Entries from December 2006

• 1/2 C. Mayonnaise
• 1/3 C. White Vinegar
• 1 tsp. Vegetable Oil
• 2 Tbsp. Corn Syrup
• 2 Tbsp. Parmesan Cheese
• 2 Tbsp. Romano Cheese
• 1/4 tsp. Garlic Salt – or one clove garlic minced
• 1/2 tsp. Italian Seasoning
• 1/2 tsp. Parsley Flakes
• 1 Tbsp. Lemon Juice

From: http://www.copykat.com/component/option,com_rapidrecipe/Itemid,28/page,viewrecipe/recipe_id,851/

A provocative story over at MSNBC on “Babies with made-to-order defects” could make an interesting discussion for my ET class.

The tiny pager motors (VPM2 from Solarbotics) work great with the USB-1024HLS. I can drive them with the 15mA source capacity of the USB-1024HLS. Using duty-cycle modulation I can control the strength of the vibration. The 4-wire cable I used for each set of 3 is too stiff allowing vibration to couple from one to the next. I’m going to switch to long flexible pairs stripped from a flat cable. That should allow more freedom in placement and less coupling.

I bought a USB-1024HLS from Measurement Computing for an experiment with tiny pager motors as a cheap Braille display. For $149 you get a tiny brick with screw terminals. It works great. Their library is easy to use from Python using ctypes. I’m guessing USB timing limits it to 125 updates per second. I’ve got it blinking LEDs while I’m waiting on the pager motors to arrive.

Alex says the Brew development envrionment for Qualcomm phones is free. Perhaps we could do the Morse-code text messaging for deaf-blind people with that.

Great article by Fiona Morgan in the Independent Weekly. Lots of good ideas about open source and assistive technology.

http://www.freestandards.org/en/Accessibility/IAccessible2

From the IBM release: IAccessible2 is a new accessibility API which complements Microsoft’s earlier work on MSAA. This API fills critical accessibility API gaps in the MSAA offering. IAccessible2 was created out of necessity to produce a usable and accessible OpenDocument Format (ODF) based office suite for the Commonwealth of Massachusetts. IAccessible2 is an engineered accessibility interface allowing application developers to leverage their investment in MSAA while also providing an Assistive Technology (AT) access to rich document applications such as the IBM Workplace productivity editors and web browsers such as Firefox. The additional function includes support for rich text, tables, spreadsheets, Web 2.0 applications, and other large mainstream applications.

http://www.naturalpoint.com/optitrack/

OptiTrack is your complete optical tracking solution. From the camera to the software interface, it is everything you need to develop your own tracking applications! OptiTrack offers unique flexibility with its simple USB camera interface and powerful software API, a sample tracking application is included to have your system running right out of the box. Whether you need a single camera system, or want to have a room full, OptiTrack is the motion capture solution you need.

I’ve made the claim that we can drive a small speaker at a low frequency and feel it vibrating.

I’ve tried one set of Sony earbuds using my laptop to drive them and can’t feel it at all. My laptop audio seems to have VERY poor low frequency response and these earbuds are really tiny. Perhaps a bigger on the ear type headphone will work better?

Kurtis revealed the secret. You have to drive the headphone with 2 tones spaced close together. They have little frequency response down low but a beat between (say) 200Hz and 240Hz tones is small but I can feel it.

For $25 we can buy a little USB device that has 6 audio outputs. They intend them as front/back, left/right, and center/bass; this is called 5.1 audio. They provide three standard 3.5mm headphone jacks for plugging in the speakers.

Suppose instead we plugged in 3 cheap pairs of headphones giving us 6 speakers. I know we can drive 6 independent channels of audio out to the speakers at the same time. If we can make the sound loud enough a user should be able to feel the tiny headphone speaker vibrating with their finger. We could arrange the 6 speakers like the keys on a Braille embosser. You “feel” the dots with the same fingers you would use to press the keys. Or we could arrange them like a Braille cell if desired.
By playing low-frequency sounds on the 6 speakers we can make the vibrate. So to display a letter we play sounds to the appropriate dots. Only those speakers will vibrate.

A super cheap commodity Braille display you can assemble from parts easily bought anywhere…