Author Topic: Side-Mounted LED - a whole new approach  (Read 7432 times)

Offline micbridge

  • *
  • Posts: 28
  • Karma: +1/-0
    • View Profile
on: May 11, 2008, 05:36:03 AM
Hey gang. I've been working on a new pen concept that would fix the traditional problems with the original IR LED design: forward facing LED, IR wavelength not optimal, one LED not powerful or large enough. I found a different kind of LED light at Mouser.com that is smaller and flatter then your traditional LED. (see mouser link below) You can fit three of these across a dime and when you lay them on the table the light would shine up towards you not to the side. Their wavelength is 870nm which I understand from this forum is right where the wiimote is most sensitive to IR light. The old Vishay TSAL6400's are 950nm which work but I wanted every advantage when trying to get my wiimote to pick up the IR light.

So I set out to get these and put them on a previously made pen. I used the online LED calculator and got my new resistors (10 ohm 1/8 watt). The little LEDs were difficult to solder because of their size, but the end result was brilliant. Too bad I'll have to wait till work tomorrow to try them out. I expect great things however because if the old style pen kinda worked, this pen has got to give the wiimote a definite light source to follow.

I'll return and report how it performed, meanwhile please link to my Picasa page to view photos and specifics on the pen and the new diodes. Look at the second half of the photos to see the new diodes.

One last thing. I planned to make two pens: one large format pen with four leds for presentation use with a projector, the other will be a very small slimline pen for use at my desktop monitor using only one of these diodes for Photoshop work.



http://www.mouser.com/Search/ProductDetail.aspx?qs=oNDV51lhjEMyspNOxDDOcA%3d%3d
http://picasaweb.google.com/Micbridge/WiimoteWhiteboardProject


« Last Edit: May 11, 2008, 06:01:27 AM by micbridge »



Offline micbridge

  • *
  • Posts: 28
  • Karma: +1/-0
    • View Profile
Reply #1 on: May 11, 2008, 05:43:57 AM
Here are a few of images of the pen.



Offline micbridge

  • *
  • Posts: 28
  • Karma: +1/-0
    • View Profile
Reply #2 on: May 12, 2008, 06:22:08 PM
I was able to test the pen out at work today. The side-mounted LED works great. The wiimote picked it up easily and I didn't have to turn the pen in screwy angles.



Offline Descalzo

  • *
  • Posts: 25
  • Karma: +0/-0
    • View Profile
Reply #3 on: May 13, 2008, 01:24:04 PM
How does this affect accuracy?  I would think that you would have a much larger blob.



Offline micbridge

  • *
  • Posts: 28
  • Karma: +1/-0
    • View Profile
Reply #4 on: May 13, 2008, 06:46:42 PM
I tested this pen out only on my 15" LCD monitor at my desk and it was surprisingly accurate. I found I had no problem clicking on the windows start menu and pick programs out of the small icon list. I could close windows in the far right on the first click, and grab the slider bar to scroll the screen. I actually had planned on making this the larger of two pens. The larger one I'd use with a projector on business trips. I will make a small one, probably out of a laser pointer, with just one led facing left. I think this smaller pen will further enhance the accuracy. I'll use it to paint on architectural renderings in Photoshop at my desk. The lighter setup of the laser pointer sized pen would also be easier to hold up for a long time.



Offline KDReeves

  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
    • BattlefieldTeachers.com
Reply #5 on: May 13, 2008, 08:19:01 PM
This is a very interesting approach. After the next couple of builds I might have to try one of these! I suppose it would be nice to have one of these in my "array" to offer. I think the optimal orientation may depend on the user's natural tendencies.

One of my primary priorities when I go to deploy this at my high school will be to demonstrate transparency between existing deployments (we use both SmartBoards and Mimios) and this technology. If I can show that the only difference in use is that you have to press the button, it'll sell itself. Having a variety of pen options (and telling a teacher I'll build them their very own pen, customized just for him/her) will be a big selling point and this is another one in the array!

Very cool.

Keith David Reeves, B.Mus., M.Ed.
Instructional Technologist
Battlefield High School
Haymarket, Virginia


Offline micbridge

  • *
  • Posts: 28
  • Karma: +1/-0
    • View Profile
Reply #6 on: June 21, 2008, 09:28:51 AM
I finally had a chance to use this pen in a real work presentation, well three presentations actually. I used it in conjuction with a powerpoint presentation and it's internal pen function. I used this pen to mark up floor plan changes requested by the clients in real time. It worked great. In fact, my Project manager originally thought I had used a red marker to mark on the client's wall. The look on his face was classic. It took forwarding to the next powerpoint slide to make him realize it was a digital markup. I also used my magnetic ceiling mount for the Wiimote.

I'm happy that after all this time I had a chance to use this stuff for a practical application.