Issuing modem commands to an unrooted Android device

Did you know that Android devices expose a modem on the USB interface, even when "Tethering" is turned off? It appears like this in dmesg:

[22338.529851] cdc_acm 1-3:1.1: ttyACM0: USB ACM device

You can connect to this as a raw serial console like:

screen /dev/ttyACM0


minicom -D /dev/ttyACM0

This will accept GSM modem commands prefixed with AT, and give information about the phone, and presumably allow a dialup-like interface.

Many of the examples on will work with the phone, depending on which manufacturer and capability set, presumably. With my Samsung Galaxy XCover 4, I got the GSM capability set.

Try playing around with this, but don't get charged by your provider too much for making calls you never end! Make sure you hang up properly as per the protocol.

For more on standard modem commands, see the Hayes command set article on Wikipedia.

That's all for now!


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