As we want to synchronize our slave clocks using the XBee modules, we wanted to know what could be the difference in the reception dates between two slaves when the master clock broadcasts a “clock sync” message.
So I wrote a little bit code which toggled a GPIO when the message “clock sync” (0xAA) is received. The master firmware would emit 0xAA at 2Hz.
Then, I used a logic analyzer to observe the time difference between the two GPIO blinks.
I found a mean difference of 60µs with a standard deviation of 55µs. I’ll let Issam & JB conclude (because they have far more knowledge in the localization part than me) but from my point of view, it seems to be fine.