Memos From the Cube

Today I added the twenty-second demo to the MyUSB project; a CDC host demo. It’s very basic: enumerated CDC devices using the ACM profile have their sent data relayed through the serial port. Think a reverse USB-Serial converter, where an actual USB-Serial converter device plugs into the USB AVR (forming a RS-232 to logic level serial converter, using USB as the transport). I haven’t been able to properly test it however, as all my converters report non-standard class/subclass/protocol values in their descriptors to force the use of their vendor-specific drivers. That’s progress for you; create a defined class to allow different vendors to supply devices which can be driven from a common driver, and they’ll find a way to cock up the implementation.

Speaking of mistakes, I also fixed the AudioInput demo for the next version. The supplied code can’t possibly work (endpoint is created using the wrong direction token, the sample timer is continuously reset because I forgot to set the HasConfiguredTimer flag), yet I remember testing it; I suspect I just had the PC set to the wrong input source and was actually seeing data from my laptop’s internal microphone. Go figure. The updated code will be in the next MyUSB version release, a while from now. As always, if you need the updated code right this minute, send me an email.

EDIT: Neat, my 127th post, the maximum positive value of a signed 8-bit integer. Although I always thought I’d have at least one regular reader by the 100th post…