Xenocrates wrote:I support replacing the I2C with say, RSS485, run over a quarter mile spool of rusty barbed wire before it goes to the Rambo (I kid, but there are far more resilient standards, and something like RS485 is high enough data rate even at over a kilometer of length). I2C is a fine protocol for small runs, and in it's intended use case. On a board at the end of a multiple foot wire where it's next to a very electromagnetically noisy heater is not a use case that makes ANY sense for it. Admittedly, it's easy to implement, and there is a specific 4 pin connector on the full size rambo for it.
I2C was never meant for this kind of application. It literally means Inter-Integrated chip. I standard for talking between chips on a single board in close proximity.
One way to get past the length of the cable is simply to put the micro on the same PCB with the accelerometer, or really close to it on a separate PCB. In this case, I think the idea is to plug the CPU into the connector on the HE280 and use and endstop for the probe signal.
I suggest going one step further and include a spot on the PCB for an accelerometer to be populated. That way, the same board could be used for those without the HE280 by simply populating the part.
Also, there's no reason you can't have several screw patterns on the PCB so that it will mount to different hot ends by using the appropriate set of holes.