Notes
    The pin numbering of the BS2sx is wrong - see Errata page.
circuit	multiprogs
-------	----------
1	BOStx		con	0	'pin serial to BOS processor
0	BOSrx		con	1	'pin serial from BOS processor
4	epower		con	2	'pin high turns on power to electronics
2	BOShalt		con	3	'pin high halts current BOS move 
3	BOSbusy		var	in4	'pin BOS processor busy => high
5	irrx		con	5	'pin infra red comms in, i96n
6	lcdtx		con	6	'pin to send to LCD
7	lcdrx		con	7	'pin to receive from LCD
8	Rled		con	8	'pin high turns on right green led
9	Lled		con	9	'pin high turns on left red led
	outRled		var	out8	'pin high turns on right green led
	outLled		var	out9	'pin high turns on left red led
14	ustx		con	14	'pin ultrasonic commands,	i96n
15	usrx		con	15	'pin ultrasonic data in,	i96n
    The switch SW1 is after the 1A fuse not before.
    Feelers J19 should be J17.
    The Servo volotage dropper diodes are BYW80.
    The relay back emf diodes are 1N4001.
    The 5v regulator capacitors are both 220uF.
    Revisions
    27-07-2011 Electronics reverse voltage diode 1N4001 added from 10A fuse to before 1A fuse - hand modification to PCB.
        Electronics supply now comes direct from 10A fuse through the 1N4004 isolating diode.
    27-07-2011 5v regulator changed from 7805 to LM2940 LDO 5v 1A regulator.
    27-07-2011 added 4700uF from the SW1 input to ground.