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Wow, I thought this list was dead.
Hmmm. You're missing two key bits of information :
1) Do you want to individually control each LED's brightness?
2) How often do you wish to change the brightness?
If you are attempting to make a television like display its a lot harder
than if you're making simply a LED sign.
--Chuck
At 11:37 AM 2/29/2004, Claudia Bernett wrote:
> hi.
>
> i'm working in a project in which i'll need to control the brightness of about
> 700 leds. i've just begun to research solutions - and i'm not sure the hb is
> the right microcontroller for the job, but i thought perhaps an hb user on
> this
> list would have some relevant experience and could perhaps point me in the
> direction of the right hardware/software combination. it seems as though i'll
> need multiple microcontrollers, and additional hardware to manage the
> control of
> a large numbers of leds.
>
> the MAX6954 4-Wire Interfaced, 2.7V to 5.5V LED Display Driver with I/O
> Expander
> and Key Scan made by maxim-ic was suggested as a possibility - if anyone is
> familiar with it.
>
> http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3410
>
> separate but related, i'll need the software running on the mc to be able to
> return the current time, down to seconds. i know system time is available on
> the hb, but gets reset everytime the device is rebooted. so - if there
> are any
> suggestions regarding a solution for this piece as well it would be much
> appreciated.
>
> thanks in advance,
> claudia
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hi.
i'm working in a project in which i'll need to control the brightness of about
700 leds. i've just begun to research solutions - and i'm not sure the hb is
the right microcontroller for the job, but i thought perhaps an hb user on this
list would have some relevant experience and could perhaps point me in the
direction of the right hardware/software combination. it seems as though i'll
need multiple microcontrollers, and additional hardware to manage the control of
a large numbers of leds.
the MAX6954 4-Wire Interfaced, 2.7V to 5.5V LED Display Driver with I/O Expander
and Key Scan made by maxim-ic was suggested as a possibility - if anyone is
familiar with it.
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3410
separate but related, i'll need the software running on the mc to be able to
return the current time, down to seconds. i know system time is available on
the hb, but gets reset everytime the device is rebooted. so - if there are any
suggestions regarding a solution for this piece as well it would be much
appreciated.
thanks in advance,
claudia
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Hello,
we are using Lego reflectance sensors for an experiment and the HB is
showing a rather strange behavior. If we plug a single sensor in the
expansion board, it works fine, but when two of them are connected, then
none of them work. Even more, if the single sensor reading is 200 decreases over
185 when the second one is connected, without any change in sensor position. We
tried the 4 lego sensor inputs and nothing changes. We are
sure that it is not a sensor problem, but what is it then? any idea?
thanks!
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Hello,
when I switch the HB on, first both -- batt and pow -- lights are on for a
second and inmediatelly, both become off again. The U13 voltage regulator
gets very hot in few seconds. I've changed that unit but there is no change in
the board's behavior. I think the board is shortcircuited some where, but
where?
thanks!
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