LCD (4bit) and appearing odd charactors

Forum 2005-2010 (read only) Software Syntax & Programs
1

I am having a problem which I can not get resolved. This is my first run around with the LCD in version 17. I have not had this problem until this. I am using a 16x2 LCD and the second character is always goofed up with something not quite human. Also, in the #9 position (8 if starting from 0) Always puts up a lower case letter. I have tried feeding a variety of letters and numbers trying to see if there was some sense to the goofiness, but there does not seem to be any good pattern. Prior to this, I was using version 15 which did not have this problem (but it did have other issues do to my own goofs, but that's another story).

Now for more oddness. If I send a string to the LCD in setup it displays fine.

Any ideas?

2

Now for more oddness. If I send a string to the LCD in setup it displays fine.

This statement implies that the characters mentioned in the previous paragraph were sent in loop(). If that is the case my question is "why would you do this?"

Your problem would be easier to diagnose if you:
(1) Posted your code
(2) Indicated the connections between your Arduino and your LCD
(3) Gave specific examples of the characters sent and the characters displayed.

Don

3

While waiting for a reply, I was messing with this more. It turns out I had a serial print in my PWM instructions even though I had comment all the other serial info. All it was was a note to myself that when the LED reached full brightness, it would say LED up.

void setup(){
lcd.begin(2, 16); // (rows, cols)
pinMode(beepPin, OUTPUT);
pinMode(ledPin, OUTPUT);
//Serial.begin(9600);

lcd.clear();
digitalWrite(ledPin, HIGH);
//beep();

lcd.print( "ABCDEFGHIJKLMNOP" );
lcd.setCursor (0,1); // Line 2 (col, row)
lcd.print( "0123456789abcdef" );

fadeIn();
delay(1500);
digitalWrite(ledPin, LOW);
lcd.clear();
//beep();
}

void loop(){
lcd.clear();
currentVal = analogRead( butSys ); // read the value from the sensor
reportMe();
delay(1000);

So my best guess is that once I reached the loop the serial was spitting out it's stuff and somehow getting mixed in with the LCD commands. Since I commented out this last line of serial in the fadeIn () all was well.

To answer your question as to why... This is a test script to make sure that everything is hooked up correctly. It gives me full text in all characters in set up, it beeps my beeper, it then looks at my sensors and spits out the input from them to make sure they are all sensing. It was readable but with an annoying glitch in the middle of it.

Your other question was what was I seeing. It was not standard text. It was more like a deformed E with crap and buckshot all through it. Not at all normal.