Help - In lcd "Larger Character 20X4 204 2004"

Other Hardware Displays
1

Hello Friends :wink:

I need help..

I bought the "Larger Character 20X4 204 2004" not the regular small LCD.

From: http://www.ebay.com/itm/Larger-Character-20X4-204-2004-LCD-Module-Display-Screen-LCM-White-on-Blue-/200456734645?

and I2c module here : http://www.ebay.com/itm/291043911498?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The i2c adress is : 0x27.

This LCD has 18 pins instade of the regular LCD that has 16 pins..

  1. Why?

  2. I try to drive this lcd with the same code that run the small LCD ...but the screen doesnt show anything...

How i can drive this module?

The connections are to be different? The libery maybe? ( I use i2c liquidcrytal LCD).

Thank You All !

:slight_smile:

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2

Pins 17 and 18 are not used.

Your I2C "backpack" should be mounted to pins 1 to 16. Pin 1 is denoted by a square pad when the others are round.

Backpack connections must be soldered - either directly to the display, or pin headers and sockets soldered on and plugged together.

If you connect power only to the assembly, the backlight will probably not light up, but you should be able to adjust the contrast potentiometer until a row of "blocks" show up on the first (and third, I think) lines. You must be able to see the blocks before you can do anything else.

When you can see the blocks, you need to use the "I2Cguesser" sketch to determine the correct constructor. Or have you already got this same backpack working with a small display? I daresay we need to know that.

You do need to explain what you do and do not get - is the backlight lighting up? Do you get the blocks?

3

Many Thanks for your kindly answer!

i didnt solider it yet...

but lights are on...block i didnt see...

i just want to make shure this display need to work the same as lcd QC2004A

so now i will solider and update here :slight_smile:

4

OK THANK YOU !!! IT WORKS !!! :slight_smile:

What help me is what you say about line 1 and 3 that needed to be seen after the connection..

I change the resistor untill i saw the lines...

but it wired to see the lines i change the resistor to the left side until it stopped...normally the optimal it when the resistor on the middle.

Again Thank you !

5

tomeryehu:
normally the optimal it when the resistor on the middle.

Rather unusual - normally the potentiometer has to be set close to the ground end.