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USB Device Unkown with USBUART_1_cdc.inf file | Cypress Semiconductor

USB Device Unkown with USBUART_1_cdc.inf file

Summary: 2 Replies, Latest post by ngohara on 19 Oct 2015 10:06 AM PDT
Verified Answers: 1
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ngohara's picture
36 posts


I am working on a project using the USB_UART module, and I am having some difficulties with the device driver.

I have created and used a project for the CY8C58LP module on the CY8CKIT-001 developement kit, and used the USBUART_1_cdc.inf file in it's generated sofware folder. This device driver works, and the PC can connect to the PSoC device just fine.

I've used the same code and USB_UART module for another project (same code, different hardware), this time for the CY8C5666LTI-LP005 chip on a custom PCB. This project compiles and programs to the board just fine.  I should note that I am programing this chip with the 5pin Miniprog connected to a custom 5pin cable on a usb micro connector. 

Using a separate usb micro cable (which is standard 4 wires) I now try to connect my PC to this device, with the appropriate USBUART_1_cdc.inf file,  and I get Device Unknown, even when I try to get the Device manager to specify that custom driver.


Geven that these project are as identical as I can make them, and the USB ports are connected just the same ( D- to P15.7  and D+ to P15.6 for both), and I see appropriate USB signals on my custom pcb, I feel that there might be something wrong with the device driver, given the chip change.

Can anyone recommenced any steps to follow to get this device driver working?


Thank you


PS:  attached is my USBUART_1_cdc.inf file for the CY8C5666LTI  in  .txt format

HIMA's picture
Cypress Employee
169 posts


Can you please follow the below mentioned items.

1)Test The USB HID example project in PSoC Creator. If this is working fine means USB HID port is functioning properly

2)In the USB_UART project make sure that voltage is configured properly.

3)Try to bind the device to windows certified serial driver 


Please refer to : more details.Please let us know if it is working fine after following these steps.



ngohara's picture
36 posts

Ultimately, it appears Windows is finicky about connecting to my hardware. In terms of USB, the device is now detected everytime it is plugged in. However, that are many times where opennening a serial port connection with ruby (which uses WinApi I believe) to the device fails (however, putty serial connection almost always work).


So, something seems really finicky software wise on the PC side, even though the hardware looks fine and connects fine.



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