swap lcd 16x2 with 20x2

[kzeoprf]

Hi I am new in this forum, and I want to ask a question concerning the swapping of the two lcds. It seems in this forum there is great experiance in LCDs. Is it possible without changing nothing (swap lcd 16x2 with 20x2)? I have a situation where the 16x2 (lcd1602 blue backlight) is working ok but when I use the 20x2(rt2002a2 blu backlight) it does not. If I connect all the pins on the 20x2 I get in the the straight line but in very week black color. No messages -data. If I disconect RW or/and EN then I get the straight line white OK but no messages. I use starnded hook up wire to connect the LCD with the PIC. Do you have any clue what to do. The fact is that I have a delevirable and last moment I have to use biger display and it does not work.
Any help is welcome. Is there any chance the LCD to be out of order? I am waiting for a new one.

[Ioannis]

1. Maybe the new LCD is slower so it needs more start up time. Look for the LCD_COMMAND and LCD_DATAUS DEFINE's.

2. What about the contrast setting ofthe LCD?

Ioannis

[kzeoprf]

Thanks for the reply. I tried this is the same. The strange think is that when I connect the enable or RW the line goes weak black from white.

[Archangel]

Hi I am new in this forum, and I want to ask a question concerning the swapping of the two lcds. It seems in this forum there is great experiance in LCDs. Is it possible without changing nothing (swap lcd 16x2 with 20x2)? I have a situation where the 16x2 (lcd1602 blue backlight) is working ok but when I use the 20x2(rt2002a2 blu backlight) it does not. If I connect all the pins on the 20x2 I get in the the straight line but in very week black color. No messages -data. If I disconect RW or/and EN then I get the straight line white OK but no messages. I use starnded hook up wire to connect the LCD with the PIC. Do you have any clue what to do. The fact is that I have a delevirable and last moment I have to use biger display and it does not work.
Any help is welcome. Is there any chance the LCD to be out of order? I am waiting for a new one.

I would check the pin out on the LCD maybe one of them is non standard, also make sure to bypass the power input pins with a smal cap. Some are a bit sensitive to noise, I found.

[kzeoprf]

I done that but the same think. The 20x 2 lcd was chosen due to they have the same controler and the same initialization sequense. I think do not have any options to wait the new lcd.