University of Plymouth - Stages 1, 2 and 3 / Mbed OS Task525Solution

Task 5.2.5 Solution

main.cpp@2:7f90edec13b7, 2019-09-20 (annotated)

Committer:
noutram
Date:
Fri Sep 20 13:46:41 2019 +0000
Revision:
2:7f90edec13b7
Parent:
0:3506f73fe611 
2019

Who changed what in which revision?

UserRevisionLine numberNew contents of line
noutram 0:3506f73fe611 1 #include "mbed.h"
noutram 0:3506f73fe611 2
noutram 0:3506f73fe611 3 //Global PWM object
noutram 2:7f90edec13b7 4 #ifdef TARGET_NUCLEO_F429ZI
noutram 2:7f90edec13b7 5 PwmOut pwmRed(D6); //D7 is not a PWM output on the F429, so use D6 instead
noutram 2:7f90edec13b7 6 #else
noutram 0:3506f73fe611 7 PwmOut pwmRed(D7);
noutram 2:7f90edec13b7 8 #endif
noutram 0:3506f73fe611 9
noutram 0:3506f73fe611 10 InterruptIn SWOn(D4); //Fade ON
noutram 0:3506f73fe611 11 InterruptIn SWOff(D3); //Fade OFF
noutram 0:3506f73fe611 12
noutram 0:3506f73fe611 13 int T = 100; //100uS
noutram 0:3506f73fe611 14 volatile int Tmark = 0; //0us
noutram 0:3506f73fe611 15 volatile int delta = 1; //1us
noutram 0:3506f73fe611 16
noutram 0:3506f73fe611 17 //Timer
noutram 0:3506f73fe611 18 Ticker t;
noutram 0:3506f73fe611 19
noutram 0:3506f73fe611 20 //Function prototype
noutram 0:3506f73fe611 21 void doTwinkle();
noutram 0:3506f73fe611 22 void doSwitchON();
noutram 0:3506f73fe611 23 void doSwitchOFF();
noutram 0:3506f73fe611 24
noutram 0:3506f73fe611 25 //Flags
noutram 0:3506f73fe611 26 volatile int switchONFlag=0;
noutram 0:3506f73fe611 27 volatile int switchOFFFlag=0;
noutram 0:3506f73fe611 28 volatile int tickerFlag = 0;
noutram 0:3506f73fe611 29
noutram 0:3506f73fe611 30 int main() {
noutram 0:3506f73fe611 31 //Setup switch interrupts
noutram 0:3506f73fe611 32 SWOn.rise(doSwitchON);
noutram 0:3506f73fe611 33 SWOff.rise(doSwitchOFF);
noutram 0:3506f73fe611 34
noutram 0:3506f73fe611 35 //Initial PWM state
noutram 0:3506f73fe611 36 pwmRed.period_us(T);
noutram 0:3506f73fe611 37 pwmRed.pulsewidth_us(Tmark);
noutram 0:3506f73fe611 38
noutram 0:3506f73fe611 39
noutram 0:3506f73fe611 40 printf("Ready\n");
noutram 0:3506f73fe611 41
noutram 0:3506f73fe611 42 while(1) {
noutram 0:3506f73fe611 43 sleep();
noutram 0:3506f73fe611 44
noutram 0:3506f73fe611 45 //Which interrupt occured?
noutram 0:3506f73fe611 46 if (switchONFlag == 1) {
noutram 0:3506f73fe611 47 switchONFlag = 0;
noutram 0:3506f73fe611 48 delta = 5;
noutram 0:3506f73fe611 49 t.attach(doTwinkle, 0.1);
noutram 0:3506f73fe611 50 printf("ON button pressed\n");
noutram 0:3506f73fe611 51 }
noutram 0:3506f73fe611 52 else if (switchOFFFlag == 1) {
noutram 0:3506f73fe611 53 switchOFFFlag = 0;
noutram 0:3506f73fe611 54 delta = -5;
noutram 0:3506f73fe611 55 t.attach(doTwinkle, 0.1);
noutram 0:3506f73fe611 56 printf("OFF button pressed\n");
noutram 0:3506f73fe611 57 }
noutram 0:3506f73fe611 58
noutram 0:3506f73fe611 59 //Has ticker hit the end stop?
noutram 0:3506f73fe611 60 if (tickerFlag == 1) {
noutram 0:3506f73fe611 61 tickerFlag = 0;
noutram 0:3506f73fe611 62 delta = 0; //Pedantic
noutram 0:3506f73fe611 63 t.detach(); //Turn off ticker
noutram 0:3506f73fe611 64 printf("Timer finished\n");
noutram 0:3506f73fe611 65 }
noutram 0:3506f73fe611 66 //Update PWM
noutram 0:3506f73fe611 67 pwmRed.pulsewidth_us(Tmark);
noutram 0:3506f73fe611 68
noutram 0:3506f73fe611 69 printf("Tmark = %d\n", Tmark); //Debug
noutram 0:3506f73fe611 70 }
noutram 0:3506f73fe611 71 }
noutram 0:3506f73fe611 72
noutram 0:3506f73fe611 73 void doSwitchON()
noutram 0:3506f73fe611 74 {
noutram 0:3506f73fe611 75 switchONFlag=1;
noutram 0:3506f73fe611 76 }
noutram 0:3506f73fe611 77
noutram 0:3506f73fe611 78 void doSwitchOFF()
noutram 0:3506f73fe611 79 {
noutram 0:3506f73fe611 80 switchOFFFlag=1;
noutram 0:3506f73fe611 81 }
noutram 0:3506f73fe611 82
noutram 0:3506f73fe611 83 //ISR for Timer
noutram 0:3506f73fe611 84 void doTwinkle()
noutram 0:3506f73fe611 85 {
noutram 0:3506f73fe611 86 //Add on delta
noutram 0:3506f73fe611 87 Tmark += delta;
noutram 0:3506f73fe611 88
noutram 0:3506f73fe611 89 //Cap at extremes
noutram 0:3506f73fe611 90 if (Tmark > 100) {
noutram 0:3506f73fe611 91 Tmark = 100;
noutram 0:3506f73fe611 92 }
noutram 0:3506f73fe611 93 else if (Tmark < 0) {
noutram 0:3506f73fe611 94 Tmark = 0;
noutram 0:3506f73fe611 95 }
noutram 0:3506f73fe611 96
noutram 0:3506f73fe611 97 //Check bounds
noutram 0:3506f73fe611 98 if ((Tmark == 100) || (Tmark == 0)) {
noutram 0:3506f73fe611 99 tickerFlag = 1;
noutram 0:3506f73fe611 100 }
noutram 0:3506f73fe611 101 }