LCD 4bit help

Forum 2005-2010 (read only) Software Syntax & Programs
1

First off, my code, which works, but I really don't like it.

#include <LCD4Bit_mod.h>
LCD4Bit_mod lcd = LCD4Bit_mod(2);


char* ascii_chart[96] = {  // as the lcd lib wants to print in decimal i'm using this to look up the character
" ", "!", "x", "#", "$", "%", "&", "x", "(", ")", "*", "+", ",", "-", ".", "/",
"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", ":", ";", "<", "=", ">", "?",
"@", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O",
"P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "[", "x", "x", "x", "x",
"`", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o",
"p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "{", "|", "}", "~"
};
int incomingByte = 0;
int charconv = 0;       // incomingByte less 32 as my array starts at [space]
int position = 0;       // horizontal position of cursor
int line = 1;           // vertical positioin of cursor


void setup(){
  lcd.init();
  delay(100);
  lcd.clear();
  Serial.begin(9600);
  }


void loop() { 
      // back to the top left position
  if (line == 2 && position == 16){
      line = 1;
      position = 0;
      lcd.clear();}
      
      // next line                 
  if(line == 1 && position == 16){
     line = 2;
     position = 0;}
                       
  lcd.cursorTo(line, position);
  
      // send data only when you receive data:
      if (Serial.available() > 0) {
            // read the incoming byte:
            incomingByte = Serial.read();
                charconv = incomingByte - 32;
            // say what you got:
            lcd.printIn(ascii_chart[charconv]);
                position ++;
               }
}

The random x's in the array are due to various characters that evidently don't like being between "".

And now my little problem, if I get lcd.printIn to print incomingByte it prints the ascii code as decimal (after going through itoa()), if I make incomingByte a byte variable it errors with invalid conversion from 'byte' to 'char*. I'm thinking there must be a similar function to itoa() that will do what I need.

Any ideas? I'm sure it has to be extremely simple, but like my previous question no amount of reading sparks an answer. :-[

2

First, if you want a char and not a char*, use '' vs. "" (single-quotes vs. double-quotes - you'll save some memory too =)

Secondly, can't you just:

lcd.print(incomingByte);

Just fine? Seems like you're going through a lot of work to print a character read from serial, when you should be able to just print that character w/o issue. Try using lcd.print() which will work with a char vs. lcd.printIn() which requires a char*.

!c

3

Secondly, can't you just:

lcd.print(incomingByte);

lol, yep, knew it would be simple, I've no idea how I missed that

Thanks, and I'll have a go with the single quotes :slight_smile: