Added example for migpic's "Pancake maker". Shows how to move motors independently.

Author: marcusw

examples/cnc.py

@@ -0,0 +1,53 @@
+#Script to control a NXT 2-axis CNC "Pancake maker"
+#Illustrates controlling more than one motor at the same time without trying to
+#sync them. Uses the thread module.
+#Written 2/3/11 by Marcus Wanner
+#
+#For more info and warnings see:
+#http://groups.google.com/group/nxt-python/browse_thread/thread/f6ef0865ae768ef
+
+import nxt, thread, time
+b = nxt.find_one_brick(name = 'MyNXT')
+mx = nxt.Motor(b, nxt.PORT_A)
+my = nxt.Motor(b, nxt.PORT_B)
+motors = [mx, my]
+
+def turnmotor(m, power, degrees):
+	m.turn(power, degrees)
+
+#here are the instructions...
+#the first value is the time to start the instruction
+#the second is the axis (0 for x, 1 for y)
+#the third is the power
+#the fourth is the degrees
+#it's probably not a good idea to run simultaneous turn
+#functions on a single motor, so be careful with this
+instructions = (
+	[0, 0, 80, 360],
+	[0, 1, -40, 1080],
+	[1, 0, -80, 360],
+	[2, 0, 80, 360],
+	[3, 1, 100, 360],
+	[3, 0, -100, 360],
+)
+#how long from start until the last instruction is ended
+length = 5
+
+def runinstruction(i):
+	motorid, speed, degrees = i
+	#THIS IS THE IMPORTANT PART!
+	thread.start_new_thread(
+		turnmotor,
+		(motors[motorid], speed, degrees))
+
+#main loop
+seconds = 0
+while 1:
+	print "Tick %d" % seconds
+	for i in instructions:
+		if i[0] == seconds:
+			runinstruction(i[1:])
+	seconds = seconds + 1
+	if seconds >= length:
+		break
+	time.sleep(1)