• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

CFAH2002A newbie


New member

I'm trying to connect my CFAH2002A-NGG-JP to a PIC16F84A and things aren't working out quite right. Here is what if going on.

When I try to initialize the LCD, if I place the device in 2-line mode with a blinking cursor and underlined, I see all 40 squares dark with the first two blinking dimly. I can tell they're blinking but it's not a real on/off look.

If I set the device to 1-line mode, turn the display off, then turn it on with a cursor, underlined and blinking, the cursor looks good and the bottom row isn't dark. The top row is.

I don't quite understand what is going on. I read the spec sheet but I didn't see anything about clearing a particular row.

I can write characters to the bottom row in 1-line mode They are very faint though or don't show up at all. An "H" looks like "| |".

I thought sending a 0x38, 0x0F and then 0x01 would give me a blank screen in 2-line mode in the "home" position.

Obviously I mis-read something. Did I break it?? Any help would be appreciated since I'm lost now. :(
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.


New member
Ok... I found the problem. I went digging through the forums some more and found what turned out to be the solution.

I had to initialize the LCD 3 times like the spec sheet said. :) Also, I read that =~ 1.0 V at Vo would good place to start testing at. Since I don't have a pot yet I made a small resistor network and with 1.4 V at Vo my problems went away.

I now have "Hello World" written on CFAH2002 and life is good.
I'll get a pot in the morning to clean up the wiring. The resistors look ugly.

Thanks all