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Topic: Strange LCD 16x2 (Read 192 times) previous topic - next topic

18avf

Jul 22, 2018, 01:06 pm Last Edit: Jul 22, 2018, 01:11 pm by 18avf
Does anyone have met this type of lcd? It has 17 colons and 2 raws and a single block of 17x17
https://ibb.co/gej7KJ

Paul__B


No, but it will presumably code as a 20 by 2.  You have eight user-defined characters available and six character spaces to fill, so it should be entirely possible to generate any (single or able to be slightly animated) icon to fit in that space.

Sounds like fun!

floresta

#2
Jul 22, 2018, 04:12 pm Last Edit: Jul 22, 2018, 04:14 pm by floresta
It looks like he is running the "Hello World program from the LiquidCrystal tutorial, probably using the LiquidCrystal library.  

The library is obviously functioning but since the characters are in the wrong place this device may have a non-standard memory scheme.  (He may also have messed up his cursor positioning for the second row.)

The next step would be to send the device 80 sequential 'printable' ASCII characters and find out where they appear on the display.  This program should work, make sure you let it run for a while:

Code: [Select]
#include <LiquidCrystal.h>

//LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
  LiquidCrystal lcd(12, 11,  5,  4,  3,  2);   // put your pin numbers here

void setup()
  {
    lcd.begin(20, 4);                          // put whatever you used before here !
    for (char i=47; i<127; i++)                // send 80 consecutive displayable characters to the LCD
      {
        lcd.print(i);
        delay(100);                            // this delay allows you to observe the addressing sequence
      }
  }


void loop()
  {  
  }


Don

18avf

When it goes beyond the last column, it overwrites some dots...

floresta

#4
Jul 23, 2018, 12:09 am Last Edit: Jul 23, 2018, 12:11 am by floresta
When it goes beyond the last column, it overwrites some dots...
I'm not sure what you are trying to say.  Can you post a picture of the result after the program runs?

What are you using for the parameters of the lcd.begin(...) statement?

Don

photoncatcher

To me it looks like a defect 2x20 LCD display. All 'character' LCD displays I have ever seen have 8x5 pixel character blocks. In this display there are columns of single pixels between character blocks 18,19 and 20! Very, very unusual.   

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