LCD with 16pins instead of 14pins?

[alank2]

I bought some 40x2 displays off ebay.  One says HD44100FS on it and the other says uc-40207 on them.  Both have 16 pins instead of 14 pins, but the 15/16 are NOT connected to the lcd backlight.  They might be pretty old.  Was there a different pinout before the 14pin one?  Both are samsung displays.  One says TM402CQ on the pcb.  Any ideas?

[macboy]

You may need to trace the pins back to the controller IC to reverse engineer the pinout for yourself.

[nixfu]

15/16 are usually for the back-light, I have never seen them used for anything else.

[Skimask]

40x2 sometimes have a 2nd enable pin.  1 enable gets the first 20x2, 2nd enable gets the last 20x2.

[Pjotr]

Pins 1 - 14 are pretty standard. Pins 15/16 are for the back light, whether or not there is a LED back light mounted. However the polarity of pins 15/16 varies from LCD to LCD and can sometimes be jumpered for correct polarity.