Dual Color 7-seg LED display ??

don wibbled on Friday 05 February 2010 15:21

Kingbright do some:

(Red, Green - should do what you want assuming the colour mixing is OK).

Thanks for that.

The application is a programmable timer.

The display would be yellow to set and green for run (count down).

I thought of flashing for set and static for run, but the two color option seems easier to understand.

don

Unless you're colorblind.

Hmmm, good point.

don

So flash _and_ use color. More clues are better than fewer.

Jon

On a sunny day (Fri, 05 Feb 2010 13:10:21 -0800) it happened Jon Kirwan wrote in :

Use an alphanum display with text set and run ...

Since we are on the subject, I think sound would help. Needs a speaker. After all, blind people need programmable timers, too. ;)

Jon

Is there a type of colorblindness that makes it difficult to distinguish between green and yellow? I thought the main kinds were blue-yellow and red-green...

Nevermind, green is of course blue and yellow...

Yes, achromatopsia. Though *considerably* less common than R-G.

Note that color blindness may also be a temporary condition brought on my illness (migraine, etc.) as well as "acquired" with age. It can also affect only *portions* of your field of vision.

On Feb 5, 4:56=A0pm, Bitrex wrote: > DJ Delorie wrote: > > don writes: > >> I thought of flashing for set and static for run, but the two color > >> option seems easier to understand. >

My 13 year old boy has exactly that problem with a Nintendo DS that uses a red/green LED for battery state.

G=B2

I was looking at the chart here:

that shows what a rainbow looks like to people with various forms of color blindness. It seems that if one were to make the data in a two-color display either blue and orange or indigo and green, one would cover all the bases and have a combination that would be easily distinguished by those with various types of color blindness, except of course the kind you mention that is a complete lack of color perception. I remember reading that some military radar screens used blue and orange as a color combination, but I think that was because some study indicated it was the color combination easiest to stare at for long periods of time...

Even with particular types of color blindness (red-green, for example), you can chose the colors such that a color blind person can perceive the *difference* -- though they may not be able to tell which color is which.

E.g., ages ago, when my Dad applied for his (initial) driver's license, the examiner showed him a stoplight and asked the meaning of each (lit) "indicator". At one point, he rotated the "display" sideways instead of the familiar vertical orientation. Not knowing which end was the "top", my father couldn't tell "stop" from "go".

Or, perhaps the phosphors had the longest persistence?

Hey, you better believe it!

SWMBO has this nice calculator, a Sharp that hasn't been made in years, that both speaks the numbers when she calculates, it also has a timer, alarm and CALENDAR! I dread the day that this thing finally give up the ghost, because you can't buy anything like it anymore...

Oh yeah, it also has a nifty timer on it. You set the time (minutes only) and every five minutes it tells you how much time is left, then at one minute it warns you, and when your time is up, it tells you "Your time is up!" and plays camptown races...

Charlie

On a sunny day (Fri, 05 Feb 2010 22:21:49 -0500) it happened Bitrex wrote in :

Hey, that must have been subconsciously what I selected for colors in my newsreader: ftp://panteltje.com/pub/NewsFleX-colors.gif

color

would=20

of=20

perception.=20

It was actually an easy to make combination with non-color oriented = visual=20 properties. The P7 phosphor allowed the operator to clearly distinguish=20 between sweep traces and return images. They were still in use for the=20 master display for SPS-48 and SPS-51 3D air search radars in the early =

All the comments in this thread were interesting and useful.

But, I have not found any dual-color 7-seg LED displays.

Has anyone run across a display like this, with any two colors ??

don

don wibbled on Thursday 11 February 2010 03:07

Eh? I gave you a reference to a Kingbright part, R/G and therefore yellow supported.

Yes, Thanks, I saw that.

At 1.5" tall, its an over kill for the from panel.

I would hope others have seen more out in the wild.

don