No, I'm saying you can't send I2C one meter off-board. Even six inches in anything but a gentle EMC environment can be severe trouble without careful design. And yet I've seen people try to run it ~180cm next to horrifying noise sources. Surprise, surprise, that doesn't work out very well.
The root of the problem is that I2C has serious EMC immunity issues. It's well known and appreciated that its drive is weak and open-drain. The bus buffers and especially differential drivers can and do help there. (And will get you past a meter.) What's less well recognized is that a single glitch pulse on SCK knocks all the internal state machines out of whack and requires a bus reset to fix them. Hope you're doing that when your bus is idle or when you're getting anomalies! Most people don't. The Nexus 4 phones sure didn't; this is why their light sensors went dead or crazy or both after a while of uptime.
All of that gets easier to handle if there's a nice, big, low-impedance ground plane nearby, which is why you don't see so much trouble when it stays on the PCB.
The root of the problem is that I2C has serious EMC immunity issues. It's well known and appreciated that its drive is weak and open-drain. The bus buffers and especially differential drivers can and do help there. (And will get you past a meter.) What's less well recognized is that a single glitch pulse on SCK knocks all the internal state machines out of whack and requires a bus reset to fix them. Hope you're doing that when your bus is idle or when you're getting anomalies! Most people don't. The Nexus 4 phones sure didn't; this is why their light sensors went dead or crazy or both after a while of uptime.
All of that gets easier to handle if there's a nice, big, low-impedance ground plane nearby, which is why you don't see so much trouble when it stays on the PCB.