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Topic: 16x4 LCD display issues (Read 2601 times) previous topic - next topic


Feb 17, 2012, 11:42 am Last Edit: Feb 17, 2012, 05:36 pm by Tris_C Reason: 1

I am hoping to use a 16x4 lcd display to show the battery voltage of a car battery as well as displaying the number of turns or rope on a which drum for my university project. However before i start going into the more complicated side i have decided to check that i can get the LCD display to work and check that it is compatable with the Arduino board.

The lcd display that i have got is - http://uk.farnell.com/midas/mc41605a6w-spr/lcd-4x16-stn-reflective-5mm/dp/2063247

i have wired it up as shown in the "Hello World!" example and have tried to upload this code to the board to check that everything is working correctly.

The code i have uploaded is -
Code: [Select]
#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup(){
 lcd.begin(16, 4);
 lcd.print("hello World");

void loop(){
 lcd.setCursor(0, 1);

the issues that i have got is that the LCD display is not showing anything at all, like it is still switched of, is it becasue this LCD module is not compatible with the Arduino board or becasue i have got the coding wrong?

Many thanks



How about a different link to your display.  Your present one requires me to sign into "Windows Live" which I don't intend to do.

The odds are that your display is compatible with the Liquid Crystal library and your sketch is correct since it is the one used in most tutorials. That leaves either a bad display or a problem with your wiring.  You did connect LCD pin 5 to ground didn't you.

I suggest you remove all of your wires and start over with the Adafruit tutorial at http://www.ladyada.net/learn/lcd/charlcd.html.  Part way through there is a photo showing a single row of blocks on the display.  Your display should have two rows, 1 and 3.  You must get that part working before continuing on to connect your Arduino.

Once you get your display working be aware that the cursor positioning will be offset on rows 3 and 4 due to a deficiency in the LiquidCrystal library.



I have changed the link - thanks for making me aware of it.... for some reason when i coppied the link from the Uni email it decided to try and route the hyperlink through webmail.

Pin 5 was connected to ground, i have started again using the link to the tutorial that you have given me, I can get rows of blocks coming up now but i have a feeling that the LCD display is goosed! half of the blocks came up but they were not full blocks, and halfway along the row the blocks were not responding.

Time for a new module i think!


... and halfway along the row the blocks were not responding.

There was another one like that a few days ago: http://arduino.cc/forum/index.php/topic,92201.msg692676.html#msg692676



So provide a picture of the LCD pins so we can see if they have some solder bridges.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter


So provide a picture of the LCD pins so we can see if they have some solder bridges.

It's worth a try but I still don't think that solder bridges were the problem in that other thread.  I think his pressure on the display 'fixed' it, at least for a while.


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