Character lcd problem

[sevag00]

Hi all. I'm doing the character lcd tutorial from the ladyada website. I have connected all the pins on the arduino and the logic, backlight and contrast all worked out fine. Anyway, i uploaded the sketch to the arduino and instead of appearing "hello world" on the lcd it displayed some weird characters.
Anybody have an idea what the problem is? I have also attached an image of the lcd.

[adafruit_support_rick]

Check you wiring. It looks like you may have some of the data lines mis-wired. Post a picture showing your wiring

[sevag00]

Here's an image of the connection


RS: pin# 7 EN: pin #8 DB4: 9 DB5: 10 DB6: 11 DB7: 12

[adafruit_support_bill]

How long are those jumpers? Shorter is better. Post a photo showing the soldering on the header.

[sevag00]

I think those wires are the longest of the bundle. Maybe 10 inches. Here's an image of the soldering.



I think i messed up the soldering. Right?

[adafruit_support_bill]

Looks like some cold solder joints there. Several look like they have not flowed well onto the solder pad. Use a clean-hot iron and re-touch any suspicious looking joints. They should be smooth and shiny and have a cross-section like the diagram below:

[adafruit_support_rick]

the third and fourth solder joints from the right look like they might be bridged.

[floresta]

I think i messed up the soldering. Right?

Yes. If you look at the binary representation of the ASCII codes for your characters you will find that they all have the same logic level on bit7 as on bit6 and they all have the same logic level on bit3 as on bit2.

When using the 4-bit interface with the LCD bits 7 and 3 use the wire labeled DB7 and bits 6 and 2 use the wire labeled DB6.

If you look at your photograph you will see that it is quite likely that the blobs of solder on DB7 and DB6 are shorted.

Don

[sevag00]

Yeah. I figured it out. It was faulty soldering. Now, It works fine. Thanks for the help everyone.