topic twr_k64 demo USB example in Kinetis Microcontrollers

twr_k64 demo USB example

kooroshhajiani — Mon, 04 Apr 2016 22:57:35 GMT

I have tried to run the USB CDC HOST and CDC DEVICE demo in SDK 1.3 , using 2 TWR_64K and KDS3.0 with no luck. I just pass the initialization phase and DEVICE is never attached. A very gracious user named ISSAC has been helping me tremendously but it just refuses to attach the device. If any one have some thoughts, Please let me know.

So I decided to run the similar demos Freescale_BM_USB_Stack_v5.0 using IAR platform.

I'm trying to build the project from the following folder:

C:\Freescale_BM_USB_Stack_v5.0\Src\example\host\cdc\cdc_serial\bm\iar\host_cdc_serial_twrk64f120m

So created a wok-space and had to add few include path This is what I get:

It is passing the compile phase however it fails in the linking phase since its looking for a library file usbh.a

in the folder shown in the output council of the workbench that does not exist . where is this file?

Any Ideas? Anyone?

Thanks,

Koorosh Hajiani

Re: twr_k64 demo USB example

isaacavila — Tue, 05 Apr 2016 16:39:33 GMT

Hello Koorosh,

In USB Stack 5.0, you need to compile USB library for your host application, it is located at: <Freescale_BM_USB_Stack_v5.0>\Src\usb_core\host\build\iar\usbh_bm_twrk64f120m. After building the USB Host library, you will be able to compile your project correctly.

Hope this helps!

Regards,

Isaac

Re: twr_k64 demo USB example

kooroshhajiani — Tue, 05 Apr 2016 16:53:42 GMT

Thanks Issac.

Yes you’re right, I forgot to do that.

Regards,

Koorosh

Re: twr_k64 demo USB example

kooroshhajiani — Thu, 14 Apr 2016 21:52:09 GMT

Hi Isaac;

I had to leave USB implementation for a while to do some other embedded task and now I'm back again.

So I was able to get the HOST from:

C:\Freescale_BM_USB_Stack_v5.0\Src\example\host\cdc\cdc_serial\bm\iar\host_cdc_serial_twrk64f120m

to attach the device from SDK:

C:\Freescale\Freescale USB Stack v4.0.3\Source\Device\app\cdc\iar_ew\kinetis_k20

Now as you know I'm a novice when it comes to USB. So my goal is to send just a few bytes from host to device and visa versa .

I see a function named

_io_cdc_serial_write_async ,Is this the function to call for that purpose? I placed a break point on this function but it never hits.

one last thing when I type characters in my terminal before I press enter, They're echoed back on screen My local echo on my terminal is off.

Thanks,

Koorosh Hajiani

Re: twr_k64 demo USB example

isaacavila — Thu, 14 Apr 2016 22:37:45 GMT

Hello Koorosh,

About characters being echoed, in cdc_serial.h there is a macro to enable/disable echo in serial terminal:

#define CDC_SERIAL_ECHO_BACK     (1)

So you need to set it to 0 in order to disable echoing back.

For CDC example, progam is reading data from UART (serial terminal) and they are stored in a buffer that will be sent to USB later. This data is sent by using:

num_done = _io_cdc_serial_write(s_f_usb_info.f_usb, &usb_tx_buf[usb_tx_done], (send_cnt > CDC_MAX_PKT_SIZE? CDC_MAX_PKT_SIZE : send_cnt));

In this case, s_f_usb_info.f_usb is the FILE PTR to write to USB module, usb_tx_buf[] is the buffer where the data is stored and third parameter specifies how many data will be sent.

I hope this can help!

Regards,

Isaac