Arduino Master-Slave Pins

Question

Can I change the pins on the communication for a Master-Slave arduino Wire transmission? I want to communicate between 2 arduinos, but on one of them A4&A5 are taken

Answer 1

You cannot. Wire uses hardware I²C, and on the Uno only A4 and A5 are connected to the TWI peripheral on the MCU. You will need to either switch to a bit-bang I²C implementation or change the protocol you're using.

Answer 2

To complete Ignacio's answer, there's indeed no other hardware I2C on AVR Arduinos.

The only options you have to use other pins is:

• to use bitbang i2c, which is way slower ;
• or you can switch to the Arduino Due which features two TWI ports ;
• or you can use an SPI to I2C serial bridge such has that one.