Nicholas Outram / Mbed OS Task632-mbedos54

Demonstration of a message queue + memory pool

Fork of Task632-mbedos54 by Stage-1 Students SoCEM

main.cpp@10:3a3d2a571c8f, 2016-03-22 (annotated)

Committer:
noutram
Date:
Tue Mar 22 13:40:05 2016 +0000
Revision:
10:3a3d2a571c8f
Parent:
9:31031bbb59c7
Child:
11:6cfaf7dfecb9
Example of a memory pool + message queue

Who changed what in which revision?

UserRevisionLine numberNew contents of line
noutram 0:f916cefba2f4 1 #include "mbed.h"
noutram 0:f916cefba2f4 2 #include "rtos.h"
noutram 2:70084af839d3 3 #include "string.h"
noutram 2:70084af839d3 4 #include <stdio.h>
noutram 2:70084af839d3 5 #include <ctype.h>
noutram 0:f916cefba2f4 6
noutram 8:c5663f5fa848 7 #define SWITCH1_RELEASE 1
noutram 8:c5663f5fa848 8
noutram 8:c5663f5fa848 9 void thread1( const void* );
noutram 8:c5663f5fa848 10 void thread2( const void* );
noutram 8:c5663f5fa848 11 void switchISR();
noutram 0:f916cefba2f4 12
noutram 9:31031bbb59c7 13 //Analogue inputs
noutram 9:31031bbb59c7 14 AnalogIn adcIn(A0);
noutram 9:31031bbb59c7 15
noutram 0:f916cefba2f4 16 //Digital outputs
noutram 0:f916cefba2f4 17 DigitalOut onBoardLED(LED1);
noutram 0:f916cefba2f4 18 DigitalOut redLED(D7);
noutram 0:f916cefba2f4 19 DigitalOut yellowLED(D6);
noutram 0:f916cefba2f4 20 DigitalOut greenLED(D5);
noutram 0:f916cefba2f4 21
noutram 0:f916cefba2f4 22 //Digital inputs
noutram 0:f916cefba2f4 23 DigitalIn onBoardSwitch(USER_BUTTON);
noutram 8:c5663f5fa848 24 DigitalIn sw1(D4); //CONSIDER CHANGING THIS TO AN INTERRUPT
noutram 8:c5663f5fa848 25 DigitalIn sw2(D3);
noutram 8:c5663f5fa848 26
noutram 8:c5663f5fa848 27 //Threads
noutram 8:c5663f5fa848 28 Thread *t1;
noutram 0:f916cefba2f4 29
noutram 10:3a3d2a571c8f 30 //Class type
noutram 10:3a3d2a571c8f 31 class message_t {
noutram 10:3a3d2a571c8f 32 public:
noutram 10:3a3d2a571c8f 33 float adcValue;
noutram 10:3a3d2a571c8f 34 int sw1State;
noutram 10:3a3d2a571c8f 35 int sw2State;
noutram 10:3a3d2a571c8f 36
noutram 10:3a3d2a571c8f 37 //Constructor
noutram 10:3a3d2a571c8f 38 message_t(float f, int s1, int s2) {
noutram 10:3a3d2a571c8f 39 adcValue = f;
noutram 10:3a3d2a571c8f 40 sw1State = s1;
noutram 10:3a3d2a571c8f 41 sw2State = s2;
noutram 10:3a3d2a571c8f 42 }
noutram 10:3a3d2a571c8f 43 };
noutram 10:3a3d2a571c8f 44
noutram 10:3a3d2a571c8f 45 //Memory Pool - with capacity for 16 message_t types
noutram 10:3a3d2a571c8f 46 MemoryPool<message_t, 16> mpool;
noutram 0:f916cefba2f4 47
noutram 10:3a3d2a571c8f 48 //Message queue - matched to the memory pool
noutram 10:3a3d2a571c8f 49 Queue<message_t, 16> queue;
noutram 8:c5663f5fa848 50
noutram 9:31031bbb59c7 51 // Call this on precise intervals
noutram 9:31031bbb59c7 52 void adcISR() {
noutram 9:31031bbb59c7 53
noutram 10:3a3d2a571c8f 54 //Read sample - make a copy
noutram 10:3a3d2a571c8f 55 float sample = adcIn;
noutram 10:3a3d2a571c8f 56 //Grab switch state
noutram 10:3a3d2a571c8f 57 uint32_t switch1State = sw1;
noutram 10:3a3d2a571c8f 58 uint32_t switch2State = sw2;
noutram 9:31031bbb59c7 59
noutram 10:3a3d2a571c8f 60 //Allocate a block from the memory pool
noutram 10:3a3d2a571c8f 61 message_t *message = mpool.alloc();
noutram 10:3a3d2a571c8f 62 if (message == NULL) {
