AVR-Chat

> Dave Hylands
> Vancouver, BC, Canada
> http://www.DaveHylands.com/
>
Dave,

The standard bus speed for I2C is 100khz, fast speed is 400khz and high 
speed can go to 3.4mhz with some parts but the 200ns you suggest makes 
state changes at 5mhz. More in the realms of an SPI interface.

Part of the problem with I2C and speed is the drivers (if your using 
any) are bidirectional (like P82B715). There is a loop back path with 
delays. Add optos to that if you want isolation and you relly start 
hitting brick walls with the speed. 

Slow it down. 

Cheers
Stefan