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[Zedboard] usb-uart only works on PC

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Adventurer
Posts: 67
Registered: ‎04-18-2017

[Zedboard] usb-uart only works on PC

Hello,

 

I have a simple project where depending on the pushed button, I send different strings on the UART. This works great if I connect the USB-Uart to a computer and via the terminal connection on SDK I can see that the messages correspond to the pushed button.

 

I have a Parallax's Eddie robot with it's control board, which includes a UART to USB converter, according to the documentation it "enumerates as a serial COM port". Therefore, I thought if I can see the messages on the SDK terminal correctly, I could switch the cable from the PC to the robot and I would be able to duplicate what I do when I connect the robot to the PC and use a terminal software (i.e.: putty) to control the robot.

 

As soon as I connect the usb from the robot, I can see that the LEDs on the Zedboard connected to Tx and Rx do not turn on. Therefore, there is even no data coming out from the Zedboard. The same happens if I do not connect anything to the USB-UART connector on the Zedboard. The opposite happens when I connect the USB cable to the PC. Then, I can see the Tx LED light up as soon as I push a button.

 

According to the documentation, the Zedboard includes a UART to USB as well (image from the Zedboard's user guide):

 

zedboard.jpg

So, I should be able to directly connect the robot's usb cable (as it enumerates as a COM) to the Zedboard and be able to send back and forth data via the UART. Am I missing something?

 

Thank you very much for the help.

zedboard.jpg
Adventurer
Posts: 67
Registered: ‎04-18-2017

Re: [Zedboard] usb-uart only works on PC

BTW, I have a standalone application for this. Could it be something related to the Cypress that were installed on the PC?
Moderator
Posts: 112
Registered: ‎04-12-2017

Re: [Zedboard] usb-uart only works on PC

Hello @aripod,

 

In first place it looks like a driver issue.

The On board Tx Rx LEDs will light up only when there is a proper hardware communication is happening between the system and the board.

So obviously in your case robot cannot provide the USB-UART drivers for communication.

 

 

hope this answers your query.

Thank you.

 

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Adventurer
Posts: 67
Registered: ‎04-18-2017

Re: [Zedboard] usb-uart only works on PC

So rather than a standalone application, I should build a linux application, have linux running on the zedboard so I can install the drivers then?

 

Would it be possible to just install them or I would have to download the source files and compile them myself?

Moderator
Posts: 112
Registered: ‎04-12-2017

Re: [Zedboard] usb-uart only works on PC

Hello @aripod,

 

 

Yes, You are Right.

 

You will need a standalone application on board to communicate with the peripherals.

You can start with the example designs from below link:

http://zedboard.org/support/design/1521/11

 

Thank you.

 

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Adventurer
Posts: 67
Registered: ‎04-18-2017

Re: [Zedboard] usb-uart only works on PC

I am already communicating with the peripherals. I am able to send data over the UART to a PC, where the drivers are installed. The thing that seems to be the issue here is that I should also have the drivers for the tf232rl that is in the robot (which is installed on the PC and that's why I can communicate with it).

 

This is why I thought that I should have a Linux application and running on the Zedboard, to include the drivers first for the tf232rl and then I could communicate to the robot over the USB-UART from the Zedboard. Is that correct?

 

Thanks for the help.