I2C-Bus Sniffer

Was bitte ist ein I2C - Bus Sniffer?

falls es jemanden interessiert, man weiss ja nie :-)
hier gäbe es noch die variante, wo man ein parallelport
stecker 3 kabel und ein linux pc benötigt ;-)
hab dafür extra mal linux installiert als ich etwas
debuggen wollte. und hat seinen zweck wunderbar erfüllt.

http://warmcat.com/milksop/cheapi2c.html

gruss fabian

Hi

I am trying to understand the code of the AVRFreaks project I2C Sniffer
(http://www.avrfreaks.net/modules/FreaksFiles/files/566/DN_048.pdf) but
I am too "green" to understand everything and I hope that there is
somebody who can help me.

1st question (concerning the I2CRead-function):
char I2cRead(void) {
#asm
mov r30,r2
#endasm
}
Why is the programmer copying r2 to r30 ? This function returns one
char bit when following is executed: I2CByte = I2cRead(); Can somebody
approve this ? But it does not make much sense to have only one bit in
the I2CByte.... ????

2nd question:
Why does the programmer initialize the Timer/Counter ? I cannot see any
usage of the Timer/Counter........

I highly appreciate every help from you.....

Thanks a lot.
shorsh

Here is the answer:

http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=40694&highlight=