topic CDC flow control on KL27Z256 in Kinetis Microcontrollers

CDC flow control on KL27Z256

shuichiy — Mon, 18 Jun 2018 08:24:34 GMT

Currently KL27Z256 works fine on CDC which communicates with Windows 10.

KL27Z256 transfers bulk data to PC, so I want to support flow control on KL27Z256 in case of overflow.

Unfortunately CDC examples on SDK 2.3 does not describe both hardware and software flow controls.

Is there any resolution for easy implementation of the features ?

Your any advice will be appreciated.

Re: CDC flow control on KL27Z256

mjbcswitzerland — Mon, 18 Jun 2018 13:16:24 GMT

In case of limitations you can also use the Open Source uTasker KL27 project - see the KL27 link below for CDC/multiple CDC including CDC<->UART bridges with full end-to-end flow control.

Regards

Mark

Build with: CW10.x, KDS, MCUXpresso, IAR, Keil, Greenhills, Crossworks, CooCox, Atollic, S32 Design Studio, GNU Make and Visual Studio

USB: http://www.utasker.com/docs/uTasker/USB_User_Guide.PDF
USB composites: http://www.utasker.com/kinetis/USB_Device.html
USB-CDC host<->device video: https://www.youtube.com/watch?v=XhISV1czIo4&list=PLWKlVb_MqDQFZAulrUywU30v869JBYi9Q&index=16

Free Open Source solution: https://github.com/uTasker/uTasker-Kinetis
Working project in 15 minutes video: https://youtu.be/K8ScSgpgQ6M

For better, faster, cheaper product developments consider the uTasker developer's version, professional Kinetis support, one-on-one training and complete fast-track project solutions to set you apart from the herd : http://www.utasker.com/support.html

Re: CDC flow control on KL27Z256

shuichiy — Thu, 28 Jun 2018 04:31:45 GMT

Mark,

Thanks for your response.

I have understood that external operating system is necessary for flow control.

However it is hard to change current project at this time.

Then I have one more question.

Is there any way to change CDC baud rate ?

I found following codes in virtual_com.h and changed 115200 to 2400, but unfortunately it affected nothing.

/* Currently configured line coding */
#define LINE_CODING_SIZE (0x07)
#define LINE_CODING_DTERATE (115200)
#define LINE_CODING_CHARFORMAT (0x00)
#define LINE_CODING_PARITYTYPE (0x00)
#define LINE_CODING_DATABITS (0x08)

Regards,

Shuichi

Re: CDC flow control on KL27Z256

mjbcswitzerland — Thu, 28 Jun 2018 09:19:35 GMT

Hi Shuichi

An operating system is not necessary - just some simple software control.

The following may help with your baud rate setting question: FSL_USB_STACK and Tera Term - as you will see it is probably not of any importance for your bulk communication case.

Unfortunately you are in a similar position to many developers who have already invested so much time trying to tune the examples that they can't justify a quick change to a complete solution (which would have slashed project time and costs). However, if you are in a clinch in a professional development you could request a free port of your project state (see http://www.utasker.com/services.html ) which would probably still reduce the remaining development effort substantially by giving you a complete solution with personal support.

Regards

Mark

uTasker - for more performance and faster, cheaper product development

Re: CDC flow control on KL27Z256

shuichiy — Fri, 29 Jun 2018 00:27:59 GMT

Hi Mark,

Thanks again.

I will think about what I should do at this time.
You comments are very helpful for me.