ARM LPC2138/48 Mini Development Board – LED Interfacing

LPC 2138/48 mini development board has 3 SMD LED s connected to port pins P0.17, P0.18 & P0.19 via jumpers J1 , J2 & J3. If any jumper is left open, then the corresponding port pin can be used independently. The sample code given below toggles the LEDs in fixed intervals.

SchematicNote: To use the LEDs, don’t forget to short the corresponding jumpers J1, J2 & J3. Leaving them open frees P0.17, P0.18 & P0.19 and can be used for any other desired purpose.

Sample Code

/*************************************************************************
                                HEADER FILE
**************************************************************************/
#include<lpc21xx.h>

/*************************************************************************
* Function    : Delay                                                    *
*                                                                        *
* Description : Function for delay                                       *
*                                                                        *
* Parameter   : val - the value for delay                                *
**************************************************************************/
void Delay(unsigned long val)
{
 while(val>0)
 {
  val--;
 }
}

/*************************************************************************
                               MAIN FUNCTION
**************************************************************************/
int main()
{
 IO0DIR  = 0XFFFFFFFF;      /* Set Port0 as output                       */
 while(1)                   /* Infinite loop                             */
 {
  IO0SET = 0X000E0000;      /* Set P0.17,P0.18,P0.19 at logic high state */
  Delay(1000000);           /* Delay of 100ms                            */
  IO0CLR = 0X000E0000;      /* Set P0.17,P0.18,P0.19 at logic low state  */
  Delay(1000000);
 }
}

/***************************  END OF PROGRAM  ****************************/