/*
LiquidCrystal Library - Hello World
Demonstrates the use a 16x2 LCD display. The LiquidCrystal
library works with all LCD displays that are compatible with the
Hitachi HD44780 driver. There are many of them out there, and you
can usually tell them by the 16-pin interface.
This sketch prints "Hello World!" to the LCD
and shows the time.
The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* LCD VSS pin to ground
* LCD VCC pin to 5V
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)
Library originally added 18 Apr 2008
by David A. Mellis
library modified 5 Jul 2009
by Limor Fried (http://www.ladyada.net)
example added 9 Jul 2009
by Tom Igoe
modified 22 Nov 2010
by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/LiquidCrystal
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
}
void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis() / 1000);
}
I appreciate your help in getting my LCD to display text, I have tried to watch tutorials and I don't understand where I went wrong and was directed to this community, hoping someone can help.
On a real display there may be an advantage to using a pot versus a fixed resistor. If the supply voltage can vary then the contrast may need to be adjusted. The correct way to wire a pot is to wire one end of the pot to ground and the wiper to pin 3. The other end of the pot not connected or connected to the wiper. This is contrary to the standing, and incorrect, advice that the pot is wired to ground, Vcc and pin 3.
"ON"
Can't see any meaningful difference there! In any case,
groundFungus:
The correct way to wire a pot is to wire one end of the pot to ground and the wiper to pin 3. The other end of the pot not connected or connected to the wiper. This is contrary to the standing, and incorrect, advice that the pot is wired to ground, Vcc and pin 3.
Well I am pleased!
I can take it a bit easier now, with others on to the matter of this long-standing and somewhat annoying muck-up. And this thread demonstrates that the 1k resistor is close enough to optimum to be a "working straight away" approach rather than needing to get the potentiometer set at least to the correct end of travel before you can even see any display.
groundFungus:
On a real display there may be an advantage to using a pot versus a fixed resistor. If the supply voltage can vary then the contrast may need to be adjusted. The correct way to wire a pot is to wire one end of the pot to ground and the wiper to pin 3. The other end of the pot not connected or connected to the wiper. This is contrary to the standing, and incorrect, advice that the pot is wired to ground, Vcc and pin 3.
Just to be clear about this we are talking about this special case where we desire a variable resistor (also known as a rheostat) and happen to have a potentiometer on hand.
In general the correct way to wire a potentiometer is to use all three terminals. When using only two terminals of a potentiometer you run the risk of exceeding its current carrying capabilities as you reduce the resistance down toward zero ohms. Rheostats are designed to minimize this risk.
In this case there are other resistors to limit the current so the risk is not present.
