Ultrasonic interfacing using LPC2148

[Nilesh Bhavsar]

#include /* LPC21xx definitions */ #include "lcd.h" void LCD_Init(void); unsigned char String1[16]={" iblocks "}; unsigned char String2[16]={" ARM LPC2148 "}; unsigned int ultrasonic_read() { int b; T1TCR = 0x01; T1TC=0; T1PR=0; T1PC=0; IO1SET =(1<<16); // trig pin of ultrasonic sensor Delay1(100); IO1CLR =(1<<16); while((IO1PIN &0x00020000)==0); //echo pin of ultrasonic sensor T1TCR = 0x00; //enable timer while((IO1PIN &0x00020000)==1); T1TCR = 0x01; //stop timer b=T1TC; return b; } int main(void) { unsigned int a; PINSEL0 = 0x00000000; // Enable GPIO on all pins PINSEL1 |= 0x15000000; PINSEL2 = 0x00000000; Delay(20); IO0DIR = (1<<22) | (1<<21) | (1<<20) | (1<<19) | (1<<18) | (1<<17) | (1<<16); // Set P0.16, P0.17, P0.18, P0.19, P0.20, P0.21, P0.22 as Output IO1DIR =(1<<16)|(0<<17); LCD_Init(); // Initialize LCD LCD_Command(0x01); Delay(20); LCD_Command(0x80); LCD_String(&String1[0]); LCD_Command(0xC0); LCD_String(&String2[0]); Delay(200); LCD_Command(0x01); LCD_String("value:"); while(1) { a=ultrasonic_read(); LCD_Command(0xc0); LCDWriteInt(a,3); } }