๐Ÿ“ฃ๐Ÿ“ช ๐Ÿšš Adafruit will not be shipping USPS orders Monday October 14, 2019 ๐Ÿ—“. Expedited USPS orders placed after 11am ET ๐Ÿ•š Friday October 11 will go out Tuesday October 15 ๐Ÿ“ฃ๐Ÿ“ช๐Ÿšš
0

LCD 20, 4 wont work. What am I doing wrong?
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

LCD 20, 4 wont work. What am I doing wrong?

by mradjuster on Mon May 06, 2019 12:29 pm

I have the RGB backlight negative LCD 20x4 + extras - RGB on black with a Uno. I have rewired at least 4 times to no avail. I simply can't get it to work. Here is the code I used. Can anyone help me and tell me what im doing wrong. Attached are photos and code... Thank you for any advise

Code: Select all | TOGGLE FULL SIZE
// 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;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(20, 4);
  // 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);
}
Attachments
thumbnail_IMG_1370.jpg
thumbnail_IMG_1370.jpg (184.25 KiB) Viewed 158 times
thumbnail_IMG_1369.jpg
thumbnail_IMG_1369.jpg (184.48 KiB) Viewed 159 times

mradjuster
 
Posts: 3
Joined: Mon May 06, 2019 9:50 am

Re: LCD 20, 4 wont work. What am I doing wrong?

by adafruit_support_carter on Mon May 06, 2019 2:53 pm

Try turning the trim pot to adjust contrast and see if that helps.

adafruit_support_carter
 
Posts: 13163
Joined: Tue Nov 29, 2016 2:45 pm

Re: LCD 20, 4 wont work. What am I doing wrong?

by mradjuster on Mon May 06, 2019 3:09 pm

I tried. Nothing. The Sketch compiles and uploads but nothing is outputted to the screen. I went by two or three wire schemas but nothing ever printed to the screen. It has to be something simple cause I did everything I could with my basic knowledge...

mradjuster
 
Posts: 3
Joined: Mon May 06, 2019 9:50 am

Re: LCD 20, 4 wont work. What am I doing wrong?

by adafruit_support_carter on Mon May 06, 2019 3:20 pm


adafruit_support_carter
 
Posts: 13163
Joined: Tue Nov 29, 2016 2:45 pm

Re: LCD 20, 4 wont work. What am I doing wrong?

by mradjuster on Mon May 06, 2019 3:27 pm

I tried that one already only to realize I have an 18 pin and the last four are reserved for the back lighting. I even shifted them over two spots on the left for the data pins and I get lighting but nothing is being written to the board. I know I coded the RS correct but is it in the right spot on the uno... I feel like Iโ€™m close but no ah hah moment...

mradjuster
 
Posts: 3
Joined: Mon May 06, 2019 9:50 am

Re: LCD 20, 4 wont work. What am I doing wrong?

by adafruit_support_carter on Mon May 06, 2019 3:49 pm

Correct, the extra pins are for the backlight. Treat them the same as pin #16 in the wiring linked. But for the others, match to what is shown.

adafruit_support_carter
 
Posts: 13163
Joined: Tue Nov 29, 2016 2:45 pm

Please be positive and constructive with your questions and comments.