NRF Snifffer 1.0.1 problem

[MAX]

Hi,

I am using ble-sniffer_nRF51822_1.0.1_1111_Sniffer.hex as the sniffer and I am trying to see all ble beacons. Because I have many beacons about (100 in one second) I decided to set the ble becons to transmit on one channel. 30 PCs transmit on channel 37. 30 PCs transmit on channel 38. 40 PCs transmit on channel 39.

When all beacons(channel 37,38 and 39) are in the read range of the sniffer, the sniffer will send me the packet over the serial. But when there are just one channel beacons for example only channel 37 beacons are in the read range of sniffer. in this case, the sniffer will not send me any packet and I just get the ping data from serial. When I put one beacon of channel 38 and one beacon of channel 39 then I will get all beacons packet. It seems that the sniffer works when it sees data on all 3 channels.

Is this the sniffer firmware bug? What should I do?

[Hung Bui]

Hi Max,

This is because the sniffer can't listen to all 3 channels at the same time (simply because it has only one radio). So it must use a hopping pattern. By default the hopping is 37 38 39. You can change that to set to only one channel, 37 for example.

Note that even though your beacons transmit on different channel, if they transmit at the same time and if they are close enough (signal strength strong enough) to the receiver they will still cause interference.

[MAX]

Hi Hung,

Thank you for your reply. You are right, But my problem is that the sniffer will be paused on the empty channel. When I am using all beacons on channel 37, the sniffer will not see any thing. I think the problem is that the sniffer will stay in channel 38 because it is empty and no beacons transmit on this channel. (Is this the firmware bug?)

How can I tell the sniffer to listen on only one channel?