Single data line tap

[Scarr]

Hi all,

is there a simple circuit that will allow me to watch each side of a IC2 type communication on separate lines of a logic probe so I can determine who is sending what? another way of putting this is to say if I had an IC on my left and one on my right connected via I2C, I want to see "only" the Left IC's output on one probe and "only" the rights output on another.

Thanks

Steve

 

[Pommie]

Due to the way I²C works you can't tell which device pulled the line low. It may be possible with additional circuitry but I think it would be complicated.

Surely the data itself will allow you to establish which chip was sending.

Mike.

 

[MikeMl]

The differential voltage across a resistor in-series with the data line should tell you which end of the resistor is driven...