AVR crashed and reboots

General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
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sid
Posts: 2
Joined: Thu Sep 17, 2009 8:56 pm

AVR crashed and reboots

Post by sid » Thu Sep 17, 2009 9:33 pm

Hallo,

I have a problem with the V-USB lib. I am especially interested in HID and boot-loader programs.

My hardware setup:
-Atmega644 @ 12Mhz; 4,2V (it's running stabile)
-USB pins pulled down with 3V6 Z-diodes according to the specs (D2, D3)

I did nothing else but downloading different projects and reconfiguring them for my hardware. But nothing seems to work. The controller simply always crashes and reboots for the boot-loader apps. I have absolutely no clue why. Syslog always reports:
usb 1-6.1.3: new low speed USB device using ehci_hcd and address XXX

I tried also two HID programs. Syslog recognizes both correctly as HID keyboards including the correct additional information of the programmers. Therefore I think the hardware is set up correctly. But as so as I tried to submit a char it crashes and reboots again. (Only once I was able to do so, but only for exactly one char)

Is their a problem if I use a Atmega644@12Mhz? Because I only found one app using an Atmega644. But for this app the controller is clocked with 20Mhz. If I recompile it with 12Mhz and it crashed. (I cannot try it with a 20Mhz crystal)

What am I doing wrong? Please help me. I am getting slightly mad.
Juergen

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