I want to connect multiple ATmega328P chips to an I2C bus. Each unit is configured as slave but can send/broadcast messages as master too.
I have this currently working with Arduino Nano units and this works fine.
To reduce cost and more importantly space, I want to replace the Arduino Nano's with ATmega328P chips.
Now, my question is, do I need external crystals for these ATmega328P chips for this multi-master configuration?
I know I2C is not time-critical such as RS232 because the slave follows the clock-line of the master (right?).
The only concern I have is: will collision detection work properly if two ATmega units without crystal start transmitting data at the same moment?