Sygnet handsfree design flaws, part 2: Control overloading

Sygnet Handsfree with stickersBack to my Sygnet Bluetooth Handsfree Carkit model BTS600. We saw its problem with cloaking the controls and indicator lamps… but on top of that, the people at Sygnet played a trick that is becoming very common in this digital era: they overloaded the controls and the lamps.

I use Overloaded in the Object Oriented Programming sense: the use of one operator or function name to perform several different functions depending on context.

The Sygnet device has three operating buttons and more than a dozen actions; so each button can do many different things. For example, the “-” button rejects a call if pressed for 3 seconds while the phone is ringing; it initiates voice recognition dialing if pressed for 3 seconds when the phone isn’t ringing; it cancels the voice recognition if pressed until a beep is heard; it cancels bluetooth device recognition if pressed for 6 seconds; it reduces audio volume; it mutes/unmutes a call when pressed concurrently with the “+” button; and it starts a conference call if pressed for 3 seconds while one call is active and another waiting. The other buttons likewise do a great many things; it’s so complicated that I carry the instructions in the glove compartment at all times! Needless to say, the captions on the device merely identify the buttons, not their functions.

The two indicator lamps, meanwhile, are similarly overused: The blue lamp blinks 3 times every 2 seconds to indicate an active Bluetooth link; it blinks rapidly together with the red lamp when the device recognizes the cellphone; it blinks every 2 seconds when bluetooth is inactive; it stays lit with the red lamp during charging, and without it when charging is completed. So now you need a stopwatch to figure out what it means…

To illustrate how excellent this human engineering is, consider its application in a ballistic missile situation: “Hey, Joe, does two blue blinks followed by a long beep mean a 3 second push on button D launches the missiles unless you first tap on button A, or does it mean the Mr. Coffee needs maintenance?”

So, what can we do about this? Well, by now you know my style. At least I could make the cloaked buttons eminently visible…

Sygnet Handsfree with stickers

0 Responses to “Sygnet handsfree design flaws, part 2: Control overloading”

  1. No Comments

Leave a Reply