Wiring HD44780 OLED Display

[Format _C:]

I know there are diagrams everywhere on the net and even this site but I never wired a OLED display before. the only pin function that I don't understand is Pin three VBT Operating Voltage for LCD Brightness ADJ. I was thinking about getting http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=250364375631&Category=26206

Or a 20 X 4 Display (In regular HD44780 display wiring do I really need a contrast pot?)

Thanks

 

[theshadow27]

The contrast adjust is an input voltage between V+ (5v) and GND that tells the controller IC what the duty cycle on it's PWM output should be (on VFDs it was the grid voltage, it's function has been preserved since then). If left disconnected it may or may not display something onscreen, but it won't hurt anything. I'd suggest not connecting it, and if nothing shows up, tie it to V+ and see what happens (it should go full contrast).

The contrast pot it just an adjustable voltage divider