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Another USB not recognized ATMega168PA

Posted: Tue Jun 19, 2012 9:56 pm
by Xaser
Hi everyone,

I'm currently working on a little project to see if V-USB & BootloadHID can be used for a bigger project as well. the current Circuit is quite simple: http://i.imgur.com/Qtgyg.png

I use an Arduino as ISP programmer and the uc still works (i just managed to run a blink program which i flashed to the bootloader start address at 0x3800). However when i put my UC in the USB Circuit, and plug it in, my System (Win7 Prof, x64) won't recognize it (well once it kinda did by at least saying unknown device).

I compiled the Firmware using WinAVR which gave me these warnings:
usbdrv/usbdrv.h:213: warning: 'usbFunctionDescriptor' used but never defined
usbdrv/usbdrv.h:220: warning: 'usbSetInterrupt' declared 'static' but never defined

I flashed it not using make but AVRDude as this worked better using the ArduinoISP.

My Fuses are:
Low: 0xDD, High: 0xDF, Extended: 0xF8

I also measured the potential differences around the circuit while it was plugged in and i measured constant 2.8V between D+ / D- Ports on the ATMEGA and the USB cable D+ / D- (if that makes sense)

I'm pretty certain my configs are right, however just to be sure, here they are as well:
bootloaderconfig.h: http://pastebin.com/uUC31H9w
makefile: http://pastebin.com/Y7cknCtL
I didn't change anything else.

That's all the information i can give you and i have no idea what to do anymore. The circuit seems solid, the bootsector address and fuses set correctly.

The only thing i'm unsure about is: Do the zener diodes have to have the ring pointing "towards" the data lines or towards the ground. (if you get what i mean)

Regards,
Xaser

Re: Another USB not recognized ATMega168PA

Posted: Tue Jul 24, 2012 5:53 pm
by ulao
I'm pretty cretin pico Chips gives troubles on the 168's... Also are you using 1/2 watt diodes ?