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USB Communication Problems between ESP32 and EPC 1502

ElvisElvis
in PLCnext Technology & PLCnext Controls

Greetings,


I am working on a project where a motor controller based on ESP32 needs to communicate with an EPC 1502 via the USB interface, using the serial port.


When I connect the ESP32 I notice that I don't get a ttyUSB device as it is supposed to appear, investigating I verified that for the communication I need the CP210x driver which is not installed in the EPC and usbserial which is installed in the EPC.


The Cp210X driver comes on the official website as a source code, a .c, which would need to be compiled, but unfortunately the EPC does not have a compilation tool itshelf.


I also tried to use an already copied version of the driver (CP210.ko) of the same architecture as the EPC (x86_64) but it didn't work because the kernel version is not the same.


Finally I thought about trying to cross-compile the .c file.

However I'm stuck on this part. I don't quite know how to do it.


Would this work or is there a better alternative?


Regards and many thanks in advance.

Comments

  • Martin [PLCnext Technology Team]Martin [PLCnext Technology Team]

    This page shows how to use an SDK for a PLCnext Control device to cross-compile a simple C++ executable:

    https://www.plcnext-runtime.com/ch01-05-hello-again-world.html

    In your case you'll need to include the relevant compiler options if you need to build a library rather than an executable, but otherwise the process should be roughly similar.

    I hope this helps.

  • ElvisElvis

    Hello again,


    Following the instructions on the shared page https://www.plcnext-runtime.com/ch01-05-hello-again-world.html, I have performed the cross-compilation process for a C++ executable. However, during this process, I noticed that some essential libraries are missing, among them "tty_flip.h" or "moduleparam.h".


    Is there any way to customise the SDK to incorporate these specific libraries during cross-compilation?


    Thanks

  • Martin [PLCnext Technology Team]Martin [PLCnext Technology Team]

    Is there any way to customise the SDK to incorporate these specific libraries during cross-compilation?

    It sounds like there are missing dependencies, which means you also need to cross-compile those dependencies. Unfortunately it may be a long and complicated iterative process to build all the dependencies.

  • ElvisElvis

    Is there any other way I can use this driver?

  • Oliver PLCnext TeamOliver PLCnext Team

    Hello Elvis,

    you would probably need the Kernel Sources of the EPC 1522 to proceed here or try a module thats been build for the same kernel version. Check your current kernel version via "uname -a".

    !!! Watch out! We can not guarante correct exectution of device services as soon as you modify your Kernel !!!


    How to build on your development Machine:

    source the toolchain environment.

    make EPC_1522_defconfig //load EPC 1522 Defconfig

    make menuconfig //Activate your driver in the kernel make menu

    make bzImage // If driver ist not purely modular Image needs to be replaced as well.


    make modules // to build the *.ko files

    Then copy the file to your device to /lib/modules/kernelversion/kernel/drivers

    On EPC:

    modprobe <YourDriver>.ko


    Access to kernel soruces etc. can be requested through your local subsidiary.

    Alternativly you could request the integration of the specific driver for the next Firmware Version.


    Kind Regards,

    Oliver

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