USB example XMegaA1UXPlainedPro

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I need pointers on how to use the USB of the XMega devices.

 

I am trying the USB CDC example using the XMegaA1UXPlainedPro eval board. I have the laptop connected to the EDebug port of the eval board. I have an USB cable connecting the eval board to the laptop. I am referring to the app note

Atmel AVR4907: ASF - USB Device CDC Application (microchip.com) . I don't have any UART to USB bridge connector, I assume the xMegaA1UXPlainedPro has a virtual COM port that takes care of this?

 

I ran the example and opened two teraterm windows, one for the eDebug COM port and another for the CDC class ASF example COM port. The text I type into the eDebug window echos on the CDC class example. If I type into the CDC class example window, no echoing happens. I need help understanding how to use this example.

 

In the application the MCU used will be Atxmega 32A4U. The attached picture shows the use of the USB port. External interrupts happen on the GPIO. The Atxmega32A4U processes this data into an internal buffer. When the processing is complete, this data from the buffer has to be sent to the SBC via the USB. How can I use this example for what is needed in the application? 

 

Edited to add: I have ordered an STK-600 eval board with the routing card for the AtxMega32A4U. In the meantime, I am using the XMegaA1UXPlainedPro eval board.

 

Thanks.

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Last Edited: Tue. Feb 16, 2021 - 06:31 PM
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I bravely used this example and added udi_cdc_putc('x'); in the main loop. I can see x's in the CDC teraterm window. I will develop the rest of example with this project as a baseline for the USB interface.

 

I can see in the XMegaA1UXplainedPro scehamtics the Edebug USB goes through the UART of the on board emulator chip AT32UC3A4256J-C1UR. This UART is connected to the UART of the  ATxmega128A1U-AU. This helps me understand the EDebug is a virtual COM port.

 

What happens when the target USB of the ATxmega128A1U-AU on the XMega_A1U_XplainedPro is connected to the laptop? What makes me be able to see USB data on the teraterm window? Is this an automatic connection to the RS485 of my laptop? I need to understand this part, so I really appreciate a response.

 

Is it the same process-- target USB to UART of on board emulator chip to laptop? In the real application PCB, I will need a USB analyzer for this? I am going to try the free USB protocol analyzer program to find out what happens. If I am making incorrect assumptions, I hope some one here will reply.

 

Thanks.

Last Edited: Wed. Feb 17, 2021 - 05:48 PM