Sending data to the sparkfun Color LCD

Projects Programming
1

Well I didn't think this would be difficult especially since I am not new at this, but I am having problems writing integer,long,double values to the Sparkfun Color LCD shield.

I have tried to typecast the int,long,double values to char and I get the error invalid conversion from 'char' to 'char*'

here is the code:

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include "WProgram.h"
#include "HardwareSerial.h"
// External Component Libs
#include "LCD_driver.h"

void setup()
{
  ioinit(); //Initialize I/O
  LCDInit(); //Initialize the LCD
  LCDContrast(45);
  randomSeed(analogRead(0));
  
}

void loop()
{
  char val1 = char(random(0,9)); 
  
  LCDPutStr(val1,10,10,WHITE,BLACK);
  
}

Maybe I am just tired and I am doing something wrong any help is appreciated.

Thank You

2

Typecasting doesn't change the underlying data. For example, putting an orange into a bowl marked "apples" doesn't make it an apple.

I assume you want to see a number? So you need to convert from a number to a string (assuming the library doesn't support that). For example here is one way:

 char buf [10];
 sprintf (buf, "%i", random (0, 9));
 LCDPutStr(buf,10,10,WHITE,BLACK);
3

Well I didn't think of that it worked like a charm though thank you so much

4

so what if I wanted to convert an analog input would it look like this?

 char buf [100]; // I am assuming I would have to increase the buffer, or was ten used because I was using 0 through 9?
 sprintf (buf, "%i", analogRead(2));
 delay(250);
 LCDPutStr(buf,10,10,WHITE,BLACK);
5

AnalogRead returns 0 to 1023, so you can see you only need 5 bytes to hold that (4 digits plus the terminating "null" at the end of the string). I used 10 simply to allow a bit of slack. The buffer "buf" just holds the converted string.

6

I just read that from a C++ reference so 10 should still work there thank you