Do It Yourself Document Camera

A couple of weeks ago I wanted to share information with my class from a textbook that we don't use. I didn't want to photocopy and I thought why not try to use a document camera. Our school only has one document camera and given my organizational strategy, it was the night before I needed it. I hoped that the teachers who normally used the camera were not using it the next day but I started thinking about a plan B just in case. I thought if the document camera were in use I could set up a webcam and point it at the book and have the image appear on the screen. It turns out that the document camera was not in use so I didn't need to worry about plan B.

I still wanted to pursue plan B in case I ever needed a document camera again. So a week ago I took a webcam and an old lamp and put them together to form an inexpensive document camera.

Here's a rundown of how I did it.

I started with a lamp that was adjustable so that positioning could be flexible.

From there remove the nut holding in the guts of the light so that you can remove them, as shown in the picture below.  You'll have to detach the socket from the wire. This can be done by loosening the two screws holding the wires in place.

 Trim the wires. I didn't remove the wire entirely since I wanted to use it to tie the camera in place.

Now that the wires are loose you need to ensure that the lamp can't be plugged in, otherwise you could be in for a bit of a shock. You can either cut the wire somewhere, or snip off the prongs. I was unsure as to how long to make the wire so I cut off the prongs. Failure to prevent the lamp from being plugged in could result in serious harm or death. Consider the safety of those around you.

Use a rotary tool to cut out a hole large enough to fit the webcam cable through. Put on some safety goggles while doing this. It's not worth losing an eye over a webcam. You may want to file off any rough edges since the cable for the webcam will be passing through here.

Pass the cable for the webcam through the hole and use the lamp wires to tie the camera on. Pull everything nice and tight so that it doesn't move around. I found that the wire for my lamp held everything in place. You may have to tie the wire to the stand if the camera moves around too much.  I thought about finding a way to permanently attach the camera into the lamp, but I'm not finding it necessary. Perhaps there's some way to glue plastic to metal? If you have any good ideas feel free to share them.

Once the camera was setup it was a question of finding software that would allow me to display the video. The software that comes with the webcam can work but it often won't allow you to show the video full screen. So here are a couple of options. On a Mac try the QuickTime Player (File->New Movie Recoding then make it full screen). I tried iChat first but soon realized that iChat always gives a mirror image. Not so good for text. For Windows try FSCamView. It's a very simple program that takes the input from your camera and displays it using the entire screen. The quality of your video may very depending on the quality of your camera. An HD webcam may be worth the extra expense ($50 vs. $25).

Lighting may also be an issue. If so you may wish to consider an LED light. You can get some that plug into the USB port of your computer like this one or this one, or battery operated units, or even a solar powered light.

As I was searching for software solutions I came across a post where someone used an overhead projector (OHP) as the stand. I'll have to dig around the school for an old OHP that doesn't work and try it out. On second thought, I bet nobody would notice if I used the OHP that collects dust in my room.

I really enjoyed this little DIY project. The most exciting part for me was saving a ton of money by doing a little bit of work. It may finally be time to build the wiimote interactive white board.

Open Doors vs. Closed Doors

The other day I had the opportunity to work on a project with a colleague. We spent the morning working in the library at the school. We finished up the project a couple of minutes before lunch and as I headed back to my office I noticed that every classroom door I passed was closed. There was nothing special happening at the school that day, no particular reason the doors seemed to be closed. As I noticed this I wondered if most teachers in the school regularly teach with their doors closed. Then I began to wonder what, if anything, teaching with your door open or closed says about you as teacher? I starting to think this could be a could statistics project. Have students wander the halls daily, tallying the number of open doors vs. closed doors then have students perform so statistical analysis to see if there are any types of relationships between when doors are open versus when they are closed.

I personally teach with my door open. I do it for two reasons. The first is that I enjoy the flow of fresh air that results in having the door open. When I teach with my door closed it feels as though the air in the room becomes stale. I'm not sure if there is in fact any difference in the air quality but that's how it feels.

The second reason I teach with my door open is that I want my class to be an inviting place. I want teachers, administrators and even students to feel as though they can stop in at any time. I want teachers and administrators to stop by to see what we're up to or to share an interesting story or lesson. I want students to feel that they can stop by for extra help or to share their math struggles and successes. It's exciting when a senior student comes by for extra help or wants to share how well they did on a test or assignment when I'm teaching a junior class.

Do you, generally, teach with your door open or closed? How come?

Angry Parabolas

As a way of connecting quadratic functions to something my students would  be familiar with I decided that we should play a game. Not just any game. I wanted to focus on one of the most popular games available for mobile devices. So I hooked my phone up to a projector and fired up Angry Birds. Most, if not all, of my students were familiar with the game and couldn't believe that we were playing it in math. I heard comments such as "Are we really going to play this?", "Is this a joke?", "What's the catch?", "You're going to link this to math aren't you?".  If nothing else they were interested in what the link to math was.

I had a couple of students come up and try the game. Once they had a chance to play I gave it a try and fired the bird high into the air so that it made a beautiful arch. I didn't hit a single obstacle and my students thought I was completely incompetent at the game. They sincerely offered suggestions about how I could improve. Eventually they realized that I had no intentions of hitting anything. I explained that the interesting part about the game is that it leaves behind a nice trail showing where the bird had been.

I took a screen shot and fired it up on the computer. We labelled the parabola and discussed some terminology. I didn't feel the need to write out any definitions. They seemed to get the ideas. It was funny to hear students helping each other by referring to the game in their explanations.

The game provided a good introduction to the unit and I wondered how I could take it further. My first thought was how cool would it be to have students write a simplified version of the game? They would learn the math, a whole ton of problem solving and some programming.  I wasn't prepared to do this since I thought it would take up too much time. I may however consider using Sam Shah's technique of modifying a program in the future. Perhaps I could write the program and they could modify it so that it worked properly.

My second thought was to have students determine the equation that modelled the path of the bird. I created a Geogebra file with the image as the background and a grid laid on top of the image. I had students determine the equation at their seats first, then I had a student come up to board and move the sliders around to reveal the equation.You can find a link to the Geogebra file here.

I'd like to find a good way of determining the equation of the function that will allow the bird to hit a certain location and use this information to improve game play. I can see some technical challenges here. I'll have to think about this for next time.


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