I am using a uC board that continuously streams sensor data. I have managed to get labplot to read the CSV - but apparently only one at a time. It updates the reading as expected on refresh, but I can’t get it to read the number of values I dial in - nor can I successfully exit the streaming pop-up window. The OK button is always greayed out.
Can anyone direct me to a solution?
We had a bug in the check when to enable the Ok-button in the dialog. It was fixed in 2.11 (LabPlot 2.11 released – LabPlot). Can you please try out with the new release?
Hi, I managed to install 2.11 on a fresh disk with Mint 22 using the software manager (none of the online Ubuntu deb installers work).
And now the ok button is no longer greyed out, but the streaming port choices are only a lot of ttys. I can no longer get labplot to read the streaming data whatever setting I pick.
What am I doing wrong?
TTYs are the devices on Linux, you won’t see any COM here since this is Windows’ terminology. Please check GitHub - Chrismettal/LabPlot-Serial-Examples for how to determine which tty is used by your device.
Hi again, sorry to be such a nuisance, but I am new to this program and I’m afraid that LabPlot is not very self explanatory - and the help function does not seem to be quite finished yet. So I am afraid that pestering you with my newbie questions is my only option, it seems.
I followed Chrismettal’s instructions in the link that you provided to a T, but now the ok button is greyed out again and I can’t get any data in.
Actually, so is the option to ‘Update on new data’ which I wold have preferred.
There was a mention about a need to accurately match the update interval to the incoming data rate “but that could be about to change”. Has this changed? And how would I know the exact data rate from a non-synchronized data source?
So the basic question remains: What am I doing wrong?
There must be now an explanation for the reason why the Ok-button is greyed out. Do you get it if you hover of the Ok-button? Something like wrong post selected maybe?
Hi Alexander, I have tried everything, including hovering over and furiously hammering the grey ‘Ok’ button - no luck. (The ‘Cancel’ works nicely).
I also checked the input port using ‘sudo dmesg’ and it definitely said ttyACM0 was connected to my Microchip device.
Further, I tried to see how many data lines the PIC sends per second using TeraTerm, and it appears to be 25-26, indicating one every ~40msec.
Of course I don’t know whether this is TeraTerm’s max update rate, but I will try to dial intervals from 20 to 30 in LabPlot to see what happens.
Bui why can’t I select ‘On new data’?
Thanks,
Per
don’t try to click on the Ok-button, it’s disabled and it won’t work. When we disable the button, we show a text with the reason for this. Can you please just hover over the button and stay for a couple of seconds over it until you get the tooltip text shown? Which text are you getting?
I think I see the bug now in the code 
Can you please select “File or Named Pipe” for the source first and not SerialPort and then select an arbitrary text file? After this you can switch back to Serial Port and try again. Does this work for you?
That selection cleared the ok button, choosing any of the others does not.
The error message when hovering is ‘Could not connect to serial port’.
I double checked with dmesg and the ttyACM0 port is the correct one.
Another observation: if I open this window before I connect the sensor pcb, there is just a list of tty# options.
If I attach the sensor before opening the window, it immediately comes up with ttyACM0 - so the program can apparently ‘see’ the port, but not connect to it?
Hope this helps.
Per
Further, I installed and ran PicoCom on the ttyACM0 port - data is definitely streaming through.
I truly hope that you guys can figure out what the problem is, everything else about LabPlot looks to be exactly what is needed.
I should add that the first time i ran PicoCom just as:
picocom -b 9600 /dev/ttyACM0
the program started, but would not permit the streaming of data.
But when I put in:
sudo picocom -b 9600 /dev/ttyACM0
the program started, paused and then the streaming data poured in.
So could the snag lie somewhere in Linux’ permission system? How would you get around it?
Does the Windows version require “Run as administrator” to work?
Again, sorry for all these newbie questions.
Per
Missing permissions can be an explanations for your problem indeed… Usually the owner of those devices is the root user and the group dilaout. Probably your user is not in this group. Can you add your user to this group with
sudo usermod -a -G dialout $USER
and try again? You might need to relogin again.
P.S.: you don’t need to worry about your questions 
We’ll solve your problem. You’re helping us to improve the application and to better document the relevant workflows. Thank you!
Not much luck, I am afraid. I am the only one using this computer and I am already listed as a superuser (just cf. the top of the picture above).
Even so, I tried to type in sudo -i and then I could run the Picocom straight away.
However. nothing changed in LabPlot - it still says that it can’t connect to the ttyACM0 port. 
If I read the possible error messages on the serial port in https://doc.qt.io/qt-5/qserialport.html#SerialPortError-enum correctly, the device can be opened only once. Are you reading from it with one single application at the same time?
I improved now a bit the error handling in this dialog to show the actual error message coming when trying to read from the device. Would it be possible for you to try out tomorrow our last nightly build?
No, the port does not connect to more than one application at the same time.
I would of course try the Nightly build - if I can install it on the Mint 22.
Any advice?
Hi, any developments on the plot streaming front?
the nightly build package for Ubuntu is not working at the moment, needs to be fixed now after the recent port to Qt6. We’re in contact with the maintainer of this package. Once it’s available soon again, let’s please try it and see which error message you’re getting for your device. I’ll update here soon again.