On Jun 15, 2008, at 11:49 PM, Tiny User wrote: > > Hello all, > > In a lecture for Philipp Levis at Stanford university > (http://www.youtube.com/watch?v=j6hRsue5b30 > ) he said that the time to post and run a task in tinyos needs 80 > cycles (10 micro sec). please any one knows how we can calculate or > measure these times?
There are two ways. The first is to read a counter register before and after a post() and in the scheduler loop for a null task, and add these two numbers. The other is to run an application with no interrupts (no radio, no timers) that just runs a self-posting task many times (through an increment variable). Have it send a byte to the UART when it starts and when it ends, and record the time between the bytes on a PC. If you run the task enough times (i.e., it takes several seconds), the error caused by jitter on the PC will be negligible. Phil _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
