I have a raspbian with an USB connection to an arduino (/dev/ttyUSB0).
I would like, each times I replug (after unplug it), to run command, but I have no idea how to do this.
Reset the speed configuration and restart the program that use it.
Does someone known what to do ?
Ports are in any Linux represented as files. So you can make script in any language which in loop will be checking if the file with specific name exists (The name of port you looking for). If the file is detected than you can execute what you want.
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I'm writing an app that allows an Arduino plugged in via USB to send serial data to the app to graph it in realtime. It can scan available ports for the Arduino and attempt to connect to it, but I'm running into permissions issues whether I use pyserial or QtSerialPort. I have added my user to the groups tty, uucp, and dialout. (When listing ports I see that they belong to uucp.) This doesn't seem to do anything. I can chmod a+rw the port every time the Arduino is plugged in but this is not practical because less technical users (i.e. my kids) need to be able to plug it in and use it via a GUI that I'm writing. I've seen suggestions to run the whole script with sudo but this seems less safe than it needs to be, and also requires typing in the command line.
Is there a way to read from the serial port without resetting permissions every time I plug the USB cable in? Or if not, is there an accepted way to do this from the GUI to make sure the permissions are right before the attempt to connect, without running the whole program as sudo? I'm building this on Linux (Arch) btw.
I solved this using udev rules. I created the rules file, which I called /etc/udev/rules.d/80-arduino.rules, and inside I put the following:
SUBSYSTEMS=="usb", ACTION=="add", DRIVERS=="usb", ATTRS{idProduct}=="0042", ATTRS{idVendor}=="2341", ATTRS{manufacturer}=="Arduino (www.arduino.cc)", ATTRS{serial}=="85734323231351404021", RUN+="/bin/arduino_added.sh", RUN+="/bin/device_added.sh", MODE="0660"
This selects for my specific device by serial number as well as manufacturer (ATTRS{serial}=="85734323231351404021"), runs a little script that writes something to a logfile it creates in /tmp (for debugging), and the MODE="0660" opens the port with permissions to let it be accessed.
I had to mess with it a bit to get it to work. Running sudo udevadm control --reload was enough to get the script to write to the logfile each time it was plugged in, but I had to reboot the computer to get it to work with the permissions for some reason.
On my raspberry pi running raspbian (unix based i think) I get this error "job pending on /dev/sda1" every time that i plug in my USB flash drive. from my research it has something to do with mounting and un-mounting the device but I'm new to command line and most other posts are over my head. What do i do to fix this error?
if it matters i'm running a script on the pi that writes to that flash drive
Your desktop (LXDE for Raspberry Pi) has spotted that you have inserted a USB disc and has tried to mount it. You can enable or disable this behavior by editing the file ~/.config/pcmanfm/LXDE-pi/pcmanfm.conf and changing the line
mount_removable=1
to set '0' instead.
You would get that error if there were more than one thing trying to mount your USB disc at the same time. The second to run will notice that the first has already started a job to mount the disc.
Are you running two copies of your desktop GUI? (You may not realize that you are, but if you have a VNC or XRDP service you probably will be.)
If that is the cause of your problem (and probably in any event) the message is harmless. Something will have mounted your USB disc (perhaps you can even see it in /media?) The only infelicity will be that your desktop won't show you the results (e.g. by displaying the drive in a file manager.)
Is that possible to achieve Inter process communication using any terminal or serial ports in AIX or Unix?
I would like to achieve this by using commands/scripting only where one process writes a string on terminal and another process reads same terminal and processes that string. I know that using pipe also this is possible but I do not have enough idea on that.
Also is there a way we can determine which all ports/terminals are available in AIX machine?
Or is it possible to create new terminal at run time (not the boot time) that will be used by only above two processes?
I think what you want are pty's? Or, another option would be unix domain sockets.
The answer to your first question is "no"... not really. When you write out to a tty, that output is sent out to the real device and not available to be read back.
The list of tty's on a system is: lsdev -Cctty
Creating tty's at run time is possible but not really what you want either. A tty is a child of a serial port and you can not add serial ports arbitrarily. They are real things. With AIX and Power systems, you can add devices while the system is up (hot swap) but that is getting (I'm assuming) way far off your original topic.
The basic different between a pty and a unix domain socket is a pty mimics the output and input process of a real tty in one direction. This is what telnet, rlogin, ssh, and many other daemons use when connections come in. It is easy to make ksh believe that it has a real tty by using pty's. If you don't need that, then they are added trouble that you don't need. Find a link on how to create and use a Unix domain socket and you will have what you need (or a pipe but a pipe requires a parent / child relationship which I assume you do not have).
We are trying to transfer file using minicom (in host pc) and picocom(in arm based evaluation board) combination.
On evaluation board side we have /dev/ttygserial and on host pc side we have /dev/ttyUSB0.
Host side minicom setup is as follows,
Serial device - /dev/ttyUSB0
Baud Rate - 115200
Steps to set minicom in receiving mode.
press ctrl+a R , select zmodem.
