Thanks for your reply 
Ah, yes that’s correct. I’m always forgetting that point…
I really want to try out Multipass so I’m gonna try to set TT to follower and write a few strings on its OLED display. But for long term usage, it’s probably not very useful to use Teletype as a simple console output for OSC messages but at some point it could become useful to have the possibility to log a few messages though. I’m gonna try that.
Yes I can test that too. If the I2c bus can handle that, I want to see how the Rpi reacts to this and if there’s no issue between the two. I’m adding this possibility to the list too.
Today, I thought of another possibility: perhaps the easiest setup, something that would not waste all the potential of Teletype (both hardware and software) would be to keep the actual Teletype firmware, and to connect it to the second bus of the RPI. I could use Hans as a bridge between bus 1 and bus 2, this would prevent any multi-master issue. Not sure about the performances of such a setup but it’s worth trying.
I could also try the new generic i2c ops and have Teletype triggering scripts hosted on the RPI. Hans has no address but I can probably catch these i2c generic op “on the fly” on the RPI.