I'm trying to connect a u-Blox USB GPS device to an embedded (armel) Linux 2.6.32 system based on BusyBox. The device has a native CDC ACM USB interface. The system didn't come with cdc_acm, so I cross-compiled it, transferred & insmodded it, and it loaded successfully (confirmed by
I plugged the device and it correctly got enumerated by the USB driver with address
001:003, and assigned to the
cdc_acm driver that created the
/dev/ttyACM0 file. However, opening the device with a serial terminal or even with the
cat command, results in garbage being printed, whereas ASCII NMEA commands should be printed (this is confirmed to work on two other systems).
stty runs on the file without errors (however the reported data is obviously invalid/arbitrary, due to the device being a USB device and not a serial device).
lsusb -v -s 1:3 also reports the correct information for the device.
I don't know how to further debug the issue. What steps can I take to figure out the problem and solve it?