Joseph Roberts

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9 years, 8 months ago.

Using an RtosTimer inside a class

I'm trying to use an RtosTimer within a class but the mbed locks up. I think this is because I'm calling threadHelper each tick and its creating a new pointer whereas I actually want to call threadMethod each tick or call threadHeper each tick but use the same pointer.

Can anyone show me how I should be doing this?

The code below works for an RtosThread because threadHelper is only called once, but I need to use an Rtos Timer.

    #ifndef TEST_CLASS_H
    #define TEST_CLASS_H
     
    #include "mbed.h"
    #include "rtos.h"
     
    /** TestClass class.
     *  Used for demonstrating stuff.
     */
    class TestClass
    {
    public:
        /** Create a TestClass object with the specified specifics
         *
         * @param led The LED pin.
         * @param flashRate The rate to flash the LED at in Hz.
         */
        TestClass(PinName led, float flashRate);
     
        /** Start flashing the LED using a Thread
         */
        void start();
     
    private:
        //Member variables
        DigitalOut m_Led;
        float m_FlashRate;
        RtosTimer *m_rtosTimer;
     
        //Internal methods
        static void threadHelper(const void* arg);
        void threadMethod();
    };
     
    #endif

    #include "TestClass.h"
     
    TestClass::TestClass(PinName led, float flashRate) : m_Led(led, 0), m_FlashRate(flashRate)
    {
        //NOTE: The RTOS hasn't started yet, so we can't create the internal thread here
    }
     
    void TestClass::start()
    {
        m_rtosTimer = new RtosTimer(&TestClass::threadHelper, osTimerPeriodic, (void *)0);
        int updateTime = (1.0 / m_FlashRate) * 1000;
        m_rtosTimer->start(updateTime);
    }
     
    void TestClass::threadHelper(const void* arg)
    {
        //Cast the argument to a TestClass instance pointer
        TestClass* instance = (TestClass*)arg;
     
        //Call the thread method for the TestClass instance
        instance ->threadMethod();
    }
     
    void TestClass::threadMethod()
    {
        //Do some stuff
    }

Thanks

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