jim hamblen / Mbed 2 deprecated LED_RTOS

Demo of LED lighting effects using PWM and wait for time delays. Pins are setup for LPC1768 platform’s LEDs. For complete information, see http://developer.mbed.org/users/4180_1/notebook/led-lighting-effects-for-modelers/

Dependencies:   mbed-rtos mbed

main.cpp@0:9439ccb44422, 2014-11-28 (annotated)

Committer:
4180_1
Date:
Fri Nov 28 18:00:06 2014 +0000
Revision:
0:9439ccb44422
ver 1.0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
4180_1 0:9439ccb44422 1 #include "mbed.h"
4180_1 0:9439ccb44422 2 #include "rtos.h"
4180_1 0:9439ccb44422 3 DigitalOut myled(LED1);
4180_1 0:9439ccb44422 4 PwmOut myled2(LED2);
4180_1 0:9439ccb44422 5 PwmOut myled3(LED3);
4180_1 0:9439ccb44422 6 PwmOut myled4(LED4);
4180_1 0:9439ccb44422 7
4180_1 0:9439ccb44422 8 inline float random_number(){
4180_1 0:9439ccb44422 9 return (rand()/(float(RAND_MAX)));
4180_1 0:9439ccb44422 10 }
4180_1 0:9439ccb44422 11
4180_1 0:9439ccb44422 12 void beacon(void const *args){
4180_1 0:9439ccb44422 13 while(1) {
4180_1 0:9439ccb44422 14 //LED warm up effect using PWM
4180_1 0:9439ccb44422 15 for(int i=0; i<50; i++) {
4180_1 0:9439ccb44422 16 myled2 = i/50.0;
4180_1 0:9439ccb44422 17 Thread::wait(1000.0*0.02);
4180_1 0:9439ccb44422 18 }
4180_1 0:9439ccb44422 19 //LED at full brightness level
4180_1 0:9439ccb44422 20 myled2 = 1.0;
4180_1 0:9439ccb44422 21 Thread::wait(1000.0*0.25);
4180_1 0:9439ccb44422 22 //LED cool down effect using PWM
4180_1 0:9439ccb44422 23 for(int i=49; i>0; i--) {
4180_1 0:9439ccb44422 24 myled2 = i/50.0;
4180_1 0:9439ccb44422 25 Thread::wait(1000.0*0.02);
4180_1 0:9439ccb44422 26 }
4180_1 0:9439ccb44422 27 //LED off
4180_1 0:9439ccb44422 28 myled2 = 0.0;
4180_1 0:9439ccb44422 29 Thread::wait(1000.0*1.5);
4180_1 0:9439ccb44422 30 }
4180_1 0:9439ccb44422 31 }
4180_1 0:9439ccb44422 32 void welding(void const *args) {
4180_1 0:9439ccb44422 33 float x = 0.0;
4180_1 0:9439ccb44422 34 while(1) {
4180_1 0:9439ccb44422 35 //get a new random number for PWM
4180_1 0:9439ccb44422 36 x = random_number();
4180_1 0:9439ccb44422 37 //add some exponential brightness scaling
4180_1 0:9439ccb44422 38 //for more of a fast flash effect
4180_1 0:9439ccb44422 39 myled3 = x*x*x;
4180_1 0:9439ccb44422 40 //fast update rate for welding flashes
4180_1 0:9439ccb44422 41 Thread::wait(1000.0*0.02);
4180_1 0:9439ccb44422 42 //add a random pause between welds
4180_1 0:9439ccb44422 43 if (random_number()>0.9925) {
4180_1 0:9439ccb44422 44 myled3 = 0.0;
4180_1 0:9439ccb44422 45 Thread::wait(1000.0*4.0*random_number());
4180_1 0:9439ccb44422 46 }
4180_1 0:9439ccb44422 47 }
4180_1 0:9439ccb44422 48 }
4180_1 0:9439ccb44422 49
4180_1 0:9439ccb44422 50 void lighthouse(void const *args){
4180_1 0:9439ccb44422 51 float y=0.0;
4180_1 0:9439ccb44422 52 while(1) {
4180_1 0:9439ccb44422 53 for(double x=0.0; x <= 3.14159; x = x + 0.0314159) {
4180_1 0:9439ccb44422 54 y = sin(x); //nice periodic function 0..1..0
4180_1 0:9439ccb44422 55 myled4 = y*y*y;//exponential effect - needs a sharp peak
4180_1 0:9439ccb44422 56 Thread::wait(1000.0*.025);
4180_1 0:9439ccb44422 57 }
4180_1 0:9439ccb44422 58 myled4 = 0.0;
4180_1 0:9439ccb44422 59 //most lighthouses have a 5 second delay - so add another 2.5
4180_1 0:9439ccb44422 60 Thread::wait(1000.0*2.5);
4180_1 0:9439ccb44422 61 }
4180_1 0:9439ccb44422 62 }
4180_1 0:9439ccb44422 63
4180_1 0:9439ccb44422 64 int main() {
4180_1 0:9439ccb44422 65 Thread thread2(beacon);
4180_1 0:9439ccb44422 66 Thread thread3(welding);
4180_1 0:9439ccb44422 67 Thread thread4(lighthouse);
4180_1 0:9439ccb44422 68 //main runs standard LED blink demo
4180_1 0:9439ccb44422 69 while(1) {
4180_1 0:9439ccb44422 70 myled = 1;
4180_1 0:9439ccb44422 71 Thread::wait(1000.0*0.2);
4180_1 0:9439ccb44422 72 myled = 0;
4180_1 0:9439ccb44422 73 Thread::wait(1000.0*0.2);
4180_1 0:9439ccb44422 74 }
4180_1 0:9439ccb44422 75 }