Hi ! I want to have a function in my program be called every full second. i mean, it should be called whenever the RTC of the PC rolls over one second. how do i do that ? if i use alarm or setitimer, this goes independently from the RTC, as as far as i understand ? Do I need to poll the rtc for recognizing the change of the SECOND field ? another question: I want to communicate to a microcontroller via serial port, which shall aquire data (Power/Energy Measurement) What is the best strategy for communicating ? I mean, i have the problem to syncronize the microcontroller(which has no RTC) to the RTC of the PC. i.e. every second my program should get a value from the controller. But the problem for me is: if i trigger the microcontroller from my program under Linux, i think it is not guaranteed that the distance between the trigger signals will be equal, because we are in a multitasking environment. maybe the PC is busy and no trigger will arrive to the microcontroller and so the measurement will get wrong.... any suggestions ? regards Roland
