Exp. 7.: On-chip ADC Programming in LPC2148 Development Board.

 

CODE

#include <lpc214x.h>

void delay(unsigned char time) {

    unsigned int i, j;

    for (j = 0; j < time; j++) {

        for (i = 0; i < 8000; i++);

    }

}

void LCD_command(unsigned char command) {

    IOCLR0 = 0xFF << 16; // Clear LCD Data lines

    IOCLR1 = 1 << 16; // RS=0 for command

    IOCLR1 = 1 << 17; // RW=0 for write

    IOSET0 = command << 16; // put command on data line

    IOSET1 = (1 << 18); // en=1

    delay(10); // delay

    IOCLR1 = (1 << 18); // en=0

}

void LCDdata(unsigned char data) {

    IOCLR0 = 0xFF << 16; // Clear LCD Data lines

    IOSET1 = 1 << 16; // RS=1 for data

    IOCLR1 = 1 << 17; // RW=0 for write

    IOSET0 = data << 16; // put command on data line

    IOSET1 = (1 << 18); // en=1

    delay(10); // delay

    IOCLR1 = (1 << 18); // en=0

}

void LCDinit() {

    LCD_command(0x38); // 8bit mode and 5x8 dots (function set)

    delay(10); // delay

    LCD_command(0x80); // set cursor to 0th location on 1st line

    delay(10); // delay

    LCD_command(0x01); // clear lcd (clear command)

    delay(10); // delay

    LCD_command(0x06); // cursor increment and display shift (entry mode set)

    delay(10); // delay

    LCD_command(0x0c); // display on, cursor off, cursor character blinking off

}

void LCD_write_string(unsigned char *string) {

    while (*string) { // Check for End of String

        LCDdata(*string++); // sending data on LCD byte by byte

    }

}

int main(void) {

    unsigned int ADCResult = 0;

    unsigned char i, Thousands, Hundreds, Tens, Ones;

    PINSEL1 = 0x04000000;

    PINSEL2 = 0X00; // Configure PORT1 as GPIO

    IODIR1 = 0x07 << 16; // Configure P1.18, P1.17, P1.16 as output

    IODIR0 = 0xFF << 16; // Configure P0.23 - P0.16 as output

    LCDinit(); // Initialize LCD 16x2

    LCD_command(0xc0); // second line

    LCD_write_string("ADC O/P=");

    AD0CR = 0x01200404;

    while (1) {

        AD0CR |= 1 << 24; // Start ADC

        while ((AD0DR2 & 0x80000000) == 0); // Wait for the conversion to be completed

        ADCResult = AD0DR2; // Store converted data

        ADCResult = (ADCResult >> 6) & 0x3FF;

        LCD_command(0xCA); // Goto 10th place on second line of LCD

        i = ADCResult / 1000; // Get the thousands place

        Thousands = i + 0x30; // Convert it to ASCII

        LCDdata(Thousands); // Display thousands place

        i = (ADCResult % 1000) / 100; // Get the Hundreds place

        Hundreds = i + 0x30; // Convert it to ASCII

        LCDdata(Hundreds); // Display Hundreds place

        i = ((ADCResult % 1000) % 100) / 10; // Get the Tens place

        Tens = i + 0x30; // Convert it to ASCII

        LCDdata(Tens); // Display Tens place

        i = ADCResult % 10; // Get the Ones place

        Ones = i + 0x30; // Convert it to ASCII

        LCDdata(Ones); // Display Ones place

        delay(250); // Delay between two conversions

    }

    return 0;

}