main.cpp

00001 #include "mbed.h"
00002 #include "rtos.h"
00003 PwmOut rled(D3);
00004 PwmOut gled(D5);
00005 PwmOut bled(D6);
00006 DigitalOut led_common(D4);
00007 
00008 typedef struct {
00009     float red;
00010     float green;
00011     float blue;
00012 } message_t;
00013 
00014 Mail <message_t,4> mbox;                            //Mailbox for 4 messages
00015 
00016 void led_thread(void const *argument) {
00017     rled.period_ms(20);                             //Set period to 20 ms
00018     rled.write(1.0f);                               //Initialize to 0% duty cycle
00019     gled.period_ms(20);                             //Set period to 20 ms
00020     gled.write(1.0f);                               //Initialize to 0% duty cycle
00021     bled.period_ms(20);                             //Set period to 20 ms
00022     bled.write(1.0f);                               //Initialize to 0% duty cycle
00023     while (true) {
00024         osEvent evt = mbox.get();                   //Wait for a message
00025         if(evt.status == osEventMail) {
00026             message_t *mymessage = (message_t*)evt.value.p;
00027             rled = 1.0f - mymessage->red;
00028             gled = 1.0f - mymessage->green;
00029             bled = 1.0f - mymessage->blue;
00030             mbox.free(mymessage);                   //Free up memory
00031         }
00032     }
00033 }
00034 
00035 float frand(void) {
00036     int32_t rv = 0x8000 -(rand()&0xFFFF);
00037     return (rv*rv/1073741824.0f);
00038 }
00039 
00040 int main (void) {
00041     float RGB1[3];
00042     float RGB2[3];
00043     float INC[3];
00044     led_common = 1;         // for commono anode...
00045     Thread thread2(led_thread);
00046 //--- Create a random color ---------------------
00047     for (int x=0; x<3; x++) {
00048         RGB1[x] = frand();
00049     }
00050 
00051     while (true) {
00052 //--- Create a new random color -----------------
00053         for (int x=0; x<3; x++) {
00054             RGB2[x] = frand();
00055         }
00056 //--- Determine increments to go from color 1 to color 2 in 25 steps
00057         for (int x=0; x<3; x++) {
00058             INC[x] = (RGB1[x] - RGB2[x]) / 25;
00059         }       
00060 //--- Send color codes to thread2 ---------------
00061         for (int s=0; s<25; s++) {
00062             message_t *message = mbox.alloc();      //Allocate memory
00063             message->red = RGB1[0];
00064             message->green = RGB1[1];
00065             message->blue = RGB1[2];
00066             mbox.put(message);                      //Send data as message
00067             Thread::wait(100);
00068             for (int x=0; x<3; x++) {
00069                 RGB1[x] -= INC[x];                  //Approach to second colour
00070             }
00071         }
00072     }
00073 }