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Unable to run USB UART Example code in PSOC 5 Kit | Cypress Semiconductor

Unable to run USB UART Example code in PSOC 5 Kit

Summary: 6 Replies, Latest post by odissey1 on 05 Dec 2015 09:18 PM PST
Verified Answers: 1
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ravinder.singh_1492046's picture
5 posts


I am trying to Run USB UART example code on CY8CKIT-059 Kit.

It is not working. i am always getting "USB Device not recognized" message.

Please suggest.


Ravinder Singh

user_1377889's picture
9245 posts

I do not know which example you refer to. Can you post your complete project, so that we all can have a look at all of your settings? To do so, use
Creator->File->Create Workspace Bundle (minimal)
and attach the resulting file.




ravinder.singh_1492046's picture
5 posts

Hi Bob, 

       please find the file attached here.




user_78878863's picture
2551 posts

typical error: the voltage setting in the design-wide resources do not match the ones given to the USB-component (in the startup-code), or the ones that the board is configured for. Check that all three are the same.

WillFlanery_01's picture
10 posts

I am also having this problem.

I have one unmodified CY8CKIT-059 where the USB_UART example works fine.  Obviously, this board is running on 5V and the startup code specifies 5V operation: "USBUART_1_Start(0u, USBUART_1_5V_OPERATION);"

I have modified another CY8CKIT-059 board where I removed R20 and added a 3.0V regulator between VTARG and P5LP_VDD. 
1)  I confirmed with oscilloscope that VDD and VDDIO are 3.0V.
2)  In the project's .cydwr file, under the System tab, in the Operating Conditions section, I changed all VDD settings to "3.0"
3)  In the startup code I have changed the USB_Start argument to 3V operation: 
         "USBUART_1_Start(0u, USBUART_1_3V_OPERATION);"

USB connection fails.  In device manager I only see "Unknown Device".

What else should I try?


WillFlanery_01's picture
10 posts

I found my answer in the PSoC5 Architecture TRM.  The USB peripheral works at 5.0V or 3.3V, not 3.0V.  I changed my regulator to 3.3V and now the USB connection works.

From PSoC5LP Architecture TRM_001-78423_0C:

24.3.2 Operating Voltage
The USB block can operate in two voltage ranges:
■ Standard voltage range – 4.35 V to 5.25 V
■ Low voltage range – 3.15 V to 3.45 V

user_342122993's picture
527 posts

In my case I found that using settings


while operating FreeSoc at 3V works OK, but changing it to "correct" settings


does not. So I just always use "5V" settings.

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