Now minicom will start waiting for file from other end.
On evaluation board side we use picocom as follows to send the file.
On command line execute picocom -b 115200 -s "sz -vv" /dev/ttygserial
Now press Ctrl+A and Ctrl+S.
Picocom will ask for filename by printing **file
Once file name is provided and enter is pressed file is sent to host.
All this steps works and we are able to transfer different types of files from evaluation board to pc but now we want to put this procedure into C code. For that I have following doubts,
Is it possible to set minicom in file reception mode using single command? (meaning noninteractively) ?
Is it possible to send file using picocom in single command (meaning noninteractively)?
Any other suggestions?
In other sites also people have asked this kind of question but questions unanswered yet.
So I decided to look into picocom code and found that it is very simple to make a change in that code.
I have made send command non-interactive, I will make receive command too non-interactive and post full code here so that it can be referred by anyone who has a similar problem.
When I use Minicom to capture data from a serial port, I need to save the big data into a file, named minicom.cap. However, if I press Ctrl+A and L to capture file, it failed. No file was created (minicom.cap did not exist beforehand). My download directory was properly created. My OS is Mint, and I read data from Arduino nano v3.0
Did you try to start minicom as
minicom -C capturefile
Unless i got something wrong, it should start to capture incoming data immediately.
OP might miss step "Shift + L" after writing, so the overall procedure is as below:
1 (inside minicom)
2 Ctrl A + Z
3 Shift + L
4 (wait for writing ... )
5 Shift + L
6 (check the file you have written, default is minicom.cap, you may want to find it at /root/minicom.cap)
chown root:dialout /etc/minicom/minirc.dfl
chmod 664 /etc/minicom/minirc.dfl
Now any member of the dialout group can write to minirc.dfl
minicom needs a configuration file that is under root permissions and is stored at /etc/minicom/ and is named minirc.dfl.
Usually when you first run minicom for the first time, as sudo, you can save the minirc.dfl, as if you run as any other user it will not save.
That may be your problem.
This is a little more than the scope of the question calls for but as it has already been answered, I thought somebody might like to do things a little user friendly.
You might be interested in this if you frequently open up a serial connection to multiple devices. You can do this with desktop shortcuts.
I use this for switch and router connections, I have two different console cables, a USB to mini USB and also a db9 with USB A adapter to rj45.
Using the shortcuts here means I don't need to manually reconfigure minicom every time I want to switch devices. The shortcuts give the correct configuration file as a parameter (identifier) as well as the capture file (-C). All i need to do it make sure my devices are connected to my computer with the cables.
If this is something you could use, run these commands as a normal user from your terminal (not from minicom). The configuration files will be saved to your home directory where minicom can find them.
Make a log file directory: You might choose to just log in /var/log but I want quick access to the log files.
mkdir ~/minicom
Find your device:
dmesg | grep tty
If your cable uses an RS-232 chip such as some usb to mini usb console cables, your tty device will likely be on ttyACM* and not ttyUSB*
Create the minicom configuration file using nano. Adapt the capitalised parts to fit your needs, baudrate may be set incorrectly if you get quirky characters or no output. You may create as many as you need along with the desktop shortcuts. just change the identifier.
nano ~/.minirc.IDENTIFIER
pu port /dev/ttyDEVICE
pu baudrate 9600
pu rtscts No
pu logfname /home/USER/minicom/IDENTIFIER.log
Create a desktop shortcut.
nano ~/Desktop/IDENTIFIER.desktop
[Desktop Entry]
Encoding=UTF-8
Name=Minicom IDENTIFIER
Comment=Something relevant to your connection/device name maybe
Exec=minicom IDENTIFIER -C/home/USER/minicom/IDENTIFIER.log
Terminal=1
Type=Application
Make it executable
chmod +x ~/Desktop/IDENTIFIER.desktop
That's it now test the connection, double click your new shortcut.
A note about the IDENTIFIER part, it can be anything. a router or switch model, a device name or type. Do what suits you but maybe use hyphens instead of spaces, I've not tested that but i would imagine they would cause issues such as only getting the name before the first space or worse, attempting to load multiple minicom.identifier files.
Once you have created your first connection, open another terminal:
tail -fn25 ~/minicom/IDENTIFIER.log
Because you have set minicom to capture output, by tailing the log/capture file you can scroll back as far as you need should you be running things with lengthy output, It can be useful for configuration files in routers/switches for example which can be thousands of lines long. Just scroll to the part you are working on in the tailed file to use as a reference while you make changes in minicom, the tail terminal will still collect data but will not automatically jump back to the new line as minicom does when you star to type.
If somebody more shell savvy than myself would like to add to this to make a shell script that accepts the required parameters for setting up a new connection profile,logs etc I wouldn't be too upset about it :)
As an aside, I wanted to add a command prior to minicom running in the shortcut to apply a title to the terminal window using the identifier, I could not get this to work in Ubuntu 20.04 at the time of this posting.