BootloadHID with ATmega8 schematic

6TIT · Post by **6TIT** » Mon Apr 21, 2008 11:43 am

Hello,

I've build a test-board with this schematic.
I regulated the data lines with two zener-diodes.

http://www.obdev.at/products/avrusb/bootloadhid.html

When I connect it to the pc he doesn't recognise him.
Now could it be that I need to regulate the supply voltage to 3.6 and not the data lines? Or could there be something else wrong ?

I've seen schematics where the supply voltage is reduced:
==> http://www.obdev.at/products/avrusb/hidkeys.html
==> http://www.obdev.at/products/avrusb/index.html
==> http://www.obdev.at/products/avrusb/hidkeys.html

I wish to know some opinions before I start changing things on my test-board.

Greetz...

The schematic I made:
==> http://www.avrfreaks.net/index.php?name ... ic&t=62894

Post by **christian** » Mon Apr 21, 2008 7:00 pm

The schematic should be OK, if the Zener diodes are OK. Please measure the voltage on D- with a voltmeter. It should be well above 2.5 V.

Guest · Post by **Guest** » Mon Apr 28, 2008 11:47 am

Its about 2.9V so thats correct.....

I programmed the bootloader again (with STK500)
(I didn't change anything in the firmware or such because I am using a regulary ATmega8)

but it still doesn't recognize the device.

Any Idea's left :cry:

?

Post by **christian** » Mon Apr 28, 2008 4:06 pm

Did you check the obvious things:
- fuse bits
- hardware configuration reflected in bootloaderconfig.h
- compiled for correct clock rate
- boot loader enabled by jumper