Hi,

So far I've successfully run the hello world example that makes the LED blink. I'm trying to run example code for the USB APIs, like what is shown here:

https://os.mbed.com/docs/mbed-os/v5.12/apis/usbkeyboard.html#usbkeyboard-example

It compiles, and appear to load without any errors (no fail.txt). However, when I plug in the target MCU USB port (J5) (not the debug USB port), I never see a device show up. I'm using debian 9 and running lsusb to check for USB connections.

I assume I should see "Hello World" printed into a text window, as if I typed that on the keyboard, but I don't get that either.

Any ideas what I'm doing wrong?

Hi Kevin,

Do your board have built-in USBPhy? You might have to provide a second constructor, which takes a USBPhy as one of its parameters. You can use this to pass an off-chip USBPhy into any of the USB clases. This constructor does not connect or block, so you must do this elsewhere. Something like:

1. include "usb_phy_api.h"

1. include "mbed.h"
2. include "USBKeyboard.h" USBPhy *phy = get_usb_phy(); USBKeyboard key(phy);

int main(void) { Start the USB connect sequence key.connect();

Block until ready key.wait_ready(); while (1) { key.printf("Hello World\r\n"); wait(1); } }

Regards, Pekka

Hi Pekka,

Thanks for your reply. I have not had a chance to try yet, but I think it should work now that the newer OS versions are supported for this board.

I also replied here: https://os.mbed.com/forum/helloworld/topic/35684/

Best, Kevin