--- In [email protected], "Nico Vanslambrouck" <[EMAIL PROTECTED]> wrote: > > Hi, > > Be aware the value of the pull-up resistors (in combination with the overall capacitance of the connected devices) defines the rise and fall times of the signals on the IIC communication bus. > And these rise and fall times are in direct relation with the maximum communication speed possible. > > In short: the lower the bus capacitance and pull-up resitor value, the faster the communication speed allowed on the bus. > BUT, there is a limit: be aware of the specification about maximum allowed sink-current of each single device . > > Kind regards, > > Nico
Hi Nico, You're correct. That's why on average a pull-up resistor with a value of 4k7-5k6 is a good choice for most situations. Having long wires (= increasing the bus capacitance) is anyhow devastating for I2C, unless you're using an I2C buffer, specially designed to transfer I2C communication over somewhat longer distances. Best rgds, --Geert
