Read track via USB

gpsbabel -t -w  -i m241 -f /dev/ttyUSB0 -o gpx -F test.gpx

Read track via Bluetooth

Find mac:

hcitool scan
Scanning ...
 00:1B:C1:05:XX:XX    HOLUX_M-241

Bind to a serial port in /etc/bluetooth/rfcomm.conf

rfcomm4 {
 bind yes;
 device 00:1B:C1:05:XX:XX;
 channel 1;
 comment "Serial Port";
}

Connect the serial port:

rfcomm connect 4

read track:

gpsbabel -t -w  -i m241 -f /dev/rfcomm4 -o gpx -F test.gpx