sniffing a laser tape

Question

First time using the sniffer. 
 I want to sniff out the communication for a laser tape measuring device (Boosch GLM 50C) 
 
 I noticed that I am unable to sniff out anything when using with an android phone (is it because of a pairing operation?) I did get some information in packets when using an iphone, but after the initial connection, I can only see the advertisement packets (when not connected).. 
 Can't it be done? 
 Wireshark log
 bosch.pcapng 
 CONNECT_REQ recieved
 bosch_2_.pcapng

endnode · Accepted Answer

Second sniffer log is perfectly fine except there are no real measurement data exchanges. But you now have working set-up, it seems that devices are not using any security (at least not at this point) as all GATT methods visible in the log are in clear. I assume that measurement protocol will run as Notify or Read methods over one of dedicated proprietary Characteristic Value handles. Unpair the device from phone (if paired), erase BT cache on the phone if possible and try to capture very first encounter of these two devices (e.g. restart both to be sure you start form clear situation). And try to capture actual data exchange (but the rest is on you, I don't think you want us to reverse the protocol for you, do you?:)

sniffing a laser tape

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