This is my first post in these forums, and I can guarantee that it will not be my last!
I found an LCD at work to try and interface with using my new Arduino UNO. I've been doing programming for a while now and wanted to expand into interfacing with electronics and data.
In this first lcd test, I'm having trouble getting the circuit built effectively. I wired the circuit into my breadboard according to a http://arduino.cc/en/Tutorial/LiquidCrystalBlink on this website. The last wire that I placed in my breadboard was the 5V lead to go to the Logic Voltage pin on my LCD. When I plug the 5V into the power rail, the Arduinos onboard LEDs (on lamp and d-pin 13 lamp) fade off until the wire is removed.
Can anyone tell me what's going on and how I would go about fixing this? I'm going to try and rewire it again in the meantime.
It sounds like either you are not wiring it up correctly or you have a differeant sort of LCD display.
Do you have any resistor in the backlight circuit, you need one.
Do not wire anything up with the power still on, that is a way to blow up your chips.
I am assuming that your LCD module resembles the one in the picture on your link page. Almost all of them follow the same pinout but there are a few that are slightly different.
Can you provide us with any information about your display? A manufacturer's name and/or part number would help as would nice sharp pictures of both sides of the module,
Otherwise here are some suggestions. First remove all of the wires between your display and your Arduino. Next you want to connect up only the power pins and the contrast potentiometer (LCD pins 1, 2, and 3). When you apply power to the LCD module your Arduino LEDs should remain on and the ICs on your LCD should remain cool. If you have the same type of problems that you had before then you may either have a bad device or possibly one of the oddball displays with the power pins reversed. If that is the case then try reversing the connections to pins 1 and 2.
If your LCD has an LED backlight you should deal with this next. It's power leads are typically a mirror image of the main power leads which means you should connect pin 16 (the one nearest the center of the display if there are no markings) tp GND and connect pin 15 to +5v through a 150 ohm resistor. Your backlight should come on although it may be dim. If your LCD has pins 1 and 2 reversed then these pins may be reversed as well.
Next you have to adjust the contrast potentiometer. At one end the display should be blank and near the other end you should see one line of blocks (assuming a two line display). Adjust the potentiometer until the row of blocks is barely visible.
Now you can connect the six wires between your LCD and your Arduino, connect LCD pin 5 to GND, and continue with the example program.