More code

This will assume the wiimote has a motionplus attached - if it doesn't, no cwiid.MESG_MOTIONPLUS events will be recorded, and it will just plot the three graphs for the accelerometers rather than the five for accelerometers and motionplus.

#!/usr/bin/python

import cwiid
from time import time, asctime, sleep
from numpy import *
from pylab import *

def plotter(plot_title, timevector, data, position, n_graphs):
   subplot(n_graphs, 1, position)
   plot(timevector, data[0], "r",
        timevector, data[1], "g",
        timevector, data[2], "b")
   xlabel("time (s)")
   ylabel(plot_title)

print "Press 1+2 on the Wiimote now"
wiimote = cwiid.Wiimote()

# Rumble to indicate a connection
wiimote.rumble = 1
print "Connection established - release buttons"
sleep(0.2)
wiimote.rumble = 0
sleep(1.0)

wiimote.enable(cwiid.FLAG_MESG_IFC | cwiid.FLAG_MOTIONPLUS)
wiimote.rpt_mode = cwiid.RPT_BTN | cwiid.RPT_ACC | cwiid.RPT_MOTIONPLUS

print "Press plus to start recording, minus to end recording"
loop = True
record = False
accel_data = []
angle_data = []

while (loop):
   sleep(0.01)
   messages = wiimote.get_mesg()
   for mesg in messages:
       # Motion plus:
       if mesg[0] == cwiid.MESG_MOTIONPLUS:
           if record:
               angle_data.append({"Time" : time(), \
                   "Rate" : mesg[1]['angle_rate']})
       # Accelerometer:
       elif mesg[0] == cwiid.MESG_ACC:
           if record:
               accel_data.append({"Time" : time(), "Acc" : mesg[1]})
       # Button:
       elif mesg[0] == cwiid.MESG_BTN:
           if mesg[1] & cwiid.BTN_PLUS and not record:
               print "Recording - press minus button to stop"
               record = True
               start_time = time()
           if mesg[1] & cwiid.BTN_MINUS and record:
               if len(accel_data) == 0:
                   print "No data recorded"
               else:
                   print "End recording"
                   print "{0} data points in {1} seconds".format(
                       len(accel_data), time() - accel_data[0]["Time"])
               record = False
               loop = False
       else:
           pass

wiimote.disable(cwiid.FLAG_MESG_IFC | cwiid.FLAG_MOTIONPLUS)
if len(accel_data) == 0:
   sys.exit()


timevector = []
a = [[],[],[]]
v = [[],[],[]]
p = [[],[],[]]
last_time = 0
velocity = [0,0,0]
position = [0,0,0]

for n, x in enumerate(accel_data):
   if (n == 0):
       origin = x
   else:
       elapsed = x["Time"] - origin["Time"]
       delta_t = x["Time"] - last_time
       timevector.append(elapsed)
       for i in range(3):
           acceleration = x["Acc"][i] - origin["Acc"][i]
           velocity[i] = velocity[i] + delta_t * acceleration
           position[i] = position[i] + delta_t * velocity[i]
           a[i].append(acceleration)
           v[i].append(velocity[i])
           p[i].append(position[i])
   last_time = x["Time"]

n_graphs = 3

if len(angle_data) == len(accel_data):
   n_graphs = 5
   ar = [[],[],[]] # Angle rates
   aa = [[],[],[]] # Angles
   angle = [0,0,0]
   for n, x in enumerate(angle_data):
       if (n == 0):
           origin = x
       else:
           delta_t = x["Time"] - last_time
           for i in range(3):
               rate = x["Rate"][i] - origin["Rate"][i]
               angle[i] = angle[i] + delta_t * rate
               ar[i].append(rate)
               aa[i].append(angle[i])
       last_time = x["Time"]


plotter("Acceleration", timevector, a, 1, n_graphs)
plotter("Velocity", timevector, v, 2, n_graphs)
plotter("Position", timevector, p, 3, n_graphs)
if n_graphs == 5:
   plotter("Angle Rate", timevector, ar, 4, n_graphs)
   plotter("Angle", timevector, aa, 5, n_graphs)

show()