Multiple mcu-s

Nixa

I have an idea to build printer with multiple automaticly changeable extruders. Let's say 10 extruders. No arduino can support that because there is not enough analog inputs.
My idea is to move all slow responding units to separate mcu. All heaters, fans, sensors, servo motors, etc and connect mcu-s over serial. I gues it could use same type of communication as when connected to computer.
Since it would use one extruder at any given time, I would only need one extruder stepper motor output, and one per axis. Total four. But I would need to controll 10 extruder heaters, one heated bed, 10 extruder sensors, one heated bed sensor, 10 extruder cooling fans, one print part cooling fan, servo for bed leveling, and servo for tool (extruder) clamping.
(it doesen't have to be 10 extruders. It could be mill spindle, laser, punch engraver...)

I could use 2 analog inputs for, let's say bead and one extruder, and the rest of them on separate mcu.

Does this make nay sense???

RAyWB

there are 16 analog inputs on mega , 14 on due....
think what you mean is the pwm outputs are not enough.
look at sample events for more pwm outputs using an external device via I2C.
Using PCA9685 you can have 16 additional pwm outputs which should be enough.
extruder steppers could be driven by multiplexing step/dir inputs ,select by enable pins .
may be you describe a little better what you want to to so i´ll try to help you

Nixa

I want to make all-in-one multipe extruder printer (say 5 extruders), laser engraver/cutter and mini cnc mill with automatic tool changer.

RAyWB

ok, so here is all you need regarding pins

https://github.com/repetier/Repetier-Firmware/tree/development/src/SampleEventSystems/Laser%20PWM%20and%20DAC<br/><br/>