AnsweredAssumed Answered

USB CDC Device Failed to Enumerate on USB Host

Question asked by Hui Shao on Oct 4, 2014
Latest reply on Oct 9, 2014 by Hui Shao

Hi-

 

Has anyone managed connecting a USB CDC device to a USB host successfully? My device/host custom boards are like

 

USB CDC device (virtual com), receiving power from host

k20d50m

MQX 4.1.1

 

USB host

k20d72m

MQX 4.0

 

Windows is able to enumerate the CDC device as a COM port and talk to it through terminal when a type 'A' plug is inserted into PC.

 

However, for the connection between two custom boards, I need a regular 'A' to mini 'A' cable with its ID pin tied to ground. What I noticed is that host seems to enumerate the device successfully and starts to send data to device while the device doesn't think the enumeration is done successfully as the callback function USB_App_Callback() never gets called.

 

Any comments or insights are welcomed.

 

Thanks!

 

Hui

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