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STM32F4 USB_OTG_HS CDC (Virtual COM Port) Issue

sumit kale
Associate III
Posted on April 19, 2017 at 16:38

Hello,

I am trying to implement USB Connection using High Speed (HS) mode for Virtual COM Port. Under USB_OTG_HS in cube MX i have configured 'Internal FS Phy -> Device_only' &  under USB_DEVICE 'Class for HS IP-> Communication Device Only'.

Initially i did same for Full Speed bus & its successfully running. However when i am configuring High Speed bus i am not getting data over PC.

So what will be possible error?

I have connected USB from Board to PC & Drivers are also installed properly. Clock configuration is also fine (Used Cube MX for same).

By refering some earlier questions from STM Community i tried to do some changes in 'usbd_cdc_if.c' file as well. Do i Need to connect 'PB14, PB15 morpho Pins' to somewhere? Now i have just plugged in my USB through 'CN5' on STM32F4 Discovery board.

I have attached my Code below.

So where i am going wrong?

#stm32f4-discovery #usb_otg_hs
4 REPLIES 4
valentin
Senior
Posted on April 20, 2017 at 02:59

don't you need an external phy for usb hi speed? Maybe check your data signals on d+ & d- whether there's actually something happening.

Posted on April 20, 2017 at 08:49

Hello,

I have configured it in Internal Phy only where i will get Speed of 12 Mbps which is sufficient for my application. Do i Need to connect external phy also if i want to use 12 Mbps Speed (As per Manual i think No)?? I had checked my d+ & d- Signals on PB14 & PB15 resp. But i am getting some wiered Output.

I have attached my clock configuration & pinout.0690X00000606p4QAA.png

Posted on April 21, 2017 at 06:58

No you only need texternal phy for usb 2.0 speeds, AFAIK!

Posted on April 27, 2017 at 16:07

OK. I will give a try..

Meanwhile when i am using STM32F205 for USB Full Speed its giving me 'USB Not recognisable' Error. It worked well over Discovery board.