Overweight

Overall we want to measure when a rotating platform (10 cm height, 5 cm diameter) stops rotating.

We are using a QRD1114 that is a combination IR emitter & photodiode, and an arduino duemilanov, connected to a PC that would respond.

QRD1114

The actual circuit is taken directly from bildr:



Arduino is running just the example Analog reader (from pin 0, matching the diagram):

/*  AnalogReadSerial Reads an analog input on pin 0, prints the result to the serial monitor. Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground. This example code is in the public domain. */ // the setup routine runs once when you press reset: void setup { // initialize serial communication at 9600 bits per second: Serial.begin(9600); } // the loop routine runs over and over again forever: void loop { // read the input on analog pin 0: int sensorValue = analogRead(A0); // print out the value you read: Serial.println(sensorValue); delay(1);       // delay in between reads for stability }

PC is running the following just to show the measurements:

import pylab import matplotlib.pyplot as plt import serial from pylab import array s = serial.Serial('/dev/ttyUSB1', baudrate=9600) def get_line(s, count=10): ret = [] for i in xrange(count): l = s.readline try: f = float(l.strip) except: print "bad value %r" % l            f = 0.0 ret.append(f) return ret dat=[0,1] fig = plt.figure ax = fig.add_subplot(111) Ln, = ax.plot(dat, '.') ax.set_xlim([0,20]) ax.set_ylim([0,1100]) plt.ion plt.show while True: dat = get_line(s) a = array(dat) dat = array([sum(a) / len(a), 0, 0] + dat) #print ", ".join(map(str, dat)) Ln.set_ydata(dat) Ln.set_xdata(range(len(dat))) plt.pause(0.01)
 * 1) !/usr/bin/python

= Installing on windows, playing back movies in response to motion stopping = * http://gstreamer.freedesktop.org/data/pkg/windows/1.0.7/gstreamer-1.0-x86_64-1.0.7.msi * http://gstreamer.freedesktop.org/data/pkg/windows/1.0.7/gstreamer-1.0-devel-x86_64-1.0.7.msi

From Ipython installation site: * http://continuum.io/downloads.html

cmd
 * 1) pip install pyserial

install latest vlc

vlc -f file://c:/..

install arduino

had to reinstall driver twice (windows 7 64 bit?)