noutram 10:3a3d2a571c8f 63 //Out of memory
noutram 10:3a3d2a571c8f 64 redLED = 1;
noutram 10:3a3d2a571c8f 65 return;
noutram 10:3a3d2a571c8f 66 }
noutram 10:3a3d2a571c8f 67
noutram 10:3a3d2a571c8f 68 //Fill in the data
noutram 10:3a3d2a571c8f 69 message->adcValue = sample;
noutram 10:3a3d2a571c8f 70 message->sw1State = switch1State;
noutram 10:3a3d2a571c8f 71 message->sw2State = switch2State;
noutram 9:31031bbb59c7 72
noutram 9:31031bbb59c7 73 //Write to queue
noutram 10:3a3d2a571c8f 74 osStatus stat = queue.put(message); //Note we are sending the "pointer"
noutram 9:31031bbb59c7 75
noutram 9:31031bbb59c7 76 //Check if succesful
noutram 9:31031bbb59c7 77 if (stat == osErrorResource) {
noutram 9:31031bbb59c7 78 redLED = 1;
noutram 9:31031bbb59c7 79 printf("queue->put() Error code: %4Xh, Resource not available\r\n", stat);
noutram 10:3a3d2a571c8f 80 mpool.free(message);
noutram 10:3a3d2a571c8f 81 return;
noutram 9:31031bbb59c7 82 }
noutram 8:c5663f5fa848 83 }
noutram 8:c5663f5fa848 84
noutram 9:31031bbb59c7 85 //Normal priority thread (consumer)
noutram 4:dae8898e55fe 86 void thread1( const void* arg )
noutram 10:3a3d2a571c8f 87 {
noutram 4:dae8898e55fe 88 while (true) {
noutram 10:3a3d2a571c8f 89 //Block on the queue
noutram 10:3a3d2a571c8f 90 osEvent evt = queue.get();
noutram 9:31031bbb59c7 91
noutram 10:3a3d2a571c8f 92 //Check status
noutram 10:3a3d2a571c8f 93 if (evt.status == osEventMessage) {
noutram 10:3a3d2a571c8f 94 message_t *pMessage = (message_t*)evt.value.p; //This is the pointer (address)
noutram 10:3a3d2a571c8f 95 //Make a copy
noutram 10:3a3d2a571c8f 96 message_t msg(pMessage->adcValue, pMessage->sw1State, pMessage->sw2State);
noutram 10:3a3d2a571c8f 97 //We are done with this, so give back the memory to the pool
noutram 10:3a3d2a571c8f 98 mpool.free(pMessage);
noutram 10:3a3d2a571c8f 99
noutram 10:3a3d2a571c8f 100 //Echo to the terminal
noutram 10:3a3d2a571c8f 101 printf("ADC Value: %.2f\t", msg.adcValue);
noutram 10:3a3d2a571c8f 102 printf("SW1: %u\t", msg.sw1State);
noutram 10:3a3d2a571c8f 103 printf("SW2: %u\n\r", msg.sw2State);
noutram 9:31031bbb59c7 104 }
noutram 10:3a3d2a571c8f 105
noutram 10:3a3d2a571c8f 106
noutram 9:31031bbb59c7 107 } //end while
noutram 0:f916cefba2f4 108 }
noutram 0:f916cefba2f4 109
noutram 4:dae8898e55fe 110
noutram 8:c5663f5fa848 111 // Main thread
noutram 0:f916cefba2f4 112 int main() {
noutram 0:f916cefba2f4 113 redLED = 0;
noutram 0:f916cefba2f4 114 yellowLED = 0;
noutram 2:70084af839d3 115 greenLED = 0;
noutram 8:c5663f5fa848 116
noutram 9:31031bbb59c7 117 //Start message
noutram 10:3a3d2a571c8f 118 printf("Welcome\n");
noutram 10:3a3d2a571c8f 119
noutram 9:31031bbb59c7 120 //Hook up timer interrupt
noutram 9:31031bbb59c7 121 Ticker timer;
noutram 10:3a3d2a571c8f 122 timer.attach(&adcISR, 0.1);
noutram 9:31031bbb59c7 123
noutram 8:c5663f5fa848 124 //Threads
noutram 9:31031bbb59c7 125 t1 = new Thread(&thread1);
noutram 7:cd015e83995a 126
noutram 9:31031bbb59c7 127 printf("Main Thread\n");
noutram 2:70084af839d3 128 while (true) {
noutram 9:31031bbb59c7 129 Thread::wait(5000);
noutram 9:31031bbb59c7 130 puts("Main Thread Alive");
noutram 0:f916cefba2f4 131 }
noutram 0:f916cefba2f4 132 }
noutram 2:70084af839d3 133
noutram 2:70084af839d3 134