LiquidCrystal Library and Hantronix LCD

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

i've bought an Hantronix 16216L-B display:

And tried this tutorial:

But the display only shows dark rectangles in the first line (all 5x8 Dots are enabled). I think i've wired it correctly.
Does anyone know what i'm doing wrong?

I'm using 4-bit mode. This is what my wiring looks like:

LCD RS   -> Arduino digital Pin 5
LCD R/W  -> Arduino digital Pin 6
LCD E    -> Arduino digital Pin 1
LCD D4   -> Arduino digital Pin 8
LCD D5   -> Arduino digital Pin 9
LCD D6   -> Arduino digital Pin 10
LCD D7   -> Arduino digital Pin 12
LCD V SS -> Arduino GND
LCD V DD -> Arduino 5 V
LCD V L  -> Arduino GND
LCD A       -> Arduino 3.3 V
LCD K       -> Arduino GND

And how i instantiated the object:

LiquidCrystal lcd(5, 6, 1, 8, 9, 10, 12);

thx sunny

2

Have you connected a potmeter for contrast adjustment?

3

no, i've connected it to ground. I've have connected an 100 ohm resistor between LCD V L and GND during tests. The contrast was lower. Is it bad, to just connect it to gnd?

thx sunny

4

no, i've connected it to ground. I've have connected an 100 ohm resistor between LCD V L and GND during tests. The contrast was lower. Is it bad, to just connect it to gnd?

I don't think connecting it to ground is a good idea. Vee (usually pin 3) needs a voltage between 0 and 5v, by connecting it to ground the contrast is at the end of the scale. You'd either get just black rectangles or a blank display. Use a 20k potmeter and connect it like this:

http://www.arduino.cc/playground/uploads/ScematicLcd/scematic_lcd.pdf

5

thank you very much! :slight_smile:

Vee (usually pin 3)

hm, is this VL on my LCD? It's pin 3... i think so.

by connecting it to ground the contrast is at the end of the scale. You'd either get just black rectangles or a blank display. Use a 20k potmeter

I will try this, when i arrive at home. I thought, contrast at the end of the scale means only the active "pixels" have max contrast.

thx for your help! sunny

6

Ok, i added an 22k potmeter. Now i can fade between unvisible an nearly good visible rectangles. ;o) No letters, same problem as before. :frowning:

7

You are using pin 1 for the enable-signal. Pin 1 is Rx on the serial/USB-port, so you may need to disconnect the serial/USB-cable to to prevent interference. I suggest you avoid using pin 0 and 1 if you have another free pin available.

8

thx! It seemed there were two problems. Now all works fine! :slight_smile: First problem, i resolded the LCD cable. I think there was a "cold" solding. And i switched from using pin 1.

Thank you all, this saved my weekend! ;o) sunny