Newhaven 4x40 LCD, issues!

[MOUNTAIN747]

Christopher, pin 3 is DB5, pin 16 is NC. If you have a 20k pot center taped to Vo you should have contrast. I can vary the contrast on my 4x40 over about a turn and a half of the pot. It goes from almost no visible characters to bright characters. Look over your Vo hardware once more.

Wayne

[Christopher4187]

Christopher, pin 3 is DB5, pin 16 is NC. If you have a 20k pot center taped to Vo you should have contrast. I can vary the contrast on my 4x40 over about a turn and a half of the pot. It goes from almost no visible characters to bright characters. Look over your Vo hardware once more.

Wayne

You have an LCD screen. I have an OLED screen ( I know I put LCD above but it was a mistake). Pin 3 for me is no connection. Putting a POT on pin 3 does nothing. Again, this board does not have a Vo pin.

I suppose you could adjust the contrast by lowering the input voltage if it's really necessary.

[MOUNTAIN747]

Wow, I totality missed that. My apologies, I was a bit too energetic to help and failed to read your first post closely. Glad you got the OLED working. It's a good looking display!

[Christopher4187]

No worries. I'd prefer someone be too energetic to help than not help at all.

[jmgelba]

I have a Newhaven display here with the ST7066U driver. It doesnt work, nor did its replacement. I then went to an Optrex and plugged it into my connector, and it worked right away. Coincidence? Either way, could you guys confirm that a ST7066U driver works?

Thanks.

[MOUNTAIN747]

Jmgelba,
Just a suggestion, try using the above Newheaven_4x40_Text Code.txt , INIT_LCD rutine and its sub’s, EEPRON, and E1 variable. This routine is for a duel ST7066U so you should only use Command1 in INIT_LCD. After initializing the LCD, all PBP commands should work. As stated in above post’s Vo adjustment must be made to find the sweet spot to display. Good luck!

Wayne