Dear all,

Currently I am using the LowPowerTicker to tick my STM32L031K6 MCU. However, the ticker froze after around 72 minutes from reset. So I use the same code but replace the LowPowerTicker with Ticker and it works fine (tested for 3 hours).

In fact, I have come across same issue with Ticker when I first used Mbed in 2014. It is because a variable was overflowed after 72 minutes and was not handled properly. The same issue on Ticker was addressed in the next released mbed library.

I believe this issue on LowPowerTicker is the same as that on Ticker. A variable was overflowed but not handled properly.

Hope such issue can be addressed in the near future.

Thanks a lot.

Hi, i'm facing the same issue with my STM32L073RZ NUCLEO board is there a workaround for solving this?

I used InterruptIn to wake up my MCU instead of LowPowerTicker, and it works fine.

If you could use LowPowerTimeout instead of LowPowerTicker, you may try this. Note that I am using mbed-lib revision 159 (not release version).

#include "mbed.h"

bool time_out = false;
LowPowerTimeout* lp_timeout = new LowPowerTimeout();

void timeoutCallback()
{
    time_out = true;
}

int main()
{
    lp_timeout->attach(&timeoutCallback, 1.0);

    while(1)
    {
        if(time_out)
        {
            time_out = false;
            delete lp_timeout;
            lp_timeout = new LowPowerTimeout();
            lp_timeout->attach(&timeoutCallback, 1.0);
        }

        sleep();
    }
}

#include "mbed.h"

bool time_out = false;
LowPowerTimeout* lp_timeout = new LowPowerTimeout();

void timeoutCallback()
{
    time_out = true;
}

int main()
{
    lp_timeout->attach(&timeoutCallback, 1.0);

    while(1)
    {
        if(time_out)
        {
            time_out = false;
            delete lp_timeout;
            lp_timeout = new LowPowerTimeout();
            lp_timeout->attach(&timeoutCallback, 1.0);
        }

        sleep();
    }
}

Hi Tony, thanks for the tip. I tried this but without luck, the LowPowerTimeout still hangs after 72 minutes. In fact i am deleting and creating the object and attaching it every time the callback change the flag. Also, i used mbed-lib revision 159 but did not find any change in it that let me think it can solve the problem.

#include "mbed.h"

bool time_out = false;
LowPowerTimeout* lp_timeout = new LowPowerTimeout();

void timeoutCallback()
{
    time_out = true;
}

int main()
{
    lp_timeout->attach(&timeoutCallback, 1.0);

    while(1)
    {
        if(time_out)
        {
            time_out = false;
            delete lp_timeout;
            lp_timeout = new LowPowerTimeout();
            lp_timeout->attach(&timeoutCallback, 1.0);
        }

        sleep();
    }
}

Did you try the above program? My STM32L031K6 works fine for 2 hours. The reason why I used revision 159 is because my custom PCB used PA_9 and PA_10 as serial port, which is no longer available since revision 161.