I need to deal with two pieces of custom hardware which both send debugging data over two serial connections. Those serial connections go through two serial-to-USB converters. The serial-to-USB devices have the same vendor numbers, device numbers, and, apparently, the same serial numbers.
Here's the issue: I want to log the two serial ports separately. The custom hardware needs to be rebooted constantly, and whether they attach to the same /dev/ttyUSB* is completely random. How can I make them pick the same device path every time? I could make it dependent on what port it is plugged into, but that seems kind of hacky.
So, I ran a diff against the output of udevadm, like so:
$ udevadm info -a -p `udevadm info -q path -n /dev/ttyUSB1` > usb1
$ udevadm info -a -p `udevadm info -q path -n /dev/ttyUSB2` > usb2
$ diff usb1 usb2
The output of the diff is long; you can see it here
Grepping for serial (same for both):
$ udevadm info -a -p `udevadm info -q path -n /dev/ttyUSB2` | grep serial
SUBSYSTEMS=="usb-serial"
ATTRS{serial}=="0001"
ATTRS{serial}=="0000:00:1d.7"
Other info:
I'm using PuTTY to read from the serial ports.
OS:
$ uname -a
Linux xxxxxxxx.localdomain 2.6.32-279.14.1.el6.x86_64 #1 SMP Tue Nov 6 23:43:09 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
Please check if the usb-serial converter is based on a ftdi chip?
(You can check driver filenames)
If so; you have a chance to change serial number,or even the manufacturer info.
http://www.ftdichip.com/Support/Utilities.htm
Check the tools; MProg and FT_PROG utility tools.
Related
Getting status of serial ports (ttyS*) via linux terminal is simple:
sudo cat /proc/tty/driver/serial
Then it shows serinfo with list of all uarts with info about status and buffers. When I call
sudo cat /proc/tty/drivers
then I can see that rfcomm drivers are available:
rfcomm /dev/rfcomm 216 0-255 serial
And, of course, reading data comming from paired bluetooth device is not a problem.
The question is: how to get status of rfcomm serial ports (e.g. Blueotooth SPP devices)? Is this information available somewhere in the /proc directory like for ttyS* or could I use totally different way?
It depends what status you are looking for. The "rfcomm" command that comes with bluez does have some status info. It depends if that is adequate for you.
% rfcomm -h
RFCOMM configuration utility ver 4.101
Usage:
rfcomm [options] <command> <dev>
Options:
-i [hciX|bdaddr] Local HCI device or BD Address
-h, --help Display help
-r, --raw Switch TTY into raw mode
-A, --auth Enable authentication
-E, --encrypt Enable encryption
-S, --secure Secure connection
-M, --master Become the master of a piconet
-f, --config [file] Specify alternate config file
-a Show all devices (default)
Commands:
bind <dev> <bdaddr> [channel] Bind device
release <dev> Release device
show <dev> Show device
connect <dev> <bdaddr> [channel] Connect device
listen <dev> [channel [cmd]] Listen
watch <dev> [channel [cmd]] Watch
I have a 1 x USB to 8 x serial ports hub. I have connected 8 devices to the hub (ttyUSB0...7). I need a way to identify which device is at each ttyUSBx port.
I have tried the following command:
udevadm info -a -n /dev/ttyUSB1 | grep '{serial}' | head -n1
and looked at the log in:
/var/log/messages
as advised here:
http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices/
But what I get is the serial number and VendorID:ProductID of the USBtoSerial hub for all the ttyUSBx ports.
Any ideas?
Thanks in advance
Use as this>>
sudo lshw |grep serial
You can find all details about device by type only sudo lshw
My mother tongue is not English, sorry for my English.
I use pppd with a GPRS module.
I use like pppd record record.pcap call tdscdma command to access Internet.And pppdump record.pcap or wireshark to show the record.pcap.
when pppd run ,the record.pcap will save all data and the file size getting bigger and bigger.
Now I am just want save last(Newest) 1Mb(for example,or quantity) message.And how can I limit the file size.
I am more concerned about the recent network conditions. FIFO is not necessary.if the file bigger than 1Mb, truncate it to zero is OK too.
[root#AT91SAM9-RT9x5 logs]# pppd -v
pppd: unrecognized option '-v'
pppd version 2.4.5
[root#AT91SAM9-RT9x5 logs]# uname -a
Linux AT91SAM9-RT9x5 2.6.39 #34 Wed Jun 4 16:12:41 CST 2014 armv5tejl GNU/Linux
Use wireshark looks like this:
Can you use tcpdump program for capturing traffic of ppp0 interface?
There are -C and -W options for limiting size of output files.
Example:
tcpdump -i ppp0 -C 1 -W 2 -w file.pcap
See more from man page: tcpdump(8).
Within a bash script, I use the following:
$ stty -F /dev/ttyUSB0 921600 raw
$ echo -n "some test data" >/dev/ttyUSB0
and it works as expected.
Using a PL2303 USB to RS232 adapter:
$ lsusb
...
Bus 006 Device 010: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 006 Device 011: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Now I tried to do the same with 1 MBd, but got an error:
$ stty -F /dev/ttyUSB0 1000000 raw
stty: /dev/ttyUSB0: unable to perform all requested operations
Also the same message when I try with 500 kBd. Trying 250 kBd the error message is different:
$ stty -F /dev/ttyUSB0 250000 raw
stty: invalid argument `250000'
Try `stty --help' for more information.
As seen here, it's a problem in the PL2303 linux driver.
I'm working on Kubuntu 12.04, 32 Bit. Unfortunally, I don't know how to fix that driver on my system (getting driver source, patch em, compile, install … hmm, maybe I learn a bit and give it a try - advice is welcome).
But maybe there is an updated driver avaliable which is easy to install?
Or does someone know an alternate USB to RS232 adapter which works at 1 MBd (hardware flowcontrol via rts/cts is needed, which works pretty well with the PL2303)?
After the realization that »Prolific and FTDI are competitors«, I bought Ftdi US232R-10 which is a FT232R based device and specified for 1 MBd transfer rate.
With this adapter I'd successfully tested communication at 1 MBd by transfering some GiB data without any error (including usage of Rts/Cts hardware flow control).
Configuring this device using stty like:
$ stty -F /dev/ttyUSB0 1000000 raw
works successfully.
I'm using CentOS 6 and I have two serial ports (two USB interfaces on two different ports), USB1 and USB2. When I connect the USB1, the OS sets her patch to "/dev/ttyACM0", and when I connect the USB2, "/dev/ttyACM1".
But when I connect first the USB2, the OS sets her patch to "/dev/ttyACM0" and no to "/dev/ttyACM1". I need that the USB1 patch be "/dev/ttyACM0" and USB2 "/dev/ttyACM1", regardless of the order that I connect the interfaces. How I do to do it?
Thank you
Create a udev rule that defines the symlink based on the attributes of the USB device (such as the serial number).
Find out information about your device-
udevadm info -n /dev/ttyACM0 -a
udevadm info -n /dev/ttyACM1 -a
Then go into /etc/udev/rules.d/ and create a udev rule. Something similar to the blurb below. Here is a good reference. For lots of examples and more discussion, do searches for udev persistent usb serial.
SUBSYSTEM=="tty", ATTRS{idVendor}=="0000", ATTRS{idProduct}=="0000", ATTRS{serial}=="000001", SYMLINK+="ACM0"
SUBSYSTEM=="tty", ATTRS{idVendor}=="0000", ATTRS{idProduct}=="0000", ATTRS{serial}=="000002", SYMLINK+="ACM1"