University of Plymouth - Stages 1, 2 and 3 / Mbed OS Task330

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

main.cpp@0:397b84c74d17, 2017-10-23 (annotated)

Committer:
noutram
Date:
Mon Oct 23 09:37:46 2017 +0000
Revision:
0:397b84c74d17
Child:
1:e84a51c98d75
Managing 2 switches with rapid polling

Who changed what in which revision?

UserRevisionLine numberNew contents of line
noutram 0:397b84c74d17 1 #include "mbed.h"
noutram 0:397b84c74d17 2 #include "SWPoll.hpp"
noutram 0:397b84c74d17 3
noutram 0:397b84c74d17 4 #define N 1000000
noutram 0:397b84c74d17 5 #define RELEASED 0
noutram 0:397b84c74d17 6 #define PRESSED 1
noutram 0:397b84c74d17 7
noutram 0:397b84c74d17 8 //Function prototypes
noutram 0:397b84c74d17 9 void task1();
noutram 0:397b84c74d17 10 void task2();
noutram 0:397b84c74d17 11
noutram 0:397b84c74d17 12 //Hardware objects
noutram 0:397b84c74d17 13 DigitalOut red_led(PE_15); //CountUp is in its critical section
noutram 0:397b84c74d17 14 DigitalOut yellow_led(PB_10); //CountDown is in its critical section
noutram 0:397b84c74d17 15 DigitalOut green_led(PB_11); //counter != 0
noutram 0:397b84c74d17 16 DigitalOut onboardLED(LED1);
noutram 0:397b84c74d17 17
noutram 0:397b84c74d17 18 DigitalIn button(USER_BUTTON);
noutram 0:397b84c74d17 19 DigitalIn sw1(PE_12);
noutram 0:397b84c74d17 20 DigitalIn sw2(PE_14);
noutram 0:397b84c74d17 21
noutram 0:397b84c74d17 22 SWPoll switch1(sw1, red_led);
noutram 0:397b84c74d17 23 SWPoll switch2(sw2, green_led);
noutram 0:397b84c74d17 24
noutram 0:397b84c74d17 25
noutram 0:397b84c74d17 26
noutram 0:397b84c74d17 27 int main() {
noutram 0:397b84c74d17 28
noutram 0:397b84c74d17 29 //Main uses a Timer
noutram 0:397b84c74d17 30 yellow_led = 1;
noutram 0:397b84c74d17 31 Timer t;
noutram 0:397b84c74d17 32
noutram 0:397b84c74d17 33 //Now loop forever
noutram 0:397b84c74d17 34 t.start();
noutram 0:397b84c74d17 35 while(1) {
noutram 0:397b84c74d17 36 //Flash the yellow on the "main thread"
noutram 0:397b84c74d17 37 if (t.read_ms() >= 500) {
noutram 0:397b84c74d17 38 yellow_led = !yellow_led;
noutram 0:397b84c74d17 39 t.reset();
noutram 0:397b84c74d17 40 }
noutram 0:397b84c74d17 41 switch1.poll();
noutram 0:397b84c74d17 42 switch2.poll();
noutram 0:397b84c74d17 43
noutram 0:397b84c74d17 44 };
noutram 0:397b84c74d17 45 }
noutram 0:397b84c74d17 46
noutram 0:397b84c74d17 47
noutram 0:397b84c74d17 48 //Thread 1 - polling sw1 and controlling the red LED
noutram 0:397b84c74d17 49 void task1()
noutram 0:397b84c74d17 50 {
noutram 0:397b84c74d17 51 //Loop forever
noutram 0:397b84c74d17 52 while(1) {
noutram 0:397b84c74d17 53 //Spin on sw1
noutram 0:397b84c74d17 54 while (sw1 == RELEASED) {};
noutram 0:397b84c74d17 55 //Allow short delay for switch bounce
noutram 0:397b84c74d17 56 Thread::wait(200);
noutram 0:397b84c74d17 57 //Spin again on sw1
noutram 0:397b84c74d17 58 while (sw1 == PRESSED) {};
noutram 0:397b84c74d17 59 //Toggle LED
noutram 0:397b84c74d17 60 red_led = !red_led;
noutram 0:397b84c74d17 61 //Again, wait for switch bounce
noutram 0:397b84c74d17 62 Thread::wait(200);
noutram 0:397b84c74d17 63 }
noutram 0:397b84c74d17 64 }
noutram 0:397b84c74d17 65
noutram 0:397b84c74d17 66 //Thread 2 - polling sw2 and controlling the green LED
noutram 0:397b84c74d17 67 void task2()
noutram 0:397b84c74d17 68 {
noutram 0:397b84c74d17 69 //Loop forever
noutram 0:397b84c74d17 70 while(1) {
noutram 0:397b84c74d17 71 //Spin on sw2
noutram 0:397b84c74d17 72 while (sw2 == RELEASED) {};
noutram 0:397b84c74d17 73 //Allow short delay for switch bounce
noutram 0:397b84c74d17 74 Thread::wait(200);
noutram 0:397b84c74d17 75 //Spin again on sw2
noutram 0:397b84c74d17 76 while (sw2 == PRESSED) {};
noutram 0:397b84c74d17 77 //Toggle LED
noutram 0:397b84c74d17 78 green_led = !green_led;
noutram 0:397b84c74d17 79 //Again, wait for switch bounce
noutram 0:397b84c74d17 80 Thread::wait(200);
noutram 0:397b84c74d17 81 }
noutram 0:397b84c74d17 82 }