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Re: RGB LED display

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  • Kerim F
    ... Hi Sanmeet, Sorry for being confused, and with your 16x16 RGB LED matrix we both know that there is no place for the static-mode drive. Since I have to
    Message 1 of 36 , Jul 1, 2010
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      --- In Electronics_101@yahoogroups.com, Sanmeet H <sanmeeth@...> wrote:
      >
      > >Hi Dennis,
      >
      > >You are right. If our friend needs to drive a matrix display with common
      > >cathodes or anodes then static-mode (each pixel has its own output) cannot >be
      > >used.
      > >But once he told me:
      > >"I am not using pre fab LED matrix but making the LED PCBs myself."
      > >So he has the freedom to analyse different modes and choose the best one for
      > >his project.
      > >I usually work with MBI5026 "16-bit Constant Current LED Sink Driver" (its cost
      > >is relatively low since it is widely used). There are many other ICs >based on
      > >the same idea but perhaps with different number of outputs and LED functions.
      > >For instance the IC "STP16C596 or STP16CP596" is a >similar one in all repects
      > >but it gives a better cascading timing (clock vs data) in case too many drivers
      > >should be cascaded. MBI5026 may need a >non-iverting buffer IC (I use 74HC245
      > >because I have a lot in stock) after cascading many of them or for each
      > >seperate LED display (or module) >with in and out data connectors.
      > >In my last design I used 32 cascaded ICs of MBI5026 without any buffer (The PCB
      > >length is 80cm) and the first one is connected directly to the >MCU pins (4
      > >pins, clock/data/latch/enable) like AT89S8253 or SST89E58RD (the latter can
      > >alter both its internal data and codes within itself >known as In-Application
      > >Programming, IAP)
      > >
      >
      > >In case someone would be interested in the static-mode, we can go on for
      > >further details mainly in case of RGB and, when necessary, some files >could be
      > >uploaded as schematics and perhaps datasheets.
      >
      > >Kerim
      >
      > Some schematics and details will surely be welcome.
      >
      > As for me I had got Matrix type PCBs made and I would be using using TI IC
      > TLC5926. I will post schematics and details for other people interested in a
      > similar project. Also, that way, I can get the forum members invaluable
      > feedback.
      >
      > Currently I am working with a 16 x 16 RGB LED matrix. I will post schematic in
      > RGBMATRIX folder in files section.. I have also given fabrication order for16 X
      > 16 RGB matrix in common anode configuration.
      >
      > Sanmeet

      Hi Sanmeet,

      Sorry for being confused, and with your 16x16 RGB LED matrix we both know that there is no place for the static-mode drive.

      Since I have to design things for sale, maximum brightness, maximum LED working time, simplest circuit configuration, simplest main controller in terms of speed and ICs count (could be reduced to just 1 IC, the MCU) and lowest overall cost have to be considered all. But this doesn't mean that scan mode is not better in many applications I don't work for.

      But since I stopped working with scan mode since a very long time, I think I have missed to know many new solutions made in this field. On the other hand, all the modules I produce (in China, as you may have already guessed) are now based on the static-mode so that I can minimize my work in updating the MCU software (firmware) which can drive the LEDs of the many sign models I build.

      In any case and as all members here do, when I have the answer of a question posted here, it will be always my pleasure to share it with you and others. And of course, when necessary I may ask for help too.

      Kerim
    • Kerim F
      ... Hi Sanmeet, Sorry for being confused, and with your 16x16 RGB LED matrix we both know that there is no place for the static-mode drive. Since I have to
      Message 36 of 36 , Jul 1, 2010
      • 0 Attachment
        --- In Electronics_101@yahoogroups.com, Sanmeet H <sanmeeth@...> wrote:
        >
        > >Hi Dennis,
        >
        > >You are right. If our friend needs to drive a matrix display with common
        > >cathodes or anodes then static-mode (each pixel has its own output) cannot >be
        > >used.
        > >But once he told me:
        > >"I am not using pre fab LED matrix but making the LED PCBs myself."
        > >So he has the freedom to analyse different modes and choose the best one for
        > >his project.
        > >I usually work with MBI5026 "16-bit Constant Current LED Sink Driver" (its cost
        > >is relatively low since it is widely used). There are many other ICs >based on
        > >the same idea but perhaps with different number of outputs and LED functions.
        > >For instance the IC "STP16C596 or STP16CP596" is a >similar one in all repects
        > >but it gives a better cascading timing (clock vs data) in case too many drivers
        > >should be cascaded. MBI5026 may need a >non-iverting buffer IC (I use 74HC245
        > >because I have a lot in stock) after cascading many of them or for each
        > >seperate LED display (or module) >with in and out data connectors.
        > >In my last design I used 32 cascaded ICs of MBI5026 without any buffer (The PCB
        > >length is 80cm) and the first one is connected directly to the >MCU pins (4
        > >pins, clock/data/latch/enable) like AT89S8253 or SST89E58RD (the latter can
        > >alter both its internal data and codes within itself >known as In-Application
        > >Programming, IAP)
        > >
        >
        > >In case someone would be interested in the static-mode, we can go on for
        > >further details mainly in case of RGB and, when necessary, some files >could be
        > >uploaded as schematics and perhaps datasheets.
        >
        > >Kerim
        >
        > Some schematics and details will surely be welcome.
        >
        > As for me I had got Matrix type PCBs made and I would be using using TI IC
        > TLC5926. I will post schematics and details for other people interested in a
        > similar project. Also, that way, I can get the forum members invaluable
        > feedback.
        >
        > Currently I am working with a 16 x 16 RGB LED matrix. I will post schematic in
        > RGBMATRIX folder in files section.. I have also given fabrication order for16 X
        > 16 RGB matrix in common anode configuration.
        >
        > Sanmeet

        Hi Sanmeet,

        Sorry for being confused, and with your 16x16 RGB LED matrix we both know that there is no place for the static-mode drive.

        Since I have to design things for sale, maximum brightness, maximum LED working time, simplest circuit configuration, simplest main controller in terms of speed and ICs count (could be reduced to just 1 IC, the MCU) and lowest overall cost have to be considered all. But this doesn't mean that scan mode is not better in many applications I don't work for.

        But since I stopped working with scan mode since a very long time, I think I have missed to know many new solutions made in this field. On the other hand, all the modules I produce (in China, as you may have already guessed) are now based on the static-mode so that I can minimize my work in updating the MCU software (firmware) which can drive the LEDs of the many sign models I build.

        In any case and as all members here do, when I have the answer of a question posted here, it will be always my pleasure to share it with you and others. And of course, when necessary I may ask for help too.

        Kerim
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