Virtual com port for USB CDC is not enumerating for FRDMK20D50M

[harshaldalal]

HELLO,

I'm very new to freescale, 2 days back I received FRDMK20D50M board. I followed quick start guide and install P&E driver as well as update application. I tried Blink_rgb_freedom.srec example and serial_test_115200.srec precompiled examples from Quick Start Package by simply copy-paste in MSD and its working perfectly. In future I want to make my custom board which must communicate through USB CDC hence I'm trying to communicate over USB CDC (USB of target MCU Mk20DX128VLH5).

But in Device manager of windows 8.1 its not showing any hardware detect or Com port.

Is there any way to enumerate USB CDC or does any one have binary(.elf) file or driver which initiate serial communication over USB?

Thank you

HD

[isaacavila]

Hello Harshal,

I have tried by downloading USB CDC Device project that is included in KINETIS_50MHz sample code (you can download here: K20_50 |Kinetis 20 50 MHz MCUs|Freescale over Lab and Test Software section)

Once you download this project, be sure to select the configuration for FRDM-K20D50M (it is also compatible with TWR-K20D50M).

It worked well on Windows 7 64 Bit Host PC. Maybe you can try this code that also include its USB CDC Driver. Output file is also attached for your reference.

I hope this can help you,

Best Regards,

Isaac

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[harshaldalal]

Hi Isaacavila,

Thank you for your replay, I'll test it and will replay you soon..

thanks

Harshal Dalal.

[BlackNight]

Hello HD,

it might depend on the USB CDC stack/implementation you are using if and which device driver is needed. But by default, if you get the FRDM-K20D50 board out of factory, there is only a MSD bootloader on it, no USB CDC or debug interface. You need to upgrade the firmware/bootloader, however you need a Windows machine to do this, as the bootloader installed by the factor is not compatible with Windows 8. See FRDM Board Bootloader fails with Windows 8.1 Preview | MCU on Eclipse  and Illustrated Step-by-Step Instructions: Updating the Freescale Freedom Board Firmware | MCU on Eclips...

I hope this helps,

Erich

[harshaldalal]

Hey thanks Erich for your fast reply as well as yours wonderful and details blogs.

Honestly I buy this board by referring your blog only, they really helpful for newbie like me.  

now what you have suggested to update firmware/bootloader  was already successfully completed. please refer following image of SDA_INFO.html

I started with teensy3.1 which has MCU(Mk20DX256VLH7) of same series, I develop very stable firmware by teensyduino (Arduino Add on) which also giving accurate results for my project. Now I have to integrate all pcbs including teensy. when I build my code, teensyduino generate .elf file for particular code, and by referring your document and search I came to know that I can flash my code to my custom board with openSDA of FRDMK20D50M and USBDM.

Yesterday I developed Blink.cpp.elf file for simple blink LED code from teensyduino IDE and Flash that file in Target on-board MCU with help of USBDM and its working perfectly. I have not tried on my custom board yet, but I guess It also work by doing some hardware changes on board (cutting J11 i.e. Swd_clk).

my end application firmware will only includes SPI and UART over USB-CDC. Hence I also tried by flashing .elf of Uart code in same way as above but its showing like usb device descriptor request failed when I connect to USB-CDC mini usb as shown in fig.  

Also when I simply tried with blink LED. elf at that time it does not show any hardware changes in device manager.

So in summery my open SDA USB virtual com port is enumerate successfully but it fails with USB-CDC.

Thank you

HD