convert int to char

Forum 2005-2010 (read only) Hardware Interfacing
1

hi ive searched around and found somestuff on this, what im trying to do is create a simple "count" displayer. i have a lcd and i am using this library http://www.arduino.cc/playground/Code/LCD4BitLibrary. the example code works, i get all the fruit to display just like they should. Now i want to incorperate this lcd into my arduino alarm clock and i need to no how to convert a regular integer into a character. i read something about using "itoa()" but dont understand it, could someone explain.

thanks, this is my LCD www.newhavendisplay.com/specs/NHD-0108CZ-FSW-GBW-3V3.pdf

2

i need to no how to convert a regular integer into a character. i read something about using "itoa()"

If you're using the LCD library, why not use the LCD print methods?

3

i do but then i get a error saying that i havent converted an int to a char correctly.... or something along those lines.

4

I do it half a byte at a time:-

void  lcdDisplayInt(long number){  // display hex number on LCD followed by a space
    long j = 0xf0000000;
    int i = 28;
    byte n;
    for( int k = 0; k<8; k++){
    n = ((number & j) >> i) & 0xf;
    if( n>9 ) n = n + 0x37; else n = n | 0x30;   
    lcd.write(n);
    i-=4;
    j = j >> 4;
    }
   lcd.print(" "); 
}
5

or something along those lines

Try a cast..or something along those lines.

6

wow im realy confused Grumpy_Mike, i dont know how to implement that into my code.

7

I used itoa() to display Int-Values over an Ascii call of the nuelectronics display
here is the code to handle this

On your int´s and define you insert these Char buffer

char buf5[10];

and in the loop you convert the int-value (mine is here "LD") over the buffer to Char.

itoa(LD,buf5,10);
lcd.LCD_3310_write_string( 0, 0, "Ladedruck", MENU_NORMAL);
lcd.LCD_3310_write_string_big( 0, 1, buf5, MENU_NORMAL);

On the Arduino playground it is discibed
Printing Numbers

The itoa() stdlib C library function can be used to convert a number into a string, in a variety of bases (e.g. decimal, binary). The buffer must be large enough to hold the largest number, plus sign and terminating null: e.g. 32 bit base-10: "-2147483648\0" = 12 characters.

The stdlib itoa() library routine adds around 600 bytes, the roll-your-own K&R implementation, which includes string.h, adds around 670 bytes. Using snprintf() from stdio.h adds just over 2200 bytes.

e.g.

char buf[12]; // "-2147483648\0"
lcd.printIn(itoa(random(1024)-512, buf, 10));