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8051 serial communication. USB cant recognize

So, i am using a development board with a C8051F388. 

the problem is, i was trying to use the serial port via USB to connect to PC, and use a terminal to see what it was outputting, but when i try to choose the COM port, it does not show that i connected 

Every time i plug it to PC it shows a windows message

 

and when i go to the Device Manager it show that the device was not recognized 

 it is in PT. is says "Unknown USB device" and in Properties shows a error called (code 43)

the board uses a FT230XS-R FTDI driver. I already installed all drivers but still cant solve the problem.

p.s. at moment the board is only using the USB plug to use the serial port. the power and flashing is handled by a USB Debug adapter. 

Ty

  • you may have better luck here since your problem is not Keil related https://www.silabs.com/community

  • a development board

    What development board, exactly?

    Have you checked the board documentation for installation instructions, setup details, fault-finding, etc?

    trying to use the serial port via USB to connect to PC

    Is that USB implemented in the microcontroller, or a USB-to-Serial converter connected to the microcontroller's UART ?

    As says, probably nothing to do with Keil - so SiLabs are probably the best people to ask.

    Or the board manufacturer, it is's not an SiLabs board ...

  • Are you using Windows 7 or Windows 8? Although Windows 7 has VCOM drivers, it needs to be told to use them for a specific VID/PID combination. This means writing a custom driver INF file and using that to let Windows "map" the VCOM driver to your device. Windows 10 can figure it out by itself it seems.

    If this is the issue, Silicon Labs VCOM driver (here) that might solve your problem. 

    The other way that Windows can be unhappy is if there are problems with the USB driver on the MCU side. For example, if Windows doesn't get a valid descriptor from the MCU then it won't be able to configure the driver properly. I've had that problem, too.

  • Windows 7 has VCOM drivers, it needs to be told to use them for a specific VID/PID combination. This means writing a custom driver INF file

    Are you sure?

    I have never had to do that for any Dev Board yet

  • In my case, software using a COM port (USB VCOM) to communicate with our custom prototype worked on Windows 10 (auto-install/mapping of drivers when the prototype was first connected to the PC), but not for lab PCs running Windows 7. So, direct experience with the use of a custom INF file. There might be another solution that works more automagically, but I'm not aware of it. The OP says "development board," but it's not clear if that's a Silicon Labs board, or a custom board built around the C8051.

    For a software example, the NXP LPC54S018M SDK has a sample USB VCOM project that includes a suitable driver INF skeleton and a nice README that explains the steps to modify the file for your specific VID/PID. 

  • OP says "development board," but it's not clear if that's a Silicon Labs board, or a custom board built around

    Indeed.

  • Tanks to everyone,

    i already did what you recommended but it did not worked, so i will try to ask on silicon lab forum as you suggested

    Ty once again for your time