lcd output works sometimes and others showes odd things

[sean2k5]

well my code to get pretend voltage from a 10k pot works great sometimes but others it will show random things even sometimes on the wrong line

im using mikroC and a pic 18f4550

what i thing is wrong is FloatToStr because if i remove that part of the code everything is great


please help me and thank you

sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;

sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections

int raw ;
float convert;
float volts ;
char strDisplay;



void main(){


OSCCON = 0x72; // OSCOLATOR
ADCON1 = 0x0E; // all pins digital but AN0
CMCON |=0x07; // Disable comparators


TRISA.F0 = 1; // Switch Location set to in

Lcd_Init(); // Initialize LCD
Lcd_Cmd(_LCD_CURSOR_OFF);
Lcd_Cmd(_LCD_CLEAR);

while (1){



raw = ADC_Read(0);
convert = raw * 0.0048875855327468;
volts = convert * 4.0;

FloatToStr(volts, strDisplay);

Lcd_Out(1, 1, "Pretend Volts is");
Lcd_Out(2, 2, strDisplay);
Delay_ms(1000);
Lcd_Cmd(_LCD_CLEAR);
}
}

 

[FvM]

The shown code can't work. strDisplay must be of type *char, e.g. strDisplay[15] or larger.

 

[sean2k5]

thank you that fixed it !!!
well im learning this with out any help but the internet so can you point me to a website or explain it to me why i had to add the [15] to the end of char?

 

[kripacharya]

char strDisplay will allocate only 1 byte for storage, but you need more storage than this for your string conversion. char strDisplay[xx] will allocate xx bytes of storage, and then passing variable strDisplay to LCD_Out it will be a pointer, which is what is required.