I have software for communicating with a serial device that only runs on Windows 7. My host machine is running Ubuntu 16.04, with Windows 7 in virtual box.
I've managed to set it up using USB device filters in VirtualBox settings so that Windows sees and can communicate with the device.
However I'd like to capture what's being sent to and from the device. I thought something as simple as cat /dev/ttyUSB0 would work but unfortunately when I start VirtualBox I get this in dmesg:
[31199.465270] vboxdrv: ffffffffc0df4020 VMMR0.r0
[31199.653494] vboxdrv: ffffffffc0ef7020 VBoxDDR0.r0
[31199.710573] VBoxNetFlt: attached to 'wlp1s0' / 98:54:1b:04:13:48
[31199.863579] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[31199.863674] ftdi_sio 1-3:1.0: device disconnected
So I don't know which file to monitor in /dev anymore. I suppose I might be able to try listen for the communication from Windows, but if I can I'd like to know if it's possible to monitor it from my host machine.
Edit:
This answer helped me for a start. I now get some cool looking stream on the terminal, next step is deciphering it, or if anyone has a better way I'm interested - it looks like the person who answered that question still has deciphering it as a TODO :-)
The fact that it was communicating with software in VirtualBox didn't really matter. This answer got me most of the way just by (as root):
modprobe usbmon
cat /sys/kernel/debug/usb/devices|less and search for device
cat /sys/kernel/debug/usb/usbmon/7u where 7 is the number from "Bus=" in the device table from step 2
From there is was just filtering the output.
A basic way could be just
cat /sys/kernel/debug/usb/usbmon/1u |cut -d\ -f9- | grep ^\n
But the device I was working with was constantly sending lines with just 4 characters, to filter out those I got the address word from the output line, and grepped for that. In my case I only wanted to capture "C" or callback output. I was also filtering for lines that contained more than just the default "0160" that the device was constantly outputting. To try understand the hex output I put a xxd -r -p at the end which gave me:
cat /sys/kernel/debug/usb/usbmon/1u | grep -e 'C Bi:1:005:1\s0\s\w*\s=\s0160\w' | cut -d\ -f8- | xxd -r
Where the grep is
grep -e 'C <address> <someotherstuff> = <always-output-string><anycharacter>
This still gave me this indecipherable junk below, but I don't know the format so I'm stuck here. Maybe the steps to read and filter will be useful for someone
>
O�UDQN��RG_JAMS142E DEFAULT0XXXXXXX�lSTz:�RSDU�vy��������������������������z�fff=�����{6zC"z�u6zC�z�H
;�����C��Af[���RSC�b ISD�EGIN
�CG_IEW0321:0407JUN12S��Z-�$''$'''C'''
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I have a Raspberry Pi 4 with speakers connected to the 3.5mm jack. I have no HDMI connected, but I have the standard 7 inch monitor connected. It runs raspbian.
Edit: I found out that this was normal behaviour due to an OS update, se my comment below.
If I run amixer cset numid=3 1 I get the error amixer: Cannot find the given element from control default.
If I run amixer contents there are no numid=3, I only get:
numid=2,iface=MIXER,name='Headphone Playback Switch'
; type=BOOLEAN,access=rw------,values=1
: values=on
numid=1,iface=MIXER,name='Headphone Playback Volume'
; type=INTEGER,access=rw---R--,values=1,min=-10239,max=400,step=0
: values=0
| dBscale-min=-102.39dB,step=0.01dB,mute=1
So PCM playback route with numid=3 is missing, and 1+2 say Headphone instead of PCM, that is the normal as far as I can tell from the interweb.
I can still play things with aplay and omxplayer (I'm not sure if it is mono or stereo).
But some other things fails, which I thought might be because of this. If I run espeak, and similar with pyttsx3 in python, I get screens full of errors, a few of the lines are:
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.front
Cannot connect to server socket err = No such file or directory
jack server is not running or cannot be started
And that is what I actually would want to get to work.
