LCD PC1602 16X2 display giberish

Projects Programming
1

Yes, I know this issue is not new, but I am still having the problem, and would like to have some help, if possible.
I just connected a PC1602 LCD to Mega (as well as to Duelmilanove),, but I can not get it to show the text I am sending to it, and I read instead gibberish.
The connection and program are very basic:
LiquidCrystal lcd(7, 6, 5, 4, 3, 2); //Corresponding to LCD pins (rs, enable, d4, d5, d6, d7)
void setup() {
lcd.begin(16, 2);
lcd.print("hello, world!"); }
void loop() {
lcd.setCursor(0, 1);
lcd.print(millis()/1000); }

I used both USB and external PS, the voltage is kept stable at 4.85V (no noticeable noise)
To test, I used the built-in Arduino LCD example ("Hello Word" and timer)
The LCD is alive and active but showing gibberish (on right time, correct character positions).
I doubled checked the connections to make sure I did not mix up the lines, checked voltages and scoped the lines. All seems OK.
I have googled long and most issues I have found have to do with long lines, noise or low PS, but in my case, the showed characters are not randoms: They repeat exactly, which does not make sense with (random) noise.
What could be wrong? any idea? Is there any setting for characters set for LCD?
thanks.

2

You say that the gibberish that you see is consistent. What do you see on the LCD where hello, world! should be ?

3

Thanks UKHeliBob for the support.
While trying to read and copy the gibberish as you suggested, I found the problem as follows:

In my case, I use 2 digital pins to supply +5V and GND to the LCD (out of convenience only).

Unfortunately, in my setup I placed those two digital command lines after the lcd initialization, which means the LCD could not read the initialization command, and thus failed.
BY changing the order, I now get the correct text (another problem is the contrast, which for some odd reason requires negative voltage ....).
Thanks again
samtal