1 - I got power to the display
2 - I installed the contract pot and I verified, by checking the middle connection it was varying voltage to pin 3 of the LCD.
3 - However, when I turned contrast with pin 3 connected there was no change to the display. I did not see character line.
4 - I did continue and finished the wiring and verified by matching the colors with the pins with the document.
5 - I made the change to the "Hello World" LCD example (it did not quite match what was in the tutorial, but as a programmer I can adapt. (see code below)
6 - Uploaded the program and, well...nothing.
I added Serial.println to monitor and the program was running and I noticed the serial TX light flash so the Arduino was working.
I went through the build twice and was super careful (so I thought) so I don't know what to test for or how to tell if maybe this is just a defective display.
I stopped typing because I had an idea. I removed everything from the breadboard, then starting from scratch I
1 - Wired power from the Arduino to the breadboard and verified 5V
2 - Took a (+) and (-) wires to the contrast pot
3 - Installed a wire on the middle pin of CP then put a tester (grounded to BB) on that wire
I saw volts move from 0 - 5v
4 - I put the middle pin wire onto pin3 of the display
5 - I put wires from the (+)(-) part of BB directly to pin 15 (+) and 16(-) of the LCD and it lit up.
I moved the CP and there was no change to the Display. I did not see any character pixels, nothing. Is it possible this is defective for one other test I did was check that something was coming from the arduino. It was.
Not sure, other than reaching out directly to Adafruit, but this is frustrating.
Code: Select all
/*
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
modified 7 Nov 2016
by Arturo Guadalupi
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/LiquidCrystalHelloWorld
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
//const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
const int rs = 7, en = 8, d4 = 9, d5 = 10, d6 = 11, d7 = 12;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
Serial.begin(115200);
Serial.println("set up");
// LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
Serial.println("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("Hello time: " + (millis() / 1000));
Serial.println(millis() / 1000);
delay(3000);
}
https://drive.google.com/file/d/1_4WHso ... sp=sharing