Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

Modified Hello World

Topic last updated 06 Mar 2012, by Yuji Hosogaya. 1 reply
Kevin Marinelli
14 Feb 2012

I received my LPC1768 controller today so I thought I would fire it up to see if I could make it do something simple. This is a modified version of "Hello World" which cycles through all 4 LEDs, just to see if I could properly address them in sequence.

--

#include "mbed.h"


DigitalOut myled1(LED1);
DigitalOut myled2(LED2);
DigitalOut myled3(LED3);
DigitalOut myled4(LED4);

int main() {
    int i;
    DigitalOut *myled;
    i=0;
    while (1) {
        switch (i) {
            case 0:
                myled=&myled1;
                break;
            case 1:
                myled=&myled2;
                break;
            case 2:
                myled=&myled3;
                break;
            case 3:
                myled=&myled4;
                break;
            default:
                break;
        }
        *myled = 1;
        wait(0.5);
        *myled = 0;
        wait(0.5);
        i++;
        i=i%4;
    }
}

---

Yuji Hosogaya
06 Mar 2012

Probably, it can be shorten like this though I haven't tested.

#include "mbed.h"

DigitalOut leds[]={(LED1),(LED2),(LED3),(LED4)};

int main() {
    int i=0;
    while (1) {
        leds[i] = 1;
        wait(0.5);
        leds[i] = 0;
        wait(0.5);
        i=++i%4;
    }
}