Stage-1 Students SoCEM / Mbed OS Task524Solution-FZ429

Updated for the FZ429

main.cpp@2:a49804b6dbec, 2018-11-12 (annotated)

Committer:
noutram
Date:
Mon Nov 12 14:36:33 2018 +0000
Revision:
2:a49804b6dbec
Parent:
0:f3eff68b603f 
Updated for the FZ429

Who changed what in which revision?

UserRevisionLine numberNew contents of line
noutram 0:f3eff68b603f 1 #include "mbed.h"
noutram 0:f3eff68b603f 2
noutram 0:f3eff68b603f 3 //Global PWM object
noutram 2:a49804b6dbec 4 PwmOut pwmRed(D6);
noutram 0:f3eff68b603f 5
noutram 0:f3eff68b603f 6 int T = 100; //100uS
noutram 0:f3eff68b603f 7 volatile int Tmark = 0; //0us
noutram 0:f3eff68b603f 8 volatile int delta = 1; //1us
noutram 0:f3eff68b603f 9 int n=0;
noutram 0:f3eff68b603f 10
noutram 0:f3eff68b603f 11 //Timer
noutram 0:f3eff68b603f 12 Ticker t;
noutram 0:f3eff68b603f 13
noutram 0:f3eff68b603f 14 //Function prototype
noutram 0:f3eff68b603f 15 void doTwinkle();
noutram 0:f3eff68b603f 16
noutram 0:f3eff68b603f 17 int main() {
noutram 0:f3eff68b603f 18
noutram 0:f3eff68b603f 19 //Initial PWM state
noutram 0:f3eff68b603f 20 pwmRed.period_us(T);
noutram 0:f3eff68b603f 21 pwmRed.pulsewidth_us(Tmark);
noutram 0:f3eff68b603f 22
noutram 0:f3eff68b603f 23 //Start timer
noutram 0:f3eff68b603f 24 t.attach(doTwinkle, 0.01);
noutram 0:f3eff68b603f 25
noutram 0:f3eff68b603f 26 while(1) {
noutram 0:f3eff68b603f 27 sleep();
noutram 0:f3eff68b603f 28
noutram 0:f3eff68b603f 29 //Update PWM
noutram 0:f3eff68b603f 30 pwmRed.pulsewidth_us(Tmark);
noutram 0:f3eff68b603f 31
noutram 0:f3eff68b603f 32 //printf("Tmark = %d\n", Tmark); //Debug
noutram 0:f3eff68b603f 33 }
noutram 0:f3eff68b603f 34 }
noutram 0:f3eff68b603f 35
noutram 0:f3eff68b603f 36 //ISR for Timer
noutram 0:f3eff68b603f 37 void doTwinkle()
noutram 0:f3eff68b603f 38 {
noutram 0:f3eff68b603f 39 //Update n
noutram 0:f3eff68b603f 40 n++;
noutram 0:f3eff68b603f 41
noutram 0:f3eff68b603f 42 //Calculate t
noutram 0:f3eff68b603f 43 float t = (float)n / (float)T;
noutram 0:f3eff68b603f 44 float y = sin(2.0f*3.1415926f*t); //Range -1...+1
noutram 0:f3eff68b603f 45 Tmark = (int)(0.5f*(y+1.0f)*T); //Range 0..T
noutram 0:f3eff68b603f 46 }