Timer callbacks execute in the timer service task, which is scheduled just like any other task. Do you have the priority of the task set higher than the application tasks so it runs immediately? I rejoiced too soon. I use the xTimerResetFromISR() function in my interrupt subroutine for restarting my software timer. After a start of device it looks like good, but if I use this function again the time between call of the xTimerResetFromISR() and the first triggering of the software timer differ times from time. I use the portENDSWITCHINGISR(false) function in the end of the interrupt subroutine. Too much time between xSemaphoreGiveFromISR and xSemaphoreTake() Sent from sourceforge.net because you indicated interest in https://sourceforge.net/p/freertos/discussion/382005/ To unsubscribe from further messages, please visit https://sourceforge.net/auth/subscriptions/