How to scan Bluetooth devices

1. Scan for available Bluetooth devices

 hcitool scan
Scanning ...
       A0:AF:BD:3B:26:61       lmecxl0923
       B0:55:08:40:33:84       HUAWEI P8 lite 2017

2. Setting the device to Visible

To control the visiblity of our Bluetooth device to other Bluetooth hardware.

• to enable visibility:

 hciconfig hciX piscan

(hciX corresponds to the available Bluetooth hardware: hci0)

• To disable visibility:

 hciconfig hciX noscan

(hciX corresponds to the available Bluetooth hardware: hci0)

3. How to scan via bluetoothd/systemd

Systemd provides a tool for Bluetooth management: bluetoothctl.
Example session with bluetoothclt for scanning, pairing, connecting:

 bluetoothctl
[NEW] Controller 43:43:A1:12:1F:AC stm32mp1 [default]
Agent registered
[bluetooth]# power on
Changing power on succeeded
[CHG] Controller 43:43:A1:12:1F:AC Powered: yes
[bluetooth]# agent on
Agent is already registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 43:43:A1:12:1F:AC Discovering: yes
[NEW] Device D8:DB:36:D1:39:88 STM
...
[bluetooth]# scan off
[CHG] Controller 43:43:A1:12:1F:AC Discovering: no
Discovery stopped
[bluetooth]#pair D8:DB:36:D1:39:88
Pairing successful
[bluetooth]# connect D8:DB:36:D1:39:88
Connection successful
[STM]# quit
Agent unregistered
[DEL] Controller 43:43:A1:12:1F:AC stm32mp1 [default]

GPIO alternate function

System Trace Module

GPIO alternate function

System Trace Module

General-Purpose Input/Output (A realization of open ended transmission between devices on an embedded level. These pins available on a processor can be programmed to be used to either accept input or provide output to external devices depending on user desires and applications requirements.)