This is a simple example of INDEPENDENT management of 3 stepper motors.

You can connect up to 256 devices to common UART line
To work with them use simple protocol: 
	- each byte have 8 bits of data and nineth control bit
	- inactive modules don't read bytes with nineth bit == 0,
		only active module reads them
	- all modules send data with nineth bit == 0
	- to activate module simple send its number with nineth bit == 1
	- you can change module number (value will be stored in flash memory) by command 'N'
		and get its current number with command 'n'

All motors have independent lines DIR and CLK and common line EN.
Motor selection performed by setting to 1 corresponding EN pin.
Communication with MCU realized through simple USB<->TTL converter.
Just connect lines Rx/Tx of converter to Tx/Rx of evaluation boart,
connect together lines GND and +3.3V.
Communication speed: 57600, proto: 8N1
Comminication with MCU don't need special soft: you can even run screen session
or some terminal client like _com_. Another variant is a simple client - client-term.
MCU itself can print to terminal a short help about its protocol, just sent letter 'h'
to it.

You can connect up to 4 (5 for motor 0) end-point switches for each motor.
There's an ability to move till certain EP switches value, also you can move
motors infinitely (for now it realized only for all motors simultaneously).
