2 years ago.

Is it possible to use the USB port (not the ST-Link one) using mbed-os on Nucleo F429ZI?


I am using the Nucleo F429ZI board, with mbed-os. I was wondering if I could use the onboard micro USB (CN13) for serial port connection to the F429ZI. It would be nice to use, because it faces the same direction like the onboard Ethernet connector. In my use case the Nucleo F429ZI would be used like a "behind-panel mounted" device with only Ethernet and micro USB sticking out of the metal panel's surface. I plan to use the Ethernet functionality (TCP server), so I used the mbed-os-tcp-server-example as a starting point. This one is based on MBED-OS. I also plan to use an other SPI port, so I honored the precautions of re-mapping D11 according to the wiki page. The ST-Link part of the Nucleo board will not be powered in the end application, the Nucleo will be powered by E5V (extenal 5V). X3 oscillator is populated, SB-s are configured the right way to allow ST-Link-independent operation, including NRST (reset) line. Of course I could use an unused UART port to do something similar (by adding a UART/USB interface), but this would not be my first choice, since the availability of the micro USB socket.

As far as I could determine, USBSerial may not be supported by the current MBED os (let alone mbed-os?). Trying to compile the generic USBSerial example for mbed-os, gives the error:


Error: Cannot open source input file "USBSerial.h": No such file or directory in "global.h", Line: 12, Col: 24

Note: I have a global.h file where I collect all the includes, definitions, function prototypes, etc.

Has anyone ever tried to use that USB port this way when compiling a project created based upon mbed-os?

Any hint is welcome!

Thank you and Best Regards:


1 Answer

2 years ago.

Hi there,

it is only tip not a solution but you can check this ST example based on ST USBHOST library. I used that when I wanted to use USB Stick. In the library exist folder with name "USBHostSerial" (I have no experience with that part), maybe it will help.

Best regards J.

Hi Jan,

Thanks for the tip, I will investigate it!

Best Regards: Balazs

posted by Balazs Bornyasz 26 Aug 2019