interfacing tips for i2c based mcp23016

[arbj2]

hi,

I am trying to interface the mcp23016 port expander with my beaglebone black computer. I have seen some tutorials on i2c interfacing on the beaglebone black. However my problem is getting the interface to work on different voltage levels.

My existing circuit uses two mcp 23016 ics that run on 5 volts dc, the connections to the port are also 5 v based, these are a matrix based keypad and a lcd panel with parallel interface.

As the beaglebone black can accept only 3 v signals, is it possible to pull up the i2c pullup resistances to 3 v instead of 5 v so that signals to and from the device are at 3 volt levels?

Basically i want to know if the mcp can operate on 5v dc level but the pullup to the i2c pins are pulled to 3v levels ?

Please help.

thanks
a

 

[embpic]

try any CMOS base i2c or check wheather this port-exp support this voltage or not.