I use KW38 to make a multiple connections, which is a combination of one central and four peripherals. Now, the central device should share the clock to the four peripherals to keep them in sync. The synchronization accuracy can not more than 2ms. And my current approach is as follow:
First, set the connection interval as 7.5ms. The central device get the systick of itself and send it to each peripherals with a writable characteristic. When a peripherals gets the systick, the delay on air should be taken into account. The key issue is that the delay on air seems to vary with signal strength. I use an oscilloscope to observe the time interval between the central send timestamp and the peripheral receive timestamp, and the result shows the time interval is between about 1.25ms and 15ms. Hence, I can not make a accurately synchronization.
Is there any better way to achieve my needs?
Thank you all very much!