If that is caused by the first error I don't know. But when I search for rPi sound problems, the cset-numid=3 "solution" seems to appear everywhere, and I can't use that...
Edit: So that turns out not to be the reason, the espeak problem is still there even if I revert to the old way with options in boot.txt.
I needed three days to find out how to use it on Raspberry Pi. I created an Shell Command. When you want to use Audio via 3.5mm Jack just write. You can let the HDMI Cable connected.
sudo bash -c 'echo -e " defaults.pcm.card 1 \ndefaults.ctl.card 1" > /etc/asound.conf'
if you want to use the HDMI Audio output just change the number 1 to 0.
sudo bash -c 'echo -e " defaults.pcm.card 0 \ndefaults.ctl.card 0" > /etc/asound.conf'
I am start learning Linux(CentOs 5.5 kernel 2.6.35.13).
When I try to install a usb wifi stick(TP-Link TL-WN823N,and "lsusb" will show ID 0bda:8178 Realtek Semiconductor Corp..)
It work fine in the window interface( ctrl+shift+F7).
But when I shift to the command window(ctrl+shift+F1),and try to start wifi connection by
wpa_supplicant -Bw -Dwext -iwlan0 -c/etc/wpa_supplicant.conf
I found it kept print logs to screen before I type the command above.
I use
ps axjf |grep wpa_supplicant
to list all related process and find
there is a process start by user "dbus" with the command
/usr/sbin/wpa_supplicant -c /etc/wpa_supplicant/wpa_supplicant.conf -u -f /var/log/wpa_supplicant.log
I dont know whether is this dbus' command that lead the problem.
Below is the screen shot.
kept logging msg:(
Partly fix the problem.
There are two things that make the wifi information keep on loging on the screen.
First, if you use NetworkManager, it will automate run the command under /etc/sysconfig/wpa_supplicant, where you can find the default command write there has no -B parameter which will keep the log in the background.So you can either add an -B to that command or stop NetworkManager and start wifi connection with your own command like in the question.
Second, when you install the driver, the default run status is power saving mode, so when you transfer data with wifi, you can see the screen keeping log infomation like "get into the pw_saving","get out pw_saving" etc.
To fix this, you can shut down the power saving mode like this:
create a file /etc/modprobe.d/8192cu.conf with the following contents:
options 8192cu rtw_power_mgnt=0 rtw_enusbss=0
Or you can rewrite driver code to stop print the info to screen, which I still don't know how to do.
I am trying to access a device which is attached to a USB-serial port. The settings are 57600 baud, 8 bit, 1 stop bit, no parity. The device outputs a status line every second and accepts typed commands.
I would like to use GNU screen to initiate 2 way communications, so I am using this command:
screen /dev/ttyS2 57600,cs8
However I just get a blank screen, nothing received from the device.
The communication is fine using teraterm, and I can also do this
stty -F /dev/ttyS2 57600 cs8
cat /dev/ttyS2
to see the status output from the device.
I've tried various combinations of ixon, ixoff, crtscts, and clocal but nothing makes any difference.
How can I determine what the correct command should be?
I am using Cygwin on Windows 10.
I faced the same issue with gnu-screen, I started using plink.exe instead from the PuTTY suite. It's not optimal, but it does the job. In my case serial is just for recovery, not for everyday usage.
Start PuTTY, create a profile with your serial connection.
Name and save the connection.
From cygwin, run: '/cygdrive/c/Program\ Files\ (x86)/PuTTY/plink.exe -load SerialProfile'
I am able to scan for all available bluetooth devices with hcitool or with my C program.
I can pair the device using it's address with a simple-agent python script.
I would like to know if I can also remove the paired device using either hcitool, hciconfig or some kind of bluetooth command.
I know the information of detected devices for the hci0 controller is stored in /var/lib/bluetooth/XX:XX:XX:XX:XX:XX, where XX:XX:XX:XX:XX is the address of the hci controller.
This would be useful for testing pairing, connecting and disconnecting devices.
