Measure. Analyze. Learn.
Hi, I'm Dave Vernier, and I'm here to show you how to use
the Digital Control Unit, the DCU, with Logger Pro.
Now, the DCU has been around for a long time.
But, up until now, it's been used mostly by,
people who are programmers, and writing programs in
languages like labView, to do projects.
And, for example, in this book we have called,
"Engineering Projects with Vernier",
we have a lot of projects using the DCU.
But recently, we added some functionality to
Logger Pro such that, you can actually control the DCU,
and do lots of interesting projects, without any programming,
just setting up things in Logger Pro.
And, I'd like to show you an example.
Here, I have a DCU connected to a LabQuest Mini.
Now, the DCU has its own power supply.
You can use either a LabQuest power supply,
or a Lab Pro power supply.
You connect whatever devices
you're going to control to the DCU.
Here, in this case, I have a LED, and a buzzer.
And then, in this case, I have a motion detector
also connected to the same LabQuest Mini.
Now, I've got a Logger Pro Running here and
the motion detector is plotting distance; position versus time.
If I want to control the DCU, I click on the setup sensors option.
And then, I click on the "Digital Control Unit"
in the control box there.
And, there's a pull down, for "Digital Outputů".
In that, I can set the activation of the line.
So, the statement I'm going to use here is,
"Activate Line 1" - "If" - "Position" - "Is" - "less than [<]" -
I'll say, "half meter [0.5]"
So, it's sort of like building a sentence there.
And, let's just see what this does.
I'll close the dialog.
And, I'll hit the collect button.
And, you'll see what you'd expect.
That is, the motion detector is plotting distance.
If I move closer [beeeeeep] than a half meter [beeeep]
our LED goes on.
So, with the addition of the motion detector and the DCU,
we're able to make a simple alarm system,
without much effort at all.
There are lots of other possibilities with this.
For example, when I was in there configuring the activation,
I could've set it up so that the buzzer and LED
go on after a certain time interval.
Say, "10 minutes into an experiment", where you want to
remember to add some chemicals if you're doing something.
Or, to remind you to turn off something when
it's getting tired, or something like that.
So, there's lots of possibilities.
Also, if you look at the dialog box, you'll see that
there's actually three lines you control; line 1, line 2, and line 3.
And, in each case you can do compound statements.
So, for example, I could have said,
"Turn on line 1 when the position is less than a half meter,
AND, the time is greater than 10 minutes."
So, you can do those kind of things.
And, I've got three lines to control.
So, I have some real possibilities here.
Now, to show that to you, and also to have some fun,
we're going to show you our Logger Pro controlled tea maker.
So, let's take a look at our tea maker.
First, we have a motor here,
which will raise and lower a tea bag,
above and into the cup there.
We have a Vernier Infrared Temperature Sensor here,
reading the temperature inside the cup.
We have a photogate here.
And on this side, of course, we have the DCU.
And then the DCU is connected over here
to the motor via this wire,
and also to a LED and buzzer arrangement,
just like we had in the earlier part of this video.
So, in terms of software, we're using Logger Pro.
And, if you look at this screen we spent quite a lot of time
setting up, kind of, a custom tea making file for Logger Pro.
We have instructions.
We have a photo showing how to connect the tea bag.
And we have user parameters which let you set the
brewing time of your tea, and the serving temperature
that you like your tea served at.
We have a graph, and we have a thermometer.
So, let's make some tea.
If I hit the collect button on Logger Pro;
tea bag is lowered,
and now I'm going to add some hot water,
you should see the temperature going up.
And now, we're into the brewing time.
Now, I set the brewing time for two minutes.
I want to make some fairly weak tea here,
because I'm trying to speed things up.
We're also going to drink it pretty hot,
also to speed things up.
But now, we'll see a graph happen,
but will show a slight cooling of the tea.
but also we're just waiting out the time for the two minutes.
Remember, in Logger Pro I can set a control to
turn on a line when the time is greater than a certain limit.
When we reach two minute end of the brewing time
the tea bag is lifted out.
And, we actually used the photogate as a way to mark
the right position for it to stop.
When the LED is blocked, we stop.
That's one of those combined statements.
We said, "When brewing time is done, AND,
photogate is blocked, STOP."
So, now we're going to go through a period where
we read the temperature and we watch until the
temperature reaches a proper serving temperature.
We started at about 70 degrees here, and Celsius that is.
And, most people don't want their tea that hot.
So, maybe about 60 degrees or so, that's what I set it for.
And, when that happens, we'll get the buzzer and LED going off,
indicating it's the proper time for our tea to be served.
[beeeeeeep]
So, the buzzer goes off, and the LED is on when the tea
is at the proper temperature.
And now, I think I'll have a sip.
Ahhh.
So, that's our Logger Pro tea maker.
We've had a lot of fun with it.
We think that the combination of the DCU and Logger Pro
allow some great projects for your students.
It's a great way to add STEM to your classroom,
because all of these have a little bit of engineering to them.
And, we think you'll have a good time with this.
For more information, check out: www.vernier.com.