autocalibration with tiny45

General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
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butrus.butrus
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autocalibration with tiny45

Post by butrus.butrus » Tue Aug 12, 2008 4:55 pm

Hi!

I've tried the autocalibration from EasyLogger (I replaced the driver with the newest one, 2008-05-13), but it doesn't work. I however switched the D- and D+ (i.e. D- is PB2 and D+ PB0) and changed the usbconfig.h accordingly (I need to catch USB suspend).

In EEPROM the first byte is 0xfe after an attempt to autocalibrate...

Is this supposed to work (and there is some other hardware error), or the autocalibration isn't supported for switched D- and D+?

Thanks!

Petr

christian
Objective Development
Objective Development
Posts: 1443
Joined: Thu Nov 09, 2006 11:46 am

Post by christian » Tue Aug 26, 2008 6:29 pm

The auto calibration code does not cope with swapped D+ and D-. Simply modify the assembler routine usbMeasureFrameLength() to use the other data line. And check whether other parts of the auto calibration also refer to a data line...

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