stm32l053 USB VCP not getting detected

[LRPS_92]

Posted on July 29, 2017 at 11:14

Hi,

                 I'm currently working on stm32l053 VCP. I've done a code to initialize & start VCP driver in stm32l053 and tested it using stm32l053-DISCO board, where it works fine. I can able to detect the com port in my pc(I've downloaded & installed the VCP driver from ST).

When i flash the same .bin file to my custom board i'm unable to detect the VCP in my pc. I've used the same circuit provided in the stm32l053-DISCO Schematic for my custom board. I can see voltage at USB point 4.95 V and MCU is powering on at 3.56V and Vdd USB at 3.46 V. I don't know what i'm missing in my custom board. Could anyone please help me with this issue.

#vcp #stm32l053r8 #usb #stm32l053

[Vangelis Fortounas]

Posted on July 29, 2017 at 11:44

Hello!!

Is your board feeding from usb port itself? or from another external source?

In first case , put some milliseconds(10,20,..) delay before you initialize your usb port.

You wrote 'I've used the same circuit provided in the stm32l053-DISCO Schematic'  You mean only about usb cirquit?

Check if  VDDA, VSSA  VDD_USB, BOOT, NRST  pins  connected as the other board.

[LRPS_92]

Posted on July 29, 2017 at 13:01

Hi Vangelis,

                 Thank you.. It's working now. I didn't connected the USB_DP & USB_DM pins correctly, I swithced it instead.