For those using Ubuntu 20.04, here is the same command using the bluetoothctl command
#!/bin/bash
for device in $(bluetoothctl devices | grep -o "[[:xdigit:]:]\{8,17\}"); do
echo "removing bluetooth device: $device | $(bluetoothctl remove $device)"
done
bluez-test-device remove XX:XX:XX:XX:XX:XX
If you install the bluez-tools package, run this to unpair a bluetooth device :
bt-device -r xx:xx:xx:xx:xx:xx
where xx:xx:xx:xx:xx:xx is the address of the paired device.
As it is mentioned above on ashish's answer, you can us bluez-test-device to remove the device which that you already know its mac address. So the problem is to parse the mac address of the added devices.
With python or c or whatever you use,
1) list the devices with;
bluez-test-device list
and parse the output and get all the MAC addresses of the devices, add them to a list.
2) disconnect and remove the devices;
bluez-test-device disconnect <MAC ADDRESS>
bluez-test-device remove <MAC ADDRESS>
Command using bluetoothctl binary: for device in $(bluetoothctl devices | grep -vEi '(o que mais vc quer deixar aqui|samsung|jbl|wireless)' | awk '{print $2}'); do bluetoothctl remove $device; done
All these answers don't answer the headline "removing all Bluetooth devices"
I wrote this little bash script to remove all the Bluetooth devices that are listed in the bt-device -l
#!/bin/bash
for device in $(bt-device -l | grep -o "[[:xdigit:]:]\{11,17\}"); do
echo "removing bluetooth device: $device | $(bt-device -r $device)"
done
How to run?
Make a new file like <fileName>.sh and paste the code above.
Run chmod +x <fileName> to make the script executable
Run ./<fileName>.sh
Celebrate! All Bluetooth devices are removed now :)
I'm printing some labels on a Zebra TLP-2844 printer, and have been doing it fine on Windows by sending the EPL instructions to the shared USB printer as follows:
type Label.prn > \my-pc\zebra
and it seems to work with serial ports too, with
type Label.prn > COM1
Now I'm trying to to the same on Linux, but it's getting really hard! My first guess was:
cat Label.prn | /dev/bus/usb/005/002
since my printer is on bus 005, device 002 (checked it with lsusb command) but it doesn't work at all, as I get the following:
bash: /dev/bus/usb/005/002: Permission denied
Any guesses?
The command you did
cat Label.prn | /dev/bus/usb/005/002
will try to run /dev/bus/usb/005/002, which is not executable, hence "permission denied".
The correct command would be, similar to windows
cat Label.prn > /dev/bus/usb/005/002
However, not sure if you actually can write anything to a printer like that in linux. If the printer is set up properly, you might also try:
lpr Label.prn
In case anyone else is trying to access raw USB printer ports; The "permission denied" problem is circumvented by adding your user to group "lp", like so:
$ sudo usermod -aG lp USERNAME
where USERNAME is your username.
Sorry by My english.
I tested here, my printer TLP2844 connect on USB, in my embedded arm9 board with linux.
I typed in command prompt:
printf "OD\r\nN\r\nD5\r\nS2\r\nZT\r\nQ128, 24\r\nq400\r\nA15,10,0,2,1,1,N,\"TESTE\"\r\nP1\r\nFE\r\n" > /dev/lp0
and... the TEST printed
You should change access mode for /dev/usb/lp0 device: sudo chmod a+w /dev/usb/lp0
And then you can print a label using copy command: cp test.zpl /dev/usb/lp0
Also you can create your own build system in Sublime Text for example:
{
"cmd": ["cp", "$file", "/dev/usb/lp0"],
"encoding": "utf8"
}
and send files to the printer by pressing Ctrl+B keys immediately after finishing edit the label.
Or you can try my tool to send zpl labels to the printer via TCP/IP:
https://github.com/kashamalasha/AutoIt_ZebraTester
It was written on AutoIt Script language, so you need to install AutoIt to build it. Unfortunately there is no description on English, only Russian, but I can write it very soon, if you will need it.