USB Uart fails after PC reboot

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jofo_817731
Level 1
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Hi,

I have a problem with the USB Uart. It works fine until you reboot the PC. When the PC starts up again, the PC cannot write to the PSOC, while the PSOC can write to the PC.

When the error happens you can just disconnect the USB cable and connect it again and it works, but this is not an acceptable solution. It is the same on any computer as far as I have seen.

To reproduce the problem, run the attached project. It is an echo terminal (similar to the CE95396 code example​), so test with for example Tera Term. You should see all characters echoed on the screen, then reboot the PC while the USB cable is still connected. Now open Tera Term and connect to the USB UART. You will see it does not work. Disconnect and connect the USB cable and it works again.

Can anyone help?

Thanks!

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AnkitaS_51
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Hi,

Please check this CE as attached.Please make the Jumper connection on J4 on CY8CKIT-059.

I checked the CE attached (available in PSoC Creator 4.2 too) on rebooting the system, there was no issue in receiving the echo.

Please check for elimination of any  hardware issue in your setup.

You can use Microsoft certified USBUART driver file available at this link:

https://www.cypress.com/documentation/software-and-drivers/microsoft-certified-usb-uart-driver

Thanks,

Ankita

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AnkitaS_51
Employee
Employee
100 likes received 50 likes received 25 likes received

Hi,

Please check this CE as attached.Please make the Jumper connection on J4 on CY8CKIT-059.

I checked the CE attached (available in PSoC Creator 4.2 too) on rebooting the system, there was no issue in receiving the echo.

Please check for elimination of any  hardware issue in your setup.

You can use Microsoft certified USBUART driver file available at this link:

https://www.cypress.com/documentation/software-and-drivers/microsoft-certified-usb-uart-driver

Thanks,

Ankita

jofo_817731
Level 1
Level 1

Great, thank you. I had missed the

UsbUart_IsConfigurationChanged() check and UsbUart_CDC_Init() in the main loop, I only did it once when the device started up. It works now.

Maybe a good idea to update the CE95396 example, as I had copied the code from there.

Cheers,

Jostein

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