University of Plymouth - Stages 1, 2 and 3 / Mbed OS Task622-mbedos-FZ429ZI

Demonstrating a ISR signalling a high-priority thread

Dependencies:   ELEC350-Practicals-FZ429

Fork of Task622Solution-mbedos54 by Nicholas Outram

main.cpp@11:9dcbcda8ea12, 2017-11-14 (annotated)

Committer:
noutram
Date:
Tue Nov 14 14:22:03 2017 +0000
Revision:
11:9dcbcda8ea12
Parent:
10:730250526509 
Streamlined version

Who changed what in which revision?

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noutram 0:f916cefba2f4 1 #include "mbed.h"
noutram 10:730250526509 2 #include <iostream>
noutram 10:730250526509 3 #include "sample_hardware.hpp"
noutram 10:730250526509 4
noutram 2:70084af839d3 5 #include "string.h"
noutram 2:70084af839d3 6 #include <stdio.h>
noutram 2:70084af839d3 7 #include <ctype.h>
noutram 0:f916cefba2f4 8
noutram 8:b28defacd894 9 #define SWITCH1_RELEASE 1
noutram 8:b28defacd894 10
noutram 9:c46e831f8e4a 11 void thread1();
noutram 9:c46e831f8e4a 12 void thread2();
noutram 8:b28defacd894 13 void switchISR();
noutram 0:f916cefba2f4 14
noutram 10:730250526509 15 InterruptIn sw(PE_12);
noutram 8:b28defacd894 16
noutram 8:b28defacd894 17 //Threads
noutram 10:730250526509 18 Thread t1(osPriorityRealtime); //Higher priority
noutram 10:730250526509 19 Thread t2(osPriorityNormal);
noutram 0:f916cefba2f4 20
noutram 8:b28defacd894 21
noutram 8:b28defacd894 22 //Called on the falling edge of a switch
noutram 8:b28defacd894 23 void switchISR() {
noutram 10:730250526509 24 t1.signal_set(SWITCH1_RELEASE); //Very short
noutram 8:b28defacd894 25 }
noutram 8:b28defacd894 26
noutram 8:b28defacd894 27 //High priority thread
noutram 9:c46e831f8e4a 28 void thread1()
noutram 4:dae8898e55fe 29 {
noutram 8:b28defacd894 30 redLED = 1;
noutram 4:dae8898e55fe 31 while (true) {
noutram 11:9dcbcda8ea12 32 //Block (WAITING) for signal from the ISR
noutram 8:b28defacd894 33 Thread::signal_wait(SWITCH1_RELEASE);
noutram 11:9dcbcda8ea12 34
noutram 11:9dcbcda8ea12 35 //Flash LED
noutram 8:b28defacd894 36 redLED = !redLED;
noutram 11:9dcbcda8ea12 37
noutram 11:9dcbcda8ea12 38 //Wait for switch bounce to settle
noutram 10:730250526509 39 Thread::wait(200);
noutram 10:730250526509 40
noutram 10:730250526509 41 //Block using BUSY-WAIT
noutram 10:730250526509 42 // Timer t;
noutram 10:730250526509 43 // t.start();
noutram 10:730250526509 44 // while (t < 2);
noutram 10:730250526509 45
noutram 11:9dcbcda8ea12 46 //Clear any additional signals (caused by switch bounce and ISR)
noutram 10:730250526509 47 t1.signal_clr(SWITCH1_RELEASE); //Debounce - clear pending signals
noutram 4:dae8898e55fe 48 }
noutram 2:70084af839d3 49 }
noutram 2:70084af839d3 50
noutram 8:b28defacd894 51 //This thread has normal priority
noutram 9:c46e831f8e4a 52 void thread2()
noutram 0:f916cefba2f4 53 {
noutram 8:b28defacd894 54 greenLED = 1;
noutram 10:730250526509 55 while (true) {
noutram 10:730250526509 56 Thread::wait(500); // WAIT FOR 0.5 SECONDS - spinning
noutram 8:b28defacd894 57 greenLED = !greenLED;
noutram 6:2e463846b575 58 }
noutram 0:f916cefba2f4 59 }
noutram 0:f916cefba2f4 60
noutram 4:dae8898e55fe 61
noutram 8:b28defacd894 62 // Main thread
noutram 0:f916cefba2f4 63 int main() {
noutram 10:730250526509 64
noutram 10:730250526509 65 //Power on self-test
noutram 10:730250526509 66 post();
noutram 10:730250526509 67
noutram 10:730250526509 68 //Start Threads
noutram 10:730250526509 69 t1.start(thread1);
noutram 10:730250526509 70 t2.start(thread2);
noutram 7:cd015e83995a 71
noutram 8:b28defacd894 72 //Hook up interrupt
noutram 10:730250526509 73 sw.fall(switchISR);
noutram 8:b28defacd894 74
noutram 10:730250526509 75 printf("Main Thread\n");
noutram 2:70084af839d3 76 while (true) {
noutram 4:dae8898e55fe 77 Thread::wait(osWaitForever);
noutram 0:f916cefba2f4 78 }
noutram 0:f916cefba2f4 79
noutram 0:f916cefba2f4 80 }
noutram 2:70084af839d3 81
noutram 2:70084af839d3 82