Could not send 64 bytes of data through K20 USB

d_dinesh_k — Thu, 31 Jan 2019 10:51:02 GMT

Hi,

I am using Kinetis K20 USB for data transfer but while trying to send exactly 64 bytes of data from K20, the data is not being sent out of USB. On sending less than 64 bytes of data, the data transfer is working fine.

Is there any limitation on sending data at 64 bytes in K20 USB ?

Regards,

Dinesh Kumar

Re: Could not send 64 bytes of data through K20 USB

mjbcswitzerland — Thu, 31 Jan 2019 16:04:24 GMT

Hi Dinesh

If you are using 64byte endpoints to send data over an endpoint of length 64 you probably need to send an addition a zero length frame for that the USB host understands that the "complete" date has been received and should be processed.

Very probably the data has been sent but your host is not yet treating it - this is typical of USB-CDC, for example, and USB stacks that don't do this automatically for the user.

Regards

Mark

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- http://www.utasker.com/kinetis/tinyK20.html
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

topic Could not send 64 bytes of data through K20 USB in Kinetis Microcontrollers

Could not send 64 bytes of data through K20 USB

Re: Could not send 64 bytes of data through K20 USB