Hi to all, I am new to ARM world. Now i am trying with lpc2148. I have to write program for 4x4 keypad. So i thought to start with a single push button. i have written code for 16x2 LCD display. Now i am trying to type any char on keypad and display it on LCD. My LCD is working fine. I have written a code for single key. i ran that program and got no error. But when i debugging it the control does not enter in the coding. its stopped on SWI_Handler B SWI_Handler line. Using my code i am trying to read Here's my code
#include<lpc214x.h> #include<stdio.h> void delay(void); //void keydetection(void); unsigned int i,j,k; int main() { IODIR0=0x00000000;//make all pins as input PINSEL0=0x00000000;//make all pins as GPIO's k=0x00000000;//make k as 32 bit variable while(1) { IOSET0=0x00000001;//setting P0.0 pin as high k=IOPIN0;//reading the states of P0.0 pin nd storn to k printf("%d",k); if(IOPIN0 && 0x00000001)//checkin P0.0 as high or not IOSET0=0x00000011;//if its correct then P0.1 as high delay(); IOCLR0=0x00000001; k=IOPIN0; printf("%d",k); if(IOPIN0 && 0x00000000) IOSET0=0x00000000; delay(); } } void delay(void) { for(i=0;i<40000;i++) { ; } }
Not only for this coding i am asking this doubt. My friends used to get this problem somany time. What this error exactly trying to say? What should i commenly do if i get this error? and whats the commen way to avoid this error?