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Dear BCM
We found out one serious issue that, BCM20736 work in master/slave mode
Work in Master, it has it's connection event of Anchor point, here we call it Anchor_point_1
Work in slave, its master has the connection event of Anchor point, here we call it Anchor_point_2
At the beginning, the Anchor_point_1 and Anchor_point_2 is far apart, about over 6~7 ms. and the data transmit between this BCM20736 and its master is right.
But due to the crystal accuracy(10PPM) or other influence, the Anchor_point_1 & Anchor_point_2 might shift left or right and the two might be closer and closer. We checked in our test that, in one 30ms interval, the Anchor_point_1 & Anchor_point_1 would be 250ns closer to each other. In such conditions, Anchor_point_1 & Anchor_point_1 would continue closer until be overlap, and the data transmition would be error when Anchor_point_1 and Anchor_point_2 as close as +/- 2ms.
Though the connection would not break down (because we set the timer out as long as 5s), but in fact, the data is hard to be transmitted between this BCM20736 and its master.
Of cause that, the data transmition would get right after Anchor_point_1 & Anchor_point_2 apart over 2ms. but it would take nearly 10 minutes, and it would happen again after several hours.
How to solve this issue ?? or is there any good suggestion about this ???
Many thanks...
Solved! Go to Solution.
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Leman,
This is expected behavior because two connections cannot be scheduled at the same instant (including any overlap and scheduling time). The Bluetooth scheduler in the FW will try to schedule connection events in a mostly round-robin based on the amount of data and supervision timeouts. At same time, it will try to nudge its slave away from its master by deliberately moving its clock at a faster rate than the drift so the overlap time is shortened, but the amount per connection interval is limited because large changes will cause the slave to get out of sync very quickly.