I'd like to show you how to use our LabQuest Stream sensor interface to
collect and analyze data from an iPad. LabQuest Stream is a special hardware
device that allows Vernier sensors to interact with your iPad using Bluetooth
wireless technology. Now, with Stream you can collect data from three analog sensors
and two digital sensors simultaneously, and you can analyze this data on your iPad
using our free Graphical Analysis app. Well, LabQuest Stream is battery-powered,
so let's get started by turning it on. Now, after I press the Power button, the
power LED will turn green and the Bluetooth LED will start flashing. This
lets you know that it's ready for a connection. Now, if I don't connect to my
Stream within 10 minutes, it'll automatically turn itself off in order to
save battery power. But before I go any further, I'm going to flip my LabQuest
Stream over, and make note of the serial number that's on the back. This number is
part of a unique name that helps you identify your Stream when you're trying to
connect to it from our software. Now, for my first example I'm going to show you how
to graph position versus time using our motion detector. Now, our motion detector
is a digital sensor, so I'm going to plug it into Digital Port 1 on my LabQuest
Stream. Next, I'm going to go to my iPad and start up Vernier's Graphical Analysis
app. Inside Graphical Analysis, I'm going to create an experiment and select
LabQuest Stream as my data source. Now, the iPad is going to go out and query all
of the available LabQuest Streams in your classroom. But we already know that ours
is numbered 1629, so we can go ahead and connect to it right away. Well, Graphical
Analysis automatically figured out that I have a motion detector connected, so it
set me up with a default graph. All I need to do now is move my hand up and down over
the sensor and collect some data. There I have a nice position versus time plot of
my hand motion. Well, LabQuest Stream can also collect data from multiple sensors at
the same time. This is critical when you need to time correlate events, such as
force and position in a collision experiment. But it can also help eliminate
sources of error by acquiring data under identical operating conditions. Well, to
demonstrate this capability, I'm going to do a simple experiment with a couple of
hand dynamometers. I'm going to hit my right hand against my left hand to see
which hand is stronger, and before I do that I'm going to disconnect my previous
experiment and connect the dynamometers to Analog Channel 1 and Analog Channel 2.
Now, over on my iPad in Graphical Analysis, I'm going to start collecting
data, and it looks like my right hand is connected to the red trace and my left
hand is connected to the blue trace. Now, I'm going to grip them both at the same
time as hard as I can to see which hand is stronger. That should be enough. Well, it
looks like my right hand won this time. If I select the data in this region, I can
show some statistics if I want to look at it in a little bit more detail and it also
shows that I was losing my grip strength the longer I held on to the sensors. So I
might want to turn on a linear curve fit and look at that slope in a little bit
more detail. Now, another great feature of LabQuest Stream is its ability to collect
data using fast sample rates. Investigating sound waves is an easy way
to demonstrate this, so I'll use a microphone to take a look at the tone
generated by this tuning fork. Now to get started, I'm going to disconnect my
dynamometers and plug in my microphone to Analog Channel 1.
Well, back on my iPad,
Graphical Analysis is all ready to go. All I have to do now is get my tuning fork
going. Well, here's how it sounds. Now, let's collect some data to see how it
looks. Well, you can see that we've got a really nice sign wave from that tone, and
if I go and look at the attributes of that plot, I can change the appearance to show
both points and lines. Now you can see all of the underlying data samples that
went into making that curve look so smooth. Well, the examples that I showed
highlighted LabQuest Stream's compatibility with iPads, but Stream can
also be used with Android devices, Chromebooks, and computers, and it supports both
Bluetooth and USB connectivity. For more information about LabQuest Stream and our
analysis software, please visit our website.