PIC16F877 and ADC example

In the following example project we will convert an analog input to channel 0 to 10 bit digital number and display it on an LCD

 

Schematic

Code

[c]
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;

unsigned int adcvalue,value,temp_res;

unsigned char car,x,y;
// Routine to show the value of the ADC_read

void ShowADC(int x, int y, unsigned int adcvalue)

{

car = adcvalue / 1000;

LCD_Chr(x,y,48+car);

adcvalue=adcvalue-1000*car;

car = (adcvalue / 100);

LCD_Chr_CP(48+car);

adcvalue=adcvalue-100*car;

car = (adcvalue / 10);

LCD_Chr_CP(48+car);

adcvalue=adcvalue-10*car;

car = adcvalue;

LCD_Chr_CP(48+car);

delay_ms(30);

}
void main()

{

TRISA = 0xFF; // PORTA is input

TRISB = 0;

PORTB = 0;

Lcd_Init(); // Initialize LCD

Lcd_Cmd(_LCD_CLEAR); // Clear display

Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor off

do {

temp_res = ADC_Read(0); // Get 10-bit results of AD conversion

adcvalue = temp_res;

ShowADC (1,1,adcvalue);

Delay_ms(300);
} while(1);
} // end main
[/c]
 
Links

Microcontroller Programmer Kit Development Board for PIC microcontroller evaluation QL200 PIC