Interrupts On Explore M3

In this tutorial we will discuss how to use the external interrupts on Explore M3.

Prerequisites

Please check this tutorial for detailed explanation on inbuilt Lpc1768 External Interrupts.
If you are doing it for the first time, then check the below links to setup the project for generating the .bin file.

1. Keil4 Setup
2. Keil5 Setup
3. ARM GCC Setup
4. Eclipse & ARM GCC Setup

EINTx Pins

LPC1768 has four external interrupts EINT0-EINT3.
Below table shows mapping of EINTx pins.

Interrupt	LPC1768 Pin	Explore M3 pin	Enum to be used
EINT0	P2.10	ISP	EINT0
EINT1	P2.11	USB_BOOT	EINT1
EINT2	P2_12	30	EINT2
EINT3	P2.13	31	EINT3

Note:

1. ISP Pin is used for ISP programming and it should not be zero during RESET, else the controller will in ISP mode.
2. USB_BOOT Switch is used for Usb/Dfu bootloader and it should not be zero during RESET, else the controller will in USB/DFU boot mode.

Hardware Connection

LED is Connected to pin 13 on Explore M3 board.

Code

Below is the sample code to blink the LED's with 1ms delay using systick timer.

	#include "stdutils.h"
	#include "gpio.h"
	#include "extintr.h"
	#define LED1 13
	#define LED2 14
	void myExtIntrIsr_0(void)
	{
	GPIO_PinToggle(LED1); /* Toggle the LED1 (13) */
	}
	void myExtIntrIsr_1(void)
	{
	GPIO_PinToggle(LED2); /* Toggle the LED2 (14) */
	}
	int main (void)
	{
	SystemInit();
	GPIO_PinDirection(LED1,OUTPUT); /* Configure the pins as Output to blink the Leds*/
	GPIO_PinDirection(LED2,OUTPUT);
	EINT_AttachInterrupt(EINT2,myExtIntrIsr_0,FALLING); /* myExtIntrIsr_0 will be called by EINT2_IRQHandler */
	EINT_AttachInterrupt(EINT3,myExtIntrIsr_1,FALLING); /* myExtIntrIsr_1 will be called by EINT3_IRQHandler */
	while(1)
	{
	//do nothing
	}
	}

view raw exploreM3_extIntr0.c hosted with ❤ by GitHub