried the backlight. Check and double-check your specs. I've even had two LCD's from the same manufacturer use different specs.

Good luck,

Kris