Go Down

Topic: display not changing contrast dramatically depending on what is displayed (Read 612 times) previous topic - next topic

I am using https://www.sparkfun.com/products/9052 on an Arduino Uno, IDE 1.0.5 on Windows7.
When I try to write to the display, a string ending in punctuation will not work (LCD goes blank), but the same string without punctuation at the end works. Even if I just use another letter at the end, it works, and if I use a ":" it does not.
Luckily I can just exclude punctuation in this case, but this seems really strange so I was wondering: has anyone else seen this and has an idea what is going on?
Program is supposed to cycle between displaying "wait for it" and "hit"; when I end either string with punctuation LCD remains blank for that second. I included a line that will work, commented out, and one that does not.
Here is the code:
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup() {
 lcd.begin(16, 2);
}
void loop() {
  lcd.clear();  
 //lcd.print("wait for it"); // works
 lcd.print("wait for it."); //doesn't work  
 delay(1000);  
 lcd.clear();
 lcd.print("hit");
 delay(1000);
}


Update: it turns out the display isn't staying blank, but instead the contrast changes so dramatically between the "hit" and the "wait for it" that it looks like blank unless I up the contrast to the point where the "hit" is almost unreadable. What would cause that?


The power for both the backlight and the controller are connected to 3.3V. I am not sure what you mean by "rail", though...

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy