EK-TM4C123GXL: USB OTG Mouse Example - Hardware and Software Issues

Sheldon Maciel

Part Number: EK-TM4C123GXL

Hello,

I am working on a project to control a robotic arm with a USB Mouse/Keyboard, and my partner and I have been struggling for the past week trying to connect the USB Mouse to connect and power on through the USB Device Port built on the TM4C MCU.

So far, we have R25 and R29 shorted to enable the USB device to receive power and also shorted the two pins above R14 (center and right).

So far, when we plug the USB Mouse into the board, it flashes the red LED on for a split second, then turns off and stays off. But the PWR LED on the board still stays on, so the board is still receiving power from the USB Port.

We used the example from "C:\ti\TivaWare_C_Series-2.1.3.156\usb_otg_mouse" and are trying to make it work with the EK-TM4C123GXL board.

If anyone has any suggestions on how we are wiring it and if there are any examples that work with our particular board, please let us know! Also, if there are any licensing issues since we are using the free software trial, please let us know if this is possible and if we should continue or not.

This is our current system overview:

Thanks in advance!

Sheldon

over 8 years ago

0 Bob Crosby over 8 years ago

TI__Guru 72500 points

What voltage do you measure at R29 with the mouse plugged in?

0 Sheldon Maciel over 8 years ago in reply to Bob Crosby

Intellectual 400 points

Hi Bob,

Thanks for your quick reply! I measure 4.54V at R29 with the mouse plugged in.

Thanks,

Sheldon

0 Bob Crosby over 8 years ago in reply to Sheldon Maciel

TI__Guru 72500 points

Could it be the mouse turning itself off when it does not recognize the host port? (In other words, the software configuring the OTG port as a host.) You might try plugging the mouse into a "power only" USB "host" such as a cell phone charger and see if it behaves similarly.

0 Sheldon Maciel over 8 years ago in reply to Bob Crosby

Intellectual 400 points

Oh yes, that is a good idea. My partner and I tried that already and the LED stayed on even when no data pins were connected.

0 Bob Crosby over 8 years ago in reply to Sheldon Maciel

TI__Guru 72500 points

OK, what is the voltage at R29 without the mouse plugged in?

0 Sheldon Maciel over 8 years ago in reply to Bob Crosby

Intellectual 400 points

I measured both with and without the mouse plugged in for consistency sake because I am using a different power supply.

They both read: 5.09V.

0 Bob Crosby over 8 years ago in reply to Sheldon Maciel

TI__Guru 72500 points

Sorry, I don't know. I will see if I can get someone else to help.

0 Sheldon Maciel over 8 years ago in reply to Bob Crosby

Intellectual 400 points

No problem, thank you so much for taking your time to help us debug some potential issues!
Have a great day!

0 Amit Ashara over 8 years ago in reply to Sheldon Maciel

TI__Guru**** 244400 points

Hello Sheldon

The connections seems fine to me. What is the source project that you are using for the TM4C123x micro on the board?

0 Sheldon Maciel over 8 years ago in reply to Amit Ashara

Intellectual 400 points

Hello Amit,

Thanks for your reply!

What do you mean my source project? Do you mean where did I get the example code? The example code I will have to figure out and let you know where I got it, it was just an included example I believe in the boards folder. I will check and get back to you.

Thanks,

Sheldon

0 Amit Ashara over 8 years ago in reply to Sheldon Maciel

TI__Guru**** 244400 points

Hello Sheldon

Under the ek-tm4c123gxl examples there is no USB Host or USB OTG example. Only present are USB device examples.

0 Sheldon Maciel over 8 years ago in reply to Amit Ashara

Intellectual 400 points

Hello Amit,

I understand what you mean now. I used the below example, the only thing I noticed is that it is trying to compile to a different board as seen in the picture below.

At one point I tried switching the board to the correct board and it gave some errors regarding USB pins, so I thought I would check to see if it is even possible and if I just need to change the pins to something else. I can post those warnings if you want? I just need to recreate that error.

Best regards,

Sheldon

0 Sheldon Maciel over 8 years ago in reply to Sheldon Maciel

Intellectual 400 points

These are the errors I get. It is a lot more than I remember.

0 Amit Ashara over 8 years ago in reply to Sheldon Maciel

TI__Guru**** 244400 points

Hello Sheldon

Just because usb_otg_mouse example is listed it does not mean that it will work on the EK-TM4C123GXL. You must look at the full path of the example code base as given in "[...]" in front of the example name. That is the board the example is meant to work on.

0 Sheldon Maciel over 8 years ago in reply to Amit Ashara

Intellectual 400 points

Hello Amit,

Thank you, that was my fear. So I just need to use the example you suggested with my board and modify it to work with a USB mouse?

Regards,
Sheldon

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EK-TM4C123GXL: USB OTG Mouse Example - Hardware and Software Issues