ATMEGA32A and VUSB

General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
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pjrpjrpjr

ATMEGA32A and VUSB

Post by pjrpjrpjr » Mon May 16, 2011 5:22 pm

I am having trouble with VUSB and an ATMEGA32A which is supposedly a drop in replacement for the ATMEGA32. I suspect it is the hardware interface. Has anyone used VUSB successfully with the ATMEGA32, if so what was the hardware interface circuit?

Daid
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Re: ATMEGA32A and VUSB

Post by Daid » Mon May 16, 2011 6:13 pm

I used the ATMega32A just fine for V-USB (with 5V hardware, no zeners). Just make sure you use the right crystal, and set the fuses right (some "A" parts have different fuse settings then the not "A" variants)

pjrpjrpjr

Re: ATMEGA32A and VUSB

Post by pjrpjrpjr » Thu May 19, 2011 9:54 am

Thanks for your response, great to hear it works. Can you point me to the hardware circuit you used please.

Daid
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Re: ATMEGA32A and VUSB

Post by Daid » Mon May 23, 2011 1:35 pm

I don't have the schematic at hand. But I only used a few components:
100nF to stabelize VCC
2.2k Ohm pull up from VCC to D-
470 Ohm from D- to INT1
470 Ohm from D+ to INT0
20Mhz XTal with 2x 20pF to ground

waiman
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Re: ATMEGA32A and VUSB

Post by waiman » Mon Jun 06, 2011 3:51 am

I have successfully V-USB to MEGA32A on, and successfully tested a number of V-USB Project :D

But I do not know how to upload files :(

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