USB serial monitor

uscmon is serial port sniffer for USB serial converters, like FTDI. For now, only FTDI is supported.

Following events are supported:

• data transfers
• baud rate changing
• parity, data, stop bits changing
• flow control changing
• DTR/DSR, RTS/CTS, RI events
• break, overrun/parity/frame error events

Build

$ qmake uscmon.pro
$ make

To clean up:

$ make clean
$ make distclean

Setup

Make sure, debug_fs is enabled and usbmon module is loaded. Read usbmon info for more information.

# modprobe usbmon
# mount | grep debugfs
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
# ls -l /sys/kernel/debug/usb/usbmon/
<should be non-empty>

Usage

sudo ./uscmon

For uscmon to detect the USB device, it must be re-plugged while uscmon is running. A successful detection should look like this:

$ sudo ./uscmon
USB serial converter monitor
new device found: 14:7 0403:6001 FT232R USB UART, FTDI, serial: AL0249S3

A debug session output of uscmon might look like this:

Parity: NONE, 8 data bits,  1 stop bits
DTR ON
RTS ON
Flow control: software
Baudrate set: 115200
Baudrate set: 1200
RTS ON
DTR OFF
Parity: NONE, 8 data bits,  1 stop bits
DTR OFF
Flow control: software
Baudrate set: 1200
RTS ON
DTR ON
Parity: NONE, 8 data bits,  1 stop bits
DTR ON
Flow control: software
DTR ON
403:6001 Data out (7)
07 42 a0 00 05 40 d2
403:6001 Data out (7)
07 42 a0 00 05 40 d2
403:6001 Data out (7)
07 42 a0 00 05 40 d2
DTR OFF
DTR OFF
RTS OFF
Parity: NONE, 8 data bits,  1 stop bits
[...]