A $10 (CAD) hearing aid…

But its closest equivalent is  sold at much more.  Wish us best at the Ken Spencer competition. In the meantime, the CAD, C-code, assembly code, and a few more DIY instructions should go up soon.  Hopefully such a simple device goes far. On the plus side, this implementation also includes a playback feature, so that the most recent ‘x’ seconds of audio are always recorded, and are always available for playback. Very useful when a hearing condition interferes with listening to the radio, TV, a conference, or more.

WiiMote Multi-Touch Whiteboard

Inspired by the original project at http://johnnylee.net/projects/wii/ , I decided to try this out for myself. The results were great. For a little under $5 worth of parts from Digikey, I was able to implement a few whiteboard pointers. Although the circuit is really simple (a current limiting resistor should really be put in place) some people may want to know that the pointer actually works prior to testing it on the whiteboard, wondering why nothing’s happening when the polarity of the LED is incorrect. The human eye can’t see the IR light emitted by these DIY pointers, but a digital camera can. Simply get any old digital camera (I used the one built into my LG phone) and just aim it at your IR LED in “preview” or “video” mode. The IR LED will shine brightly on the phone’s screen when the LED is active.

IR LED - Inactive, as viewed on my phone's camera

IR LED - Inactive, as viewed on my phone's camera

IR LED - Active, as viewed through my phone's camera

IR LED - Active, as viewed through my phone's camera

One may get even better results with a more specific LED, such as those listed here: http://wiicanetouchgraphic.blogspot.com/2009/03/wii-remote-ir-sensitivity.html . LED #4 seems to be the ideal choice, according to the author.

Also, with the use of some Silicone Singles (C), courtesy of WestOne (www.westone.com) I was able to make some custom-fitted finger pointers with the IR LED built right into them. These are little packages of a silicone putty (two types actually), that you can roll together in your hands like dough. Once you’ve combined them, you have about 5 minutes to form your shape, and it then hardens permanently. Fantastic stuff! Now you just need a Darth Vader or Iron Man novelty glove, 4 IR LEDs (a single WiiMote can track up to 4 IR sources at once), and you have one spiffy looking multi-touch enabled input device.

WiiMote, IR Pen, and IR Finger Pointer

WiiMote, IR Pen, and IR Finger Pointer

Next, using the WiiMote whiteboard software provided at johnnylee.net, along with a demo version of SmoothBoard, I was able to really get the ball rolling with some fun demo applications.

I’m considering building a simple multi-touch game for this in future, once the semester’s up. I have enough on my plate now with work, school, a project for BC Cancer Agency, and other independent work as part of an MRI analysis project.

I’ve tested the WiiMote successfully with the Asus Bluetooth Dongle (Asus BTD-21) and the builtin BroadCom one built into my Dell Mini 9. In the case of the BroadCom bluetooth radio (using the WIDCOMM drivers), some people have hit a snag when trying to pair the devices, stating that they have to enter a passkey, and that no option to “skip” or not enter a passkey at all presents itself. Simply update the WIDCOMM drivers to the latest version from BroadCom and it should work without any issues at all).

Automated SPA Analysis

Well, time for another project to chew up whatever free time I have lately. This was a fun h/w interfacing project. Another GUI and DAQ setup really, this allows for rapid measurement and data acquisition though an HP4155C semiconductor parameter analyzer (SPA). The GUI is straightforward, and built to run on Linux (Slackware of course). This little tool has made automating and cataloguing measurements of diodes and dielectrics even quicker than ever before.