n00bie qustion about converting INT to CHAR

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

Question: how to convert from INT to Character so lcd.printIn works..
Analog read --> returns an INT
lcd.printIn --> wants a CHAR

Error
In function 'void loop()':
error: invalid conversion from 'int' to 'char*' At global scope:

Sample code
//example use of LCD4Bit library
#include <LCD4Bit.h>
//create object to control an LCD.
LCD4Bit lcd = LCD4Bit(4);

int analogpin0 = 0; // slider variable connecetd to analog pin 0
int value1 = 0; // variable to read the value from the analog pin 0
char value2 ;

void setup() {
lcd.init();
}

void loop() {
// new stuff

value1 = analogRead(analogpin0); // reads the value of the variable resistor
delay(100); // this small pause is needed between reading two

lcd.clear();
// new stuff
lcd.printIn(value1);
// lcd.printIn(char analogRead(analogpin0));

}
}

2

after a bunch of searching, the answer seems to be:
"You can use the standard function atoi() to convert an integer to a string. (That function isn't big, unlike sprintf, which uses about 1.5k!) "

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1160586800/0#4

-------------------- here is the working code --------------
//example use of LCD4Bit library
//#include <stdlib.h>
#include <LCD4Bit.h>
//create object to control an LCD.
LCD4Bit lcd = LCD4Bit(4);

int analogpin0 = 0; // slider variable connecetd to analog pin 0
int value1 = 0; // variable to read the value from the analog pin 0
char value2[4] ;

void setup() {
lcd.init();
}

void loop() {
// new stuff

value1 = analogRead(analogpin0); // reads the value 0-1023
delay(100); // this small pause is needed between reading two

lcd.clear();
// new stuff
itoa (value1, value2, 10);
lcd.printIn(value2);
// lcd.printIn(char analogRead(analogpin0));

}

3

You save my day ! A very big thank you! :-*

4

There is an error in that post. Value2 needs to be 5 bytes so it can hold the terminating zero.

It should be:
char value2[5];

5

By the way, your quote above incorrectly says atoi() but the code says itoa(). Important distinction.