### Author Topic: Newhaven Display Problems  (Read 160 times)

#### barryflash2727

• Newbie
• Posts: 1
• Karma: 0
##### Newhaven Display Problems
« on: September 27, 2018, 12:23:01 AM »
I am a newbe who is attempting to interface with a LCD for the first time. I ordered three Newhaven 2 x 16 displays, part number NHD-0216BZ-FL-YBW.

I am having some trouble getting the thing to display anything. I was told by a Newhaven engineer that if contrast is set correctly that it will light up the first line when power and ground are connected.

I connected the first one according to the pin lables on the board. it flashed some crazy gunk on the display and then went quiet, never to twitch again. I then noticed that the pin marking do not match the data sheet. Upon contacting Newhaven, I was told that the data sheet was correct and to disregard circuit board labeling.

The data sheet calls for a 10~20K variable resistor. I don't have a variable resistor in the shop so connected several resisters and series. I connected the contrast pin to ground throuh 20K of resistors... no display. I connected it to ground through 10K of resistors... no display. I tried it at resistance levels between 10 and 20 K with no display. Any suggestions will be appreciated

I assume that 10~20K, as indicated in the data sheet means a pot with minimum resistance of 10K and maximum resitance of 20K, is this correct?

#### Ted_M

• Jr. Member
• Posts: 54
• Karma: 3
##### Re: Newhaven Display Problems
« Reply #1 on: September 27, 2018, 09:20:57 AM »
The Vo contrast pin 3 will need approximately +0.5V to get you in the ballpark to set the contrast level.
It would be best to connect the resistor to the VDD power supply in order to provide voltage to this pin.

A variable resistor is recommended as this makes it possible to adjust the contrast level with the desired visual setting. Then you may replace the variable resistor with a fixed resistance equal to the value set by the variable resistor.  A variable resistor with a minimum of 10K and maximum of 20k will work to get the voltage supplied to the contrast pin 3 set to approximately +0.5V for optimal contrast.

The circuit board labeling the pin-outs should also match the datasheet as published on our website.  If this is not the case, please send us a picture of the display.

Please let us know if you have any questions.

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