The Very Spring and Root

An engineer's adventures in education (and other musings).

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Use Your Phone as a Streaming Document Camera

As a science teacher in an increasingly technology-driven world, I have found document cameras to be very useful for a number of purposes. A connection to the SMART Board or projector allows students an enhanced or alternative view of any class demonstrations, and I can also ask students to explain their written or solved work for the class with everyone following along on the screen.

Document cameras ain’t cheap though. The official SMART Document Camera runs about $800 (!), and even a generic webcam can run $40-50 or more depending on what you are looking for. For the budget-conscious (or budget-constrained) educator, these options can be beyond reach.

I was looking for a cheaper alternative and thought, wait a minute. I’ve got a camera right here on my Android phone already. Why not find a way to use that?

Here are the results from trying out two different apps.

Phone Stats

I have a smartphone, but its a pretty generic one. Go back to that bit about budget-constrained. Right.

LG Optimus V (Virgin Mobile), with Android 2.2 and a 3.2 MP camera.

IP Webcam

The Android app IP Webcam allows you to turn your phone into a little video stream server. You can adjust various settings (video resolution and quality, orientation, etc) and then stream to a local IP address. The stream URL can then be viewed via a media client like VLC or Quicktime, or directly through your browser’s native video player.

You can also have it fade the screen to blank to save battery (it doesn’t let you actually shut off the screen, since that seems to be linked to ramping down the processor as well).

The partial screen capture (scaled to 60%) below shows the feed in Firefox with the phone held about a foot away from the document under a normal table lamp in otherwise dim lighting conditions.


Here is another screen shot, also holding the phone about a foot away, that shows resolution of handwritten text and diagrams for demonstrating problems.


Five minutes of WiFi broadcast at 640×480 (3MP), full quality, and phone screen on fade-mode resulted in a battery drain of only 2%, which is pretty good. If the display were left on, I’m sure this would be much higher. I also have a very weak processor and no autofocus, both of which would take more power if your phone has them. However, I see no reason why you couldn’t just plug in your phone while streaming if you needed it.

As you can see from the browser control interface below, the app supports many ways to access the stream (including Skype integration), and also allows screen-capture photos and audio streaming as well (I did not test the bitrate).


I was not able to get the stream to work over 3G, since the IP address that the cell tower assigns to my phone seems to be LAN only. It would be an interesting experiment to see if another Virgin Mobile customer standing next to me (and hence presumably connected to the same tower) would be able to see my stream on his/her phone!


The DroidCam app works through either WiFi or USB, and hence requires a client install on the viewing laptop. The pro version claims to also add 3G and bluetooth connectivity, as well as remote control for flash, zoom, autofocus, etc.

The app performs poorly compared to IP Webcam. The video quality is noticeably lower for the same resolution, and the phone experiences a higher battery load (3.5% in five minutes, same conditions). Also, the option to display the stream through the browser via an http connection is disabled unless you buy the pro version, so you must use their client software to view the stream.

The advantage over IP Webcam presumably is that you can use USB mode to stream directly to a client computer even when you don’t have WiFi available. However, I was not able to get the USB mode to work properly on my Windows 7 netbook with minor fiddling. I would assume that if one could get the USB mode working, battery drain would be significantly less, since the phone should be able to draw on the USB power bus while connected.


Of the two apps tried above, I would go with IP Webcam for sure. I tried the app on WiFi mode while connected to the BPS network and it worked fine (the app uses the standard http web port 8080, which means that its highly unlikely anyone will block the port). There seems to be no need to try very hard to get the USB on DroidCam to work, especially considering that the quality is lower.

At only 3MP, fine detail is going to be lost, but for visual enhancement it seems like this should work fine! Also, if you have a higher resolution phone camera than me, obviously your phone will deliver a higher resolution image.

Bonus: the web streaming means that any student with the right IP address (which you can give them) on the local net can actually get the stream directly on their smartphones or laptops anywhere in the school. I don’t think even the $800 SMART Document Camera will do that, and this app is FREE!