How to communicate via USB with Windows 7 device using Kinetis K20?

[hardeepsingh]

I would like to connect a tablet running on windows 7 with my own card which is built around Kinetis K20. Please suggest how should I interface both using USB.

Will my K20 support communication with a Windows 7 device?

[Hui_Ma]

Hi,

MK20 50MHz product provides USB Full speed controller, which can communication with PC (Windows 7 OS).

Freescale provides USB stack, the latest version is V4.1.1.

Customer can download it from below link:

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MEDICALUSB&fpsp=1&tab=Design_Tools_Ta...

After programed, MK20 can works as USB device, such HID mouse or CDC device communication with PC.

Wish it helps.

[Wayner]

Hello,

I have problems with USB device application on MK20 board, could you tell me how

to port the application code from MK40 which exists in USB Stack v4.1.1 to MK20?

What I have done is as follows, but it doesn't work.

Host USB: PC with Windows 7 OS

Slave USB: MK20

IDE: IAR Embedded Workbench for ARM V6.60.1.5104

Based Project: Freescale USB Stack v4.1.1/Source/Device/app_composite/msd_and_cdc/jar_ew/kinetis_40/USB_MSD_CDC.ewp

I changed very little from based projected for my board, which is:

1. Changed Processor variant setting to MK20DN512Zxxx10 which is used on my board in General Options of IAR.

2. Changed #include <MK40N512VMD100.h> to #include <MK20N512VMD100.h> in derivative.h file

3. Removed GPIO_Init().

4. Removed #ifdef MCU_MK40N512VMD100 pair in pll_init() function in main_kinetis.c

5. Modified #if (defined MCU_MK40N512VMD100) || (defined MCU_MK53N512CMD100) || (defined MCU_MK60N512VMD100) || (defined MCU_MK70F12)

  to  #if (defined MCU_MK40N512VMD100) || (defined MCU_MK53N512CMD100) || (defined MCU_MK60N512VMD100) || (defined MCU_MK70F12)

        || (defined MCU_MK20N512VMD100) in usb_devapi.h file

6. kept the same Linker configuration file, which is MK40N512VMD100_Flash.icf

What else needed to do?

Need your help. Thank you!

[Wayner]

Solved. It was a hardware problem. Thank you!

[dspNeil · Accepted solution]

Yes, this can be done, and is quite common. You really need to define how you need to interface (what USB class). You will need to operate the K20 device as a USB Device, not a USB Host, as the Win7 device will be the Host.

Have a look at the baremetal USB stack examples; there are many good examples that might do just what you need. Install the stack, and look through the documentation/examples: USB Stack Product Summary Page

Alternatively, you could use MQX if you desire an RTOS. There are many examples for this as well. Install MQX, and look through the documentation/examples: http://www.freescale.com/mqx