1. GPIO Seven Segment Display Interface
Program Statement: Interface four seven segment displays on GPIO’s of ARM7 LPC2148 and write a
C code to display count 0000 to 9999 on them with appropriate delay.
Solution:
# include<lpc214x.h>
void delay(void);
main()
{
char num[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x67};
char t,j,h,i,k;
int m;
char num1[] = {0x00,0x00,0x00,0x00};
char num2[] = {0x70,0xb0,0xd0,0xe0};
int y;
IO0DIR = 0x00ffff00;
for(y=1;y<10000;y++)
{
if(y<10)
{
num1[3]=num[0];
num1[2]=num[0];
num1[1]=num[0];
num1[0]=num[y];
}
else if (y>= 10 && y <100)
{
num1[3]=num[0];
num1[2]=num[0];
num1[1]=num[y/10];
num1[0]=num[y-((y/10)*10)];
}
else if (y>= 100 && y <1000)
{
num1[3]=num[0];
num1[2]=num[y/100];
num1[1]=num[(y-((y/100)*100))/10];
num1[0]=num[y-((y/100)*100)-(((y-((y/100)*100))/10)*10)];
}
else
{
num1[3]=num[y/1000];
num1[2]=num[(y-((y/1000)*1000))/100];
LPC2148 Lecture Notes ENT505 Prof. Anish Goel Page 1

2. num1[1]=num[(y-((y/1000)*1000)-((y/100)*100))/10];
num1[0]=num[y-((y/1000)*1000)-((y/100)*100)-((y/10)*10)];
}
for(m=0;m<2;m++)
{
for(t=0;t<4;t++)
{
IO0SET = (num1[t] << 16) | (num2[t] << 8);
delay();
IO0CLR = (num1[t] << 16) | (num2[t] << 8);
delay();
}
}
}
}
void delay(void)
{
long int t;
for(t=0;t<30000;t++);
}
Serial Interface UART Block
Problem Statement: Write a program to send a string on serial port UART0 of LPC2148 continuously
at 9600 baud.
Solution Clue:
#include"LPC214x.h"
void Initialize(void);
/* Macro Definitions */
#define TEMT (1<<6);
#define LINE_FEED 0xA;
#define CARRIAGE_RET 0xD;
/************************* MAIN *************************/
int main()
{
int i;
char c[]="Philips LPC";
Initialize();
/* Print forever */
while(1)
{
i=0;
LPC2148 Lecture Notes ENT505 Prof. Anish Goel Page 2

3. /* Keep Transmitting until Null character('0') is reached */
while(c[i])
{
U0THR=c[i];
i++;
}
U0THR=LINE_FEED;
U0THR = CARRIAGE_RET;
/* Wait till U0THR and U0TSR are both empty */
while(!(U0LSR & (1<<6)))
{}
}
}
/*************** System Initialization ***************/
void Initialize()
{
/* Initialize Pin Select Block for Tx and Rx */
PINSEL0=0x5;
/* Enable FIFO's and reset them */
U0FCR=0x7;
/* Set DLAB and word length set to 8bits */
U0LCR=0x83;
/* Baud rate set to 9600 */
U0DLL=0x10;
U0DLM=0x0;
/* Clear DLAB */
U0LCR=0x3;
}
/*********************************************************/
16x2 LCD Program Hint
#include<lpc214x.h>
#include<STDIO.H>
#define line0 0x80
#define line1 0xc0
void delay(void);
void delay1(void);
void comdisp(char);
void comdata(char);
void display(char*,char);
main()
{
unsigned int x;
LPC2148 Lecture Notes ENT505 Prof. Anish Goel Page 3

4. IO0DIR=0xffffffff;
comdisp(0x38);
comdisp(0xf);
comdisp(0x6);
comdisp(0x87);
comdisp(0x1);
display("LPC 2148",line0);
display("ARM 7",line1+3);
}
void display(char *dat,char addr)
{
char count;
comdisp(addr);
for(count=0;dat[count];count++)
{
comdata(dat[count]);
}
}
void comdisp(char lcddata)
{
char word = 0xf9;
char word1 = 0xf1;
IO0SET = (lcddata<<8) | word;
delay1();
IO0SET = IO0SET && word1;
delay();
IO0CLR = 0x0000;
}
void comdata(char lcddata)
{
char word = 0xf3;
char word1 = 0xfb;
IO0SET = (lcddata<<8) | word;
delay1();
IO0CLR = ~(IO0SET && word1);
delay();
IO0CLR = 0xffff;
}
void delay(void)
{
int t;
for(t=0;t<1;t++);
}
void delay1(void)
{
int t;
for(t=0;t<1;t++);
}
LPC2148 Lecture Notes ENT505 Prof. Anish Goel Page 4