I'm looking to build a pretty basic project that relies on several submodules that use I2C for communication. I'm trying to find the smallest, cheapest AVR device that supports I2C. I know the 328P has a built in I2C interface, but I really don't need the 20 something other pins. Can anyone point me towards something more like an ATtiny that has a built in I2C interface?
My goal is the smallest, cheapest AVR without relying on software IC2 implementation.
Best Answer
A quick parametric search on Digikey shows that the ATTiny20 is the cheapest AVR with dedicated I2C capabilities in one-off quantities. Note that the ATTiny20 only provides hardware slave support, master TWI/I2C still needs a software implementation.
A slight step up is the ATTiny25 which has both master and slave TWI/I2C support, but operating in master mode the clock generation I believe has to be generated in software.
For complete TWI/I2C support, take a look at the ATTiny48.