File content as of revision 0:d46c7e391377:

#include "mbed.h"
#include "TSISensor.h"

//DigitalOut myled(LED_BLUE);
Serial pc(USBTX, USBRX);
//PwmOut led(LED_GREEN);
//TSISensor tsi;
PwmOut r (LED_RED);
PwmOut g (LED_GREEN);
PwmOut b (LED_BLUE);
Ticker tick;
Timer t;

#define  n    1000//1125
#define  len  10*n/3
void colorswing(void);
int main() 
{
    int   i, j, k, q, x, nines, predigit,digits,total;
    int  a[len];
    
    r.period(0.0001);
    g.period(0.0001);
    b.period(0.0001);
    
    tick.attach(&colorswing, 0.01);
    
    pc.baud(115200);
    pc.printf("\nStart Pi Generator!\n");
    total=0;
    while(1)
    {
        //myled = !myled;
        t.start();
        digits=0;
        for (j=1;j<=len;j++)
            a[j] = 2;      
        nines = 0;
        predigit = 0;//               {First predigit is a 0}
        for (j=1;j<=n;j++)
        {
            q = 0;
            for(i=len;i>0;i--)
            {
                x    = 10*a[i] + q*i;
                a[i] = x % (2*i - 1);
                q    = x / (2*i - 1);
                
            }
            a[1] = q % 10;
            q = q / 10;
            if (q == 9)
            {    nines++;}
            else
            {    if (q == 10)
                {
                    pc.printf("%d",predigit+1);
                    for (k=1;k<=nines;k++)// to nines do
                        pc.printf("0");//            {zeros}
                    predigit = 0;
                    nines = 0;
                }
                else
                {
                    pc.printf("%d",predigit);
                    predigit = q;
                    if (nines != 0)// then
                    {
                        for(k=1;k<=nines;k++)// do
                            pc.printf("9");
                        nines = 0;
                    }
                }
                digits++;digits+=nines;
                
            }
        }t.stop();
        pc.printf("%d\r\nDigits=%d\r\nTotal=%d\r\nTimerRequired=%fsec\r\n",predigit,digits,++total,t.read());
        //led = 1.0 - tsi.readPercentage();
        t.reset();
    }
}

void colorswing()
{
    static float p=0;
    p += 0.003;
    if(p>3)p=0;
    r = 1.0 - ((p < 1.0) ? 1.0 - p : (p > 2.0) ? p - 2.0 : 0.0);
    g = 1.0 - ((p < 1.0) ? p : (p > 2.0) ? 0.0 : 2.0 - p);
    b = 1.0 - ((p < 1.0) ? 0.0 : (p > 2.0) ? 3.0 - p : p - 1.0);        
}