Code that worked with WINDSTAR LCD doesn't work with Newhaven LCD?

**Byte_Butcher** · - 14th April 2010, 22:30

Are you SURE you have the pinout correct on the New Haven display? It MAY not be the same as the windstar...

I know nothing of Windstar, but I use quite a few Lumex displays, and have recently started using some New Haven displays, and the pinout on the NewHaven that I'm using is NOT the same as the Lumex.

Lumex :

Pin1 = Ground
Pin2 = Vdd
Pin3 = Contrast adjust

New Haven:

Pin1 = Ground
Pin2 = Contrast adjust
Pin3 = Vdd

All other pins are the same except for 2 & 3 being swapped between NewHaven and Lumex.
Can't vouch for the Windstar, but you might want to have a look at the data sheets again?

Steve

**Darrel Taylor** · - 14th April 2010, 23:10

Originally Posted by Byte_Butcher

... and the pinout on the NewHaven that I'm using is NOT the same ...

Awesome!
Didn't see that coming, and I was looking at the datasheet, which agrees with you.

Easy enough to test.
Jellis, If you turn the contrast pot the other way, does it start smoking?

OK, probably not the best way to test it.

Add: Probably wouldn't anyway's, rats.
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malc-c · - 14th April 2010, 23:23

I had a similar issue with a 16 x 2 LCD, which turned out required a voltage range between -5v and +5, and seemed to offer the ideal contrast when the voltage was around -3.5v

Not saying this is the cause (haven't looked at the datasheet for your display), but it did catch me out.

**Byte_Butcher** · - 15th April 2010, 00:23

When I bought my Newhaven displays, the pinout difference stood out immediately to me in the data sheet.
On the Lumex, and all other displays I've used, the Vss, Contrast, and Vdd pins are laid out in a row with the contrast in the middle like the pins on a pot usually are, with a voltage across the "outer" legs and the wiper in the middle.

The out of sequence power / contrast / ground sequence caught my eye right off.

Sorry I didn't mention it sooner. I didn't think about it until the word "Newhaven" came up again in one of the later posts and sparked a brain cell....

I hope that's the problem for Jellis00 !

Steve

**jellis00** · - 15th April 2010, 01:59

Originally Posted by Byte_Butcher

The out of sequence power / contrast / ground sequence caught my eye right off.

Sorry I didn't mention it sooner. I didn't think about it until the word "Newhaven" came up again in one of the later posts and sparked a brain cell....

I hope that's the problem for Jellis00 !

Unfortunately not, Steve.
Here is data right out of the data sheet for my display and Contrast Vo is in the right plac:.
Pin No. Symbol Function Description
1 Vss Power Supply Ground
2 VDD Power Supply Supply voltage for logic (+3.3V)
3 V0 Power Supply Power supply for contrast (approx. 0.3V)

My MCU interface to the Newhave LCD is correct with their data sheet and is shown in attached image. Still looking for the problem.