TWR_K20D50M - USB device

[mjbcswitzerland]

Hi All

Has any one tried USB device on the TWR_K20D50M board?

I found that this was not working with a driver used on K40, K60 and K70 boards. Initially I didn't think much of it due to the fact that the 50MHz Kinetis is rather different from the other ones (it has no memory protection unit, it has different interrupt IDs, its touch sensor controller has only one threshold register - were a few which meant adjusting things to get basic operation again) but I then tried the example in the KINETIS_50MHZ_SC package to see whether it would show me what is different in the USB and it also didn't work.

The basic problem seems to be that the USB_DP line's pull-up doesn't get set so the USB host doesn't see it being connected. The code is setting this as in all other Kinetis devices but if I measure the signal on the line it is staying at 0V.

I am wondering whether any one can confirm this, or do I have a problem with my board?

Regards

Mark

[PaoloRenzo]

Hi Mark

Do you have jumpers in J30 set?

5-6 (USBREGIN)
1-2

This might help

[carlhewitt]

Yes, this solution does make USB devices function properly on the TWR-K20D50M board.

It would probably be helpful to include this bit of information somewhere in the documentation for the K20D50M board.  It took us about a week to figure this out and finally stumbled upon this answer.

That said, we are grateful for the post.

[mjbcswitzerland]

Hi

Thanks, one of the jumpers was indeed missing. After adding it and adjusting the setting of the bus master (for USB access directly from FLASH - this bus master channel changes between devices) all seems to be OK.

Regards

Mark