Arduino on breadboard

Using Arduino General Electronics
#1

Hi everyone

Regarding to this TOPIC, I want to make two Arduino on the breadboard that communicate with each other via I2C protocol.
Can we use one crystal and a pair of 22Pf cap for two ATMEGA328P on breadboard?

Many thanks
Mahdiyar

#2

No; one crystal and load capacitors for each Arduino.

Or you can of course set them to run off the internal oscillator; a crystal is entirely optional.

#3

You can also look at the CKOUT fuse setting which propagates the clock signal on portB0.
The other mcu chip would also need a corresponding fuse change CKSEL to accept an external clock signal. Care is required to ensure you can always undo such changes.

#4

I want to make two Arduino on the breadboard that communicate with each other via I2C

I do that all the time. I do however have a crystal and caps for each.

@6v6gt’s idea of passing the clock between them is a good one - never thought of doing that.

However, with the different fuse settings, I feel adding a crystal is easier.

Ask if you need help with the I2C communication.

Willem.

#5

Get two Pro Mini clones and mount them on your breadboard.

#6