P10 Led + arduino uno(8 does not display images when it is bigger than the panel

Hi

sorry my english is bad.

I use the code below. 4x2, 5x3 and send data via COM , the data is not going.
but when I edit and send 7x1,3x2, the data I send via COM is written on the LED.

I would appreciate your help on sending text to the 5x3 led screen on the following code
Arduino Uno R3

The demo samples in the dmd library are working fine in the latin 5x3 or 4x2 scale.

#include <SPI.h>
#include <DMD.h>
#include <TimerOne.h>
#include “Arial43.h”

char stringa[20];
int i = 0;

#define DISPLAYS_ACROSS 4
#define DISPLAYS_DOWN 2
DMD dmd(DISPLAYS_ACROSS, DISPLAYS_DOWN);

void ScanDMD()
{
dmd.scanDisplayBySPI();
}

void setup(void)
{
Timer1.initialize( 500 );
Timer1.attachInterrupt( ScanDMD );
dmd.selectFont(Arial43);
dmd.clearScreen( true );
Serial.begin(57600);
}

void loop(void)
{
// Read line from Serial
memset(stringa, 0, sizeof(stringa)); // set string contents to zero
Serial.setTimeout(100); // second input timeout
i = Serial.readBytesUntil(’\n’, stringa, sizeof(stringa)-1); // Read line of input
if(i > 0) { // Display line if anything was read

Serial.println(stringa);

dmd.clearScreen(true);

dmd.drawString( 4, 10, stringa , strlen(stringa), GRAPHICS_NORMAL );
}
}