A:0:15			set ADC 0 to amplitude 15
L:[0-7]:800:512:1023:0	set RGBX amplitude. Precision is lost somewhat if phasing
B:[0-7]:[0-255]		set LED to blink, with duty cycle. 255->100%, 0->0%
I:[0-7]:[2-4]		set LED to phase in and out, with gamma. 0 is linear, 2->1.8, 3->2.0, 4->2.2
P:[0-7]:[0-255]		set LED phase offset
T:[0-255]		set current phase angle
F:[10-65535]		set period (not frequency)
S			power save. turn off all LED's, sleep MCU
N.*			nop - used for waking MCU, since chars are likely to be lost.
X			return performance information
E[0-255]		echo - sends back the same number



All operations end with \n
MCU responds with "0\n", where 0 is
	0	success
	1	unknown command
	2	invalid argument (wrong number of arguments, non-number in argument, too big argument)
	5	I/O error (buffer overrun, parity error, frame error, etc.)
	6	internal error
	7	misc. error
	8	last command was lost, because MCU just woke up
	9	success - for sleep command (don't send any commands for at least 10msec after receiving this code)
	10	success - with colon separated parameter[s]
	11	mcu starts up
MCU always issues a one line response, even if the operation was "nop" ("N.*")