I am new to Arduino.
I have connected Topway LCD to my arduino(actually an Eleven) and Nothing displays except black boxes on top line. Fiddleing with contrast makes the black boxes go away and results in a blank screen.
If I connect a lcd from Jaycar( SD1602G2) it works. The Jaycar Pinout is different to normal(15-16 then 1 to 14. Pin 14 is at the corner end), but it still works fine.
Does this mean that the topway LCD is a Dud or is it not compatible with the Library(Liquid Crystal Library ,Standard issue from Arduino ?
I have included Pics of Topway, Jaycar and Code I have uploaded.
Any help appreciated
Does this mean that the topway LCD is a Dud or is it not compatible with the Library(Liquid Crystal Library ,Standard issue from Arduino ?
There's no reason that it should not be compatible with the library and, since you can display the row of boxes, it is not likely to be a dud.
Your photograph is not quite in focus so I can't really check out the soldering job on that display, but that is a possibility. I assume the wire connecting pin 5 to GND is there as well since it shows up in the other picture.
/*
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(9, 8, 7, 6, 5, 4);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
delay(500);
// Print a message to the LCD.
lcd.setCursor(0, 0);
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);
}
Must be a connection problem. I would double-check your soldering of the pins, and that they are properly inserted, and that you have properly grounded RS.
Showing the black characters in this case indicates a reasonably correct setting of the contrast. You do not want them to go away!
Interesting that the Topway datasheet illustrates the correct wiring of the contrast preset. It also specifies that a series resistor is not required for the backlight as this is included and the voltage specified as 5 V.
Have checked the soldering. All looks good. I have now soldered pins on underside of LCD board as well (to be sure to be sure). The problem still persists. I am convinced this LCD has something wrong with it.
I did note that the LCD does not need a current limiting resistor. I felt this restriction might push more current to Pin 2 , just in case it needed a bit more. I have powered from USB and also using a 9V 350ma plug pack.
