arduino as a bridge between two i2c masters

Hey everyone, so I am gonna just jump right into the topic. Recently, I have been trying to build a project where I need to connect an ev3 to a raspberry pi. I have decided doing it by i2c after reading (and successfully replicating) an article about connecting an ev3 to arduino by i2c Connecting the EV3 and the Arduino - Dexter Industries. However, after setting it up with raspberry pi, I realized a huge problem that I am facing, both of these devices acted as masters and I could not get them to connect to each other. So I decided to use an arduino between those two which transports the data that it receives to the other device, which I couldn’t get working. I have no idea how to get it working anyways, it was just a hopeless try. Now I am doubting myself If I can’t do it. So my question is, is such a project possible or should I just give up. If I should, what type of communication do you suggest that I use.

I want to paint a joke about five, what is the length of water ? That is the kind of thing that you are asking :o Your doubts are for sure justified.

The normal Arduino Uno can be at only one I2C address, and multiple Masters might cause a collision.
You have the EV3 with Arduino working ? That is great :smiley: Let's keep that as it is.

I can think of only two solutions:
Use serial communication between the Raspberry Pi and the Arduino.
Use a second Arduino board with the Raspbarry Pi and use serial communication between the Arduino boards.

The Arduino Leonardo or (Pro) Micro has a spare serial port. That makes this easier.

I don't know the EV3, does it have other possibilities than a I2C Master ?

You also asked this question on stackexchange. Can the Raspberry Pi be set as I2C Slave ? Please keep us updated and give a link to your question once it has been migrated to the Rapsberry Pi Stack Exchange.

Wow, thanks for the quick answer, I migrated it to the raspberry pi stack exhcange here [url=https://raspberrypi.stackexchange.com/questions/84851/connecting-raspberry-pi-with-ev3-using-i2c[/url] which I hot an answer saying that it can in fact be used as an i2c slave using the pigpio library.

Thanks Kopel, I mean I have never though of a serial connection between the two but it should work and since I have experience on it, I should get it working pretty easily. So again, thanks a lot, you saved my life.