Dear all,Now, I have tried to measure the execution time of several modules.To measure exeuction time, I used the logic analyzer.But, I found some strange things.1. When I called Leds interface sequentially as below, I found that it took a time about 20us.call Leds.redOn();call Leds.redOff();But I found that it took a time about 2us when I called TOSH_SET and TOSh_CLR.TOSH_SET_RED_PIN();TOSH_CLR_RED_PIN();In my thought, it took much time since Leds interface used operating system.Why does two methods task a different elapsed time?
If you look at system/LedsC.nc and you will see it does more than just call TOSH_xxx.
2. When I call send ZigBee TX in OscilloscopeRF application, I found that it took a time about 4-8ms between call Send and event sendDone.There are two questions. 1) Why is the difference of transmission time large? 2) I think that it takes a long time to transmit packet about 4ms. If I want to synchronize two modules, I think that I must send packet for synchronization with short transmission time. Why is transmission time large?
The delay is a combination of the backoff timer and clear channel assessment.
Cory
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