Connect to BLE device with gatttool in non-interactive mode

Question

I'm trying to read data from my weight scale Bluetooth Low Energy device. After the measurement, the scale advertise new data via bluetooth for about a minute. I can read it using gatttool like that:

gatttool -b MAC_ADDRESS -I
connect

The -I option runs the gatttool in interactive mode. Then, after successfull connection I got data like this:

Indication   handle = 0x0012 value: 02 9c 0e e4 07 08 1c 0b 02 0f 
Indication   handle = 0x0012 value: 02 68 0b e4 07 08 1c 0c 03 06 
Indication   handle = 0x0012 value: 02 18 47 e4 07 08 1f 07 11 3a

I can read the value from this fine but I need to do this in gatttool non-interactive mode, so I can read the output of that in my Qt app with QProcess class. gatttool -h doesn't say much about how to just connect with the device. There is no command like: gatttool -b MAC_ADDRESS connect. There are commands to read or write but I don't need this. I just want to connect and wait for the upcoming data from the device. Can anyone tell me how to connect in non-interactive mode using gatttool?

Thanks.

Answer 1

gatttool is one of the eight tools that have been deprecated by the BlueZ project.

Wouldn't you be better off handling the BLE notification directly in Qt?

e.g: https://doc.qt.io/archives/qt-5.7/qtbluetooth-heartlistener-example.html