32x32 LED Matrix

[woohaeng]

Hello!

Do you have more give it to free up memory?
Reduce the value below, meaning there any? (3 -> 1)

Code: Select all

  // Allocate and initialize matrix buffer:
  int buffsize  = 32 * nRows * 1, // x3 = 3 bytes holds 4 planes "packed"


Receives data to the serial port must be displayed in a matrix, which is unable to solve the problem of memory.
Let me know how memory can be obtained.

[pburgess]

Hi there,

No, you can't reduce the memory usage in the library...every pixel of the display must be accounted for.

It should be just possible to handle serial input and the LED matrix together, but you will need to be super careful with memory elsewhere. Places to look are library #includes (Wire.h is pretty memory-hungry) and your own program variables, especially strings (which should instead be placed in PROGMEM).

[wonderroom]

Hi,

Thanks for this, I have been able to sort this out and it's working fine for the Strings, however now when getting to the creation of the Ethernet class EthernetClient object it is failing, and I cannot find a way to get around this in the same way as the String, is it possible to have the Arduino Ethernet shield running with the Matrix?

Thanks

[wonderroom]

Hi,

I just went out today and bought an Arduino Mega as I thought the only real issue seems to be the SRAM at the moment, as it didn't work, I am just noticing some mentions of a different wiring layout for the mega (like here viewtopic.php?f=47&t=25955) where it mentions a new wiring digram will be released for it soon, do you know if this diagram is available now?

Cheers
Chris

[pburgess]

Oh! Ethernet! Heck yeah, that library's going to require a TON of RAM. No way to do the 32x32 matrix and Ethernet together on an Uno.

As for the Arduino Mega...I do seem to recall some users getting the matrix working, but whether or not this can also work with the Ethernet shield, I'm not sure. There may be pin conflicts, or there may be timing issues of trying to handle network access and driving the display simultaneously. For pin selection, here's the relevant comments from the RGBmatrixPanel library source:

Code: Select all

// Arduino Mega hasn't actually been tested -- use at your own peril!
// Because digital pins 2-7 don't map to a contiguous port register,
// the Mega will require connecting the matrix data lines to different
// pins.  Ports A, C, and L all offer the requisite contiguous 6 bits.
// I wanted to use PORTL in order to keep the external memory interface
// free, but accessing the upper PORT registers in assembly seems to
// require some additional flaming hoops and doesn't work with the
// inline code here.  PORTA is used instead (Mega pins 22-29, though
// only 24-29 are actually connected to the LED matrix).  Clock may be
// any pin on PORTB -- on the Mega, this CAN'T be pins 8 or 9 (these
// are on PORTH), thus the wiring will need to be slightly different
// than the tutorial's explanation on the Uno, etc.  Pins 10-13 are all
// fair game for the clock, as are pins 50-53.
#define DATAPORT PORTA
#define DATADIR  DDRA
#define SCLKPORT PORTB

[adafruit_support_rick]

The Ethernet Shield picks up SPI from the ICSP header on the Mega, so there shouldn't be any pinout problems between the shield and the Mega.

Mega pins 50 (MISO), 51 (MOSI), 52 (SCK), 53 (SS) will no longer be fair game, however, as these share the SPI signals with the ICSP header.

[wonderroom]

Hi,

cheers, got it working on the Mega, and I have been using the wifi rather than ethernet, all working fine until i try and process information on a webpage then it breaks the matrix, I guess because of the RAM again.

Although I am having another different issue, I wanted to ask if there is anything in the libraries to animated objects, for example I have made quite a complicated image made with lines pixels and a rectangle, is there anything in the library for moving something like this across the matrix? I have been trying to create arrays and loops to no avail right now.

Thanks

[adafruit_support_rick]

There's no animation support in the library. Sorry.

Animation typically requires redrawing the background as the object moves away from it, and then redrawing the object in the new location. Is this what you're having difficulty with?

[wonderroom]

Hi, Thanks for your help,

Quick question, do you have libraries for this 32x32 display to work with Raspberry Pi?

Thanks

[pburgess]

We don't, and I'm uncertain if there ever will be, due to timing issues on the Pi.

There might be some hope...I have seen a photo of one bring driven by a Raspberry Pi (I think it was on Google+ maybe?) in a 1-bit-each R/G/B configuration. Just how steady the image is, and whether this can be expanded to multiple bits, I have no idea.

[wonderroom]

Ok thanks, will look into it.


One other question, is there some form of freeze state for the 32x32 Matrix?

I am having an issue with the sketch I am developing in which I am displaying some information on the matrix, I then want to connect to a webpage and get a new set of data, keeping the data on the matrix until I have gained the new data, in theory it works fine, however when the arduino tries to get the new set of data from a webpage the matrix goes a bit crazy, with random lines and glitching. The only work around I have managed is to set the entire screen to black before I get the new data, however this then gives me around a 4 second delay with nothing on the screen, which is not ideal. Any fixes that you know of?

Thanks
Chris
Wonder Room

[wonderroom]

Issue fixed,

If anyone else is having similar issues, it was that the pins had to change, this is not just for the ethernet, but also the wifi shield.

As far as I could see pins 10 and 12 cannot be used, so I used 2 and 3 instead.