Ramps 1.4 expansion via i2c?

Looking around the net trying to figure out some stuff that i could possibly do to upgrade my 3d printer and was wondering...
What stops us from expanding the number of stepper motors we can use by using an I2C compatable stepper motor controller and/or expansion board?
All i've seen with I2C and ramps is that people are just using it to control an LCD display...
Heck, I2C seems to be able to control more than one device at a time so you can attach a stepper motor controller, a fan controller, AND an LCD display at the same time.

Any thoughts to this?

You could, although I would be surprised if you could get reason performance out of it due to latency, available bandwidth, and protocol overhead.

i dont think it would be that much of an overhead as the expansion board will have a few commands to deal with.
pretty much, turn extruder x on, extruder x motor rotate y steps, and so on.
personally not at the point where i can effectively make the board myself but it's an idea that threw out so that others with more skills than me can take a look into it.

so i found some good info on I2C.
[www.neufeld.newton.ks.us]
And apparently Texas Instruments sell off I2C chips. [www.ti.com]
I2C can possibly be used to create a simple and yet customizable electronics board for 3d printing with a mix and match type system.

Edited 1 time(s). Last edit at 07/07/2015 06:38PM by alatnet.

Quote
alatnet
i don't think it would be that much of an overhead as the expansion board will have a few commands to deal with.
pretty much, turn extruder x on, extruder x motor rotate y steps, and so on.

It's not that it can't be done. It can. But I don't think you're considering the whole process as a complete machine. If all you were doing was controlling functions where precise timing wasn't needed (turning on a fan, light, heater, etc) then yeah, you could use it to expand. But once you get into controlling steppers, things get a lot more complicated as steps between motors needs to be timed precisely, something I'm not sure i2c would be good at.