Commodity Example

Let’s take a look at the extractor hood fan above the stove. From the user’s perspective, the user can push the two-options-‘button’ (I don’t know the exact English name for this kind of button) to the left to turn on the fan to high speed. He can also push the button to the right to turn on the fan to low speed. If the button is neither pushed to the left or right (stays in the middle), the fan is off.

The switch is likely to be a SPDT switch, meaning that there are 1 pole and 2 throws. It is a diverter switch. It is not a momentary-contact switch because the button stays pushed to the left or right while the fan is on. NC/NO forms do not apply to this case because it is not a momentary-contact switch. It is a center-off position switch (has an additional ‘off’ position located between the two ‘on’ positions).

Voice input: use speech recognition technology to recognize what the user wants to type

Advantage:

• hands-free control, useful while driving

• if done right, can type very fast

• does not require a lot of attention while typing

Disadvantages:

• Hard to recognize accurately what the user said (due to accent, background noise, etc)

• It may take long time to type, if the voice is send back to the server from mobile device and let the server process the sound

http://www.apple.com/iphone/features/siri.html

Gesture input: use computer vision to understand users’ gesture

Example: Gmail Motion (http://www.youtube.com/watch?v=Bu927_ul_X0)

Someone made this real: http://www.youtube.com/watch?v=Lfso7_i9Ko8

Use a linear encoder.

The resolution depends on the precision with which the measurement is made. Usually, in a digital display, the least significant digit will fluctuate.