USB : USB Classes    USB Classes for Microcontrollers  

What's going on here?  The CDC device driver is constantly requesting data from the device, hundreds of times in every 1 msec USB frame, that's what.  It's a (useless) conversation like this:

"Do you have anything for me?"

"How about now?"

"Not yet."

...and on and on, over and over, burning up 50% of the full speed USB bus bandwidth.

 What a waste! All that bandwidth gone, just to give you something that's no smarter than an old time serial port!


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