Bluetooth Low Energy Swiss-army knife or Btlejack is a small software client designed to be used with the BBC Micro:Bit mini PC and can be used with one or more devices running a dedicated firmware. Once installed you will be able to sniff, jam and hijack Bluetooth Low Energy devices. Current version of this tool (2.0) supports BLE 4.x and 5.x.
“Btlejack relies on one or more BBC Micro:Bit. devices running a dedicated firmware. You may also want to use an Adafruit’s Bluefruit LE sniffer or a nRF51822 Eval Kit, as we added support for these devices. The BLE 5.x support is limited, as it does only support the 1Mbps Uncoded PHY and does not support channel map updates.”
“You need a UNIX based system (for example a Raspberry Pi). If you use the BBC Micro:Bit, you will need one to three Micro:Bit devices (three devices recommended) and for each device one free USB port. The power consumption of a Micro:Bit is rather low, so you can use a single USB port and a passive hub for powering the three recommended units.”
More details on Btlejack jump over to the GitHub website where it is now available to download and install. If you connect 3 microbits at the same time on your computer, Btlejack will be able to sniff on every advertising channel and has far more chance to capture the connection request.