led matrix 30x30, scan mode 1/3

[andrei0807]

I have led matrix of 30x30, scan mode 1/3. I am going to control this on Pi using this library. But it was not work correctly. How to set params for this led matrix. Please help me. Thanks.

[hzeller]

that is an unusual scan mode that I have not come across before; probably needs slight adjustments in the code. Can you take a picture of the connector on the matrix PCB including the labeling ? Do you have a datasheet ?

1/3 implies that we have essentially have in each half display 3 stripes of 5 led rows if it otherwise behaves as usual panels. Probably sufficient to just write another multiplex mapper.

[andrei0807]

Thanks for your response, I will send you datasheet now

[andrei0807]

Does it make sense? Is this enough? Can I use this library for this LED matrix?

[hzeller]

Yeah, this looks doable if it otherwise works with the library. If you connect it to the library, do you get any output (albeit garbled) when you run the demo ?

You essentially need to add a new multiplex mapper in lib/multiplex-mappers.cc. I am currently travelling (eventually hitting Chaos Communication Camp), so can't really help much right now.

[andrei0807]

Thanks for your response and sorry to disturb your rest. Should I add class like this?

[andrei0807]

@hzeller Can you explain about parameter's mean and function's login?

[hzeller]

See the header files for the corresponding class you implement. A Mjultiplex mapper is based on a PixelMapper who's parameters etc are described in the corresponding header in detal https://github.com/hzeller/rpi-rgb-led-matrix/blob/master/include/pixel-mapper.h

The Multiplex mapper is derived from that, and only adds one more method the EditColsRows() https://github.com/hzeller/rpi-rgb-led-matrix/blob/master/lib/multiplex-mappers-internal.h

.. there is already an implementation in MultiplexMapperBase, that implements that so you could instantiate that with 3 as parameter; Then the only function you need to implement is MapSinglePanel(), which takes the original x/y [0..29, 0..29] range and maps it to the new [0..149, 0..9] range. Something like this would be probably a good starting point:

class ThirdMultiplexMapper : public MultiplexMapperBase {
public:
  ThirdMultiplexMapper() : MultiplexMapperBase("Third", 3) {}

  void MapSinglePanel(...) const {
    // ... implementation according to your data-sheet
 }
};

Then register it in CreateMultiplexMapperList() and it should be available via the command-line flags.

[angelogoncalve]

https://github.com/hzeller/rpi-rgb-led-matrix/blob/master/lib/multiplex-mappers.cc

/*

• Here is where the registration happens.

• If you add an instance of the mapper here, it will automatically be

• made available in the --led-multiplexing commandline option.

  */

static MuxMapperList *CreateMultiplexMapperList() {

MuxMapperList *result = new MuxMapperList();

// Here, register all multiplex mappers from above.

result->push_back(new StripeMultiplexMapper());

result->push_back(new CheckeredMultiplexMapper());

result->push_back(new SpiralMultiplexMapper());

result->push_back(new ZStripeMultiplexMapper("ZStripe", 0, 8));

result->push_back(new ZStripeMultiplexMapper("ZnMirrorZStripe", 4, 4));

result->push_back(new CoremanMapper());

result->push_back(new Kaler2ScanMapper());

result->push_back(new ZStripeMultiplexMapper("ZStripeUneven", 8, 0));

result->push_back(new P10MapperZ());

result->push_back(new ThirdMultiplexMapper("Third", 3));

return result;

}

const MuxMapperList &GetRegisteredMultiplexMappers() {

static const MuxMapperList *all_mappers = CreateMultiplexMapperList();

return *all_mappers;

}

[andrei0807]

@angelogoncalve Thanks for your response. Can you write MapSinglePanel function for my led matrix?

[andrei0807]

result->push_back(new ThirdMultiplexMapper("Third", 3)); Value 3 is correct? I think it's 5

[andrei0807]

@hzeller How are you? I added new MultiplexMapperBase class but my LED doesn't work now. Do I only have to add a new MultiplexMapperBase class? Don't I need any more settings?

[hzeller]

How is your implementation @andrei0807 ?

[andrei0807]

$ sudo ./demo D 1 --led-gpio-mapping adafruit-hat --led-multiplexing 10 --led-rows 30 --led-cols 30 I changed code and used like command line.

[andrei0807]

@hzeller Do you have time for me?

[hzeller]

Did you get it to work ? If so, send a pull request, so that others can make use of it as well.