Hi all,

I trying to display ac voltage on LCD using micro-controller using PIC18F45K50. I am capturing the voltage and performing A/D Conversion.
Though i could see the variations with different Inputs in ADC register but I am unable to display the same on LCD.

I am using MPlab X IDE 3.2

 

I am using sprintf statement before LCD Statement so that it converts to string.
When i build the program it shows no errors but i am not able to see a single text on LCD when whole circuit is connected to AC mains.

 

Maybe you forgot the code it helps to see it here and on the LCD plz post your code so we can help you.

 

ok...

Here is the code

void ms_delay(unsigned int delay);
void ADC_Init();

unsigned int v;
long temp;
unsigned int delayinms;
char *volt = "00.0";
char s[20];

float t[40];
float  txt[5], txt1[5];

float max_Value,avg,sum=0.0;
int i;

float loc_max,inputarray[500];
int j;
unsigned int result;

void ADC_Init()
{
  ADCON0 = 0b00010101;               //Analog channel 5 and ADC is enabled
  ADCON1 = 0b10000000 ;              // selects the trigger from CTMU
  ADCON2 = 0b10110010;               // Right Justified , 16TAD , Fosc/32
}

void ms_delay(unsigned int delay)
{
    unsigned int delayinms;   
    for(delayinms=0;delayinms<delay;delayinms++)
    {
     __delay_ms(10); 
    } 
}

unsigned int  GetADCValue(unsigned int Channel)
{
    ADCON0bits.ADON =1;                              // ADC Enable
    ms_delay(5) ;                                            // Time for Acquisition capacitor
                                            // to charge up and show correct value
    GO_nDONE  = 1;                    // Enable Go/Done
    while(GO_nDONE);        // Wait for conversion completion
    return ((ADRESH<<8)+ADRESL);   // Return 10 bit ADC value
}

void main()
{
  ANSELA = 0X00;
  ANSELB = 0X00;
  ANSELC = 0X00;
  ANSELD = 0X00;
  ANSELE = 0x03;
  TRISA = 0x00;
  TRISB = 0x04;
  TRISC = 0X00;
  TRISD = 0X00;
  TRISE = 0xFF;
  
  Lcd_Init();
  ADC_Init();
while(1)
{ 
    result=GetADCValue(5);
    max_Value= 0;
    for (i=0;i<4;i++) 
    {
        loc_max= 0;
        do{ 
            result=GetADCValue(5);
          } while(result==loc_max);
        for (j=0; j<249; j++)   
        {
          result=GetADCValue(5); 
          if(result>loc_max) 
          loc_max = result;
        }   
      max_Value = loc_max;
      sum = sum + max_Value;
      avg = sum/5;    //get average of 5 signals
      //v= avg;
      avg= avg*0.707106781;
    
    
      sprintf(s,"voltage:%f",avg);
      Lcd_Write_String(s);
      //Lcd_Set_Cursor(1,1);
      //Lcd_Write_String("Voltage:");
      //Lcd_Set_Cursor(2,1);
     // Lcd_Write_String(v);
    }
  
}
}

 

1. Show that you can blink a LED.
2. Show that you can display AA string.
3. Show that you can display a strig converted from a numeric value.
4. Show that you can display AA string converted from a numeric variable.

Ones step at a time, in that specific order.

 

dannyf thanks for your reply.

Well i tried making led OFF whenever there is zero value on ADC and led to ON whenever it is not equal to zero.

while(1)
{
result=GetADCValue(5);
if(result==0x00)
{

PORTBbits.RB7 = 0;
ms_delay(50);

}
else
{
PORTBbits.RB7 = 1;
}
}

but i am see led is ON irrespective of Changes in AC input Voltage.

And dannyf can you pls tell me what is AA string?!! Because i am newbie in micro-controller coding!!
But i could understand what you are trying to say.

Pls don't mind if am asking very stupid question.