[SOLVED] Need Conditional output for lcd voltmeter

[khaled01819]

Hi All, I am very new here
I have collect the following c-code for 20V LCD Voltmeter using pic16F688, now i want to activate RA0 pin high when LCD voltage is grater than or equal 10.0v, what is the change need in this code? Please help....

char Message1[] = "DVM Project";
unsigned int ADC_Value, DisplayVolt;
char *volt = "00.0";

void main() {

ANSEL = 0b00000100; // RA2/AN2 is analog input
ADCON0 = 0b00001000; // Analog channel select @ AN2
ADCON1 = 0x00; // Reference voltage is Vdd
CMCON0 = 0x07 ; // Disable comparators
TRISC = 0b00000000; // PORTC All Outputs
TRISA = 0b00001100; // PORTA All Outputs, Except RA3 and RA2
Lcd_Init(); // Initialize LCD
Lcd_Cmd(_LCD_CLEAR); // CLEAR display
Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor off
Lcd_Out(1,1,Message1);
Lcd_Chr(2,10,'V');

do {

ADC_Value = ADC_Read(2);
DisplayVolt = ADC_Value * 2;
volt[0] = DisplayVolt/1000 + 48;
volt[1] = (DisplayVolt/100)%10 + 48;
volt[3] = (DisplayVolt/10)%10 + 48;
Lcd_Out(2,5,volt);
delay_ms(500); // Hold for 500 ms

} while(1);
} // End main()

 

[aProgrammer]

after

volt[0] = DisplayVolt/1000 + 48;

add :

RA0 = (volt[0] >= '1') ? 1 : 0;

 

[khaled01819]

Success! A lot of thanks for help.

 

[jayanth.devarayanadurga]

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Code C - [expand]
1
2
if(DisplayVolt >= 10)PORTA.F0 = 1;
else PORTA.F0 = 0;

---

 

[aProgrammer]

Then try :

PORTA0 = (volt[0] >= '1') ? 1 : 0;
or
PORTA.0 = (volt[0] >= '1') ? 1 : 0;
...

or perhaps

if (volt[0] >= '1')
PORTA |= 1;
else PORTA &= 0;

 

[khaled01819]

Yes:grin: Success! Thanks for best suggestion. Thanks.............

 

[khaled01819]

But RA0 Pin is all time high even input voltage<= or >= 10.0 volt, plz solve......................

 

[aProgrammer]

please show your code.

 

[jayanth.devarayanadurga]

This is wrong. DisplayVolt = ADC_Value * 2;

Calculate according to your Vref+ and scaled voltage.