question and how-to use kali to find out communication between iot devices

[aardbewoner]

Hello old grumpy man here who is trying to find out how to fing out what the use like wifi or bluetooth .I now my bfh-155 denver brand watch is using bluetooth and sadly on a smrtphone without internet,so this is the only watch that do works for 90%. My led controller is no idea. and i have no idea how to find that out. Yes i do read but soon get lost in what to use and/or where to get it. So my asking is is there a kind of for dummies guide on this subjects ? I grow more frustrated every day every thing need a smartphon and windows desktop but the never say what version it need. got android 4,4 and windows 2000
Greetings Jan

[Fred Sheehan]

Any device connected to a network will send data to and from the access point (i.e. a home router say, if you have one)

To find out what is being sent back and forth, you need a wireless card that can be used in 'promiscuous' mode, and like it sounds, this means it will accept all data being sent over the local network, not just the data being sent to it specifically, which is the default.

If you have such a network adapter that can capture all data sent, you can then use the wireshark application in Kali to view the data being sent.

Interpreting the captured data is a whole other ballgame;

https://www.wireshark.org/docs/wsug_html/