Using the nRF51-multi-role-conn-observer-advertiser-master project to test timeslotting I have encountered two issues (Softdevice s110 7.1)
Issue #1: Repetition of advertisement We use the default interval in the code (100ms - 150ms). We should see a packet advertised on each of the channels (37, 38, 39) every ~100ms. What we observe is the advertisement on each channel (37, 38, 39) and shortly after (~ 1-2ms) another advertisement cycle occurs on all 3 channels. This cycle could repeat several times.
In debugging I discovered the problem is the application is receiving a NRF_EVT_RADIO_BLOCKED event from the softdevice. After the event is received the application will abort the time slot order and request the next earliest timeslot.
My question is: Is there a reason the application requests the next earliest timeslot? Could the application be changed to request a timeslot farther out (example 100ms interval, request timeslot 150ms later).
I have tried modifying the application code to request a timeslot later but doesn't work.
Issue #2 Non-advertisement channels broadcasting data Using the spectrum analyzer we observe communication on non advertisement channels. We used the channel mask to select only one advertisement channel at a time. When a channel is selected we see data being broadcasted on a non-advertisement frequency
Ch 39 (2.480 MHz) : We see transmission on 2.480 MHz but also see transmission on 2.414 MHz (Ch 5)
Ch 37 (2.402 MHz): We see transmission on 2.402 MHz but also see transmission on 2.432 MHz (Ch 13)
Ch 38 (2.426 MHz): We see transmission on 2.426 MHz but also see transmission on 2.456 MHz (Ch 25)
If all the channels are disabled we don't see any transmission on the BTLE band.
I have not been able to root cause this issue.
