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Topic: 1602a 16X2 LCD is blank (Read 7 times) previous topic - next topic

dhenry

Quote
The power busses at the top left corner of the picture ( red, orange, yellow and white wires ) are not connected to where you bring in the power at the top right of the picture (blue and white wires).


due to optical illusion. You can count the pins, from right to left, as the leds for sure  work so pin 15/16 are right.

floresta

Quote
due to optical illusion. You can count the pins, from right to left, as the leds for sure  work so pin 15/16 are right.


That is what I thought at first, except I thought there was a problem with the data lines going to the lower numbered Arduino pins.  We may have to specify photos shot from directly above with a long lens.

I didn't think there was a power problem since the backlight was working, until JoeO mentioned the power bus.  I looked at my breadboards, which don't have that gap in the pin connections, and they don't have the gap in the blue and red lines either.

Of course this problem would pop right up in step two of my three step procedure (or with a quick voltmeter check on the power pins).


Don

JoeO

Here is a link to one of my previous posts regarding bread boards and their power buses.  They are not what you may think.

http://arduino.cc/forum/index.php/topic,141319.msg1061791.html#msg1061791

vier

Hi all, this is my first post,my name is Francisco Javier; I am  from Menorca, spain, so sorry if my english sounds bad.
I am really new to arduino, but I got to run a LCD like this one.
Maybe I am telling a foolishness, but I have seen in the code you are using the pins 11 and 12 as data and not for Enable and RS. I am wrong or is it??
(12,11,5,4,3,2,1) instead of (5,4,3,2,1,12,11)


floresta

#14
Feb 02, 2013, 08:12 pm Last Edit: Feb 02, 2013, 08:15 pm by floresta Reason: 1
Quote
Maybe I am telling a foolishness, but I have seen in the code you are using the pins 11 and 12 as data and not for Enable and RS. I am wrong or is it??
(12,11,5,4,3,2,1) instead of (5,4,3,2,1,12,11)

You can use any available Arduino I/O pin to feed any of the LCD pins.  The values that you use in the LiquidCrystal.lcd() statement have to match your particular circuit connections.

They have very cleverly made it difficult to find the explanation for this. Here is how:
Start here: http://arduino.cc/en/Tutorial/LiquidCrystal
Scroll down to the bottom
Use the Liquid Crystal Library link to get here: http://arduino.cc/en/Reference/LiquidCrystal
Use the LiquidCrystal() link to get here: http://arduino.cc/en/Reference/LiquidCrystalConstructor
And there it is under 'Syntax'

Of course a simple comment would go a long way as well:

Code: [Select]

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);      // put your pin numbers here


Don




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