Re: Fw: Stair LEDs

["Ian Bird" <ian.bird@xxxxxxxxxxxxxx>]

A quick update - already

I spent some time thinking about this last night along with all the
other requirements already listed and I have two things to add.

1) The LED outputs will be voltage switching ones and not current
limited. This is because the resistors used in the current limiting
version are dependent on the LED and since I have no control over
what may be hung off these this is a risk not worth taking. Also, if
using commercial LEDs they may have the current limiting resistors
hidden in the 'string' somewhere and hence in the wrong place.

2) For my own application PWM is a really nice thing to have. To
this end I am modifying the design to incorporate a Maxim chip to
help with this. Samples ordered today and the programming gets more
complicated but the end result should be rather sweet.
The down side of this is the number of outputs goes to 16 but that's
life.

We shall see

Ian


--- In ukha_d@xxxxxxx, Gareth Cook <g@...> wrote:
>
> Exactly that :-)
>
>  Gareth Cook
>  Tools and Process Architect
>  IBM SWG Sales - Lotus Park, Staines, TW18 3AG
>  Office: +44 (0)1784 445166 - Mobile: +44 (0)7980 445166
>  AIM Chat : TheBoyG - MSN Chat : chat@...
>  email: g@xxxxxxx
>
>
> ----- Forwarded by Gareth Cook/UK/IBM on 17/03/2006 20:28 -----
>
> Discussion
> Main Topic
>
> ukha_d@xxxxxxx
> Today 20:24
>
> .
> Subject:
> .
> Re: Fw: [ukha_d] Stair LEDs
> .
> Category:
>
>
>
> Andy,
>
> There's a couple of videos on this site - I guess this is the sort
of
> thing Gareth & Ian are aiming for :-)
>
> http://home.cc.umanitoba.ca/~umparekh/stair_lights.html
>
> Cheers,
>
> Tim.