LED RGB Matrix show some letters

Hi?digita4
I think the library “rgb_matrix_1.0” is right
there is easy way to display three letter“U.P.V”
We use the example “matrix 1*1” and we add some code
If you want to display other letters ,change the ASCII what you need.

[code]


#include <rgb_matrix.h>
#include <SPI.h>

unsigned long time=0;
unsigned int tick_100ms = 0;
unsigned char counter=0;


#define N_X 1
#define N_Y 1

/*
//Interface shield ShiftOut connector
#define DATA_PIN 9
#define CLK_PIN 3
*/
//Hardware SPI
#define DATA_PIN 11
#define CLK_PIN 13

#define LATCH_PIN 8

rgb_matrix M = rgb_matrix(N_X, N_Y, DATA_PIN, CLK_PIN, LATCH_PIN);

unsigned char cmd[50]={0},cmd_num=0;
unsigned char tmp = 'A';
unsigned char st=0;
byte y[3]={20,15,21};//"A"+20="U" "A"+15="P" "A"+21="V"

void setup()
{
Serial.begin(115200);
delay(200);
}


void hook(void)
{
int i = 0;
unsigned long enter_time,exit_time;
enter_time = micros();
if((++counter)%10 == 0)
{
if(millis() - time >= 100)
{
time = millis();
tick_100ms ++;
M.move(UP,1,0);
if(tick_100ms%2 == 0)
{
}
if(tick_100ms%5 == 0)
{
M.clear();
M.put_char(0,0,tmp+y[(st++)%3],1,MULTIPLY,RED << (st%3),TOP_LAYER); // "3" in a loop
}
if(tick_100ms%10 == 0)
{
}
if(tick_100ms%20 == 0)
{
}
if(tick_100ms%50 == 0)
{
}
}
}
if(Serial.available())
{
cmd[cmd_num++] = Serial.read();
if((cmd_num>=2) && (cmd[cmd_num-1] == 0x0a) && (cmd[cmd_num-2] == 0x0d))
{
M.at_cmd(cmd);
cmd_num = 0;
}
}
exit_time = micros();
if(enter_time < exit_time)
{
if(exit_time - enter_time < 500)
{
delayMicroseconds(500 - (exit_time-enter_time));
}
}
}


void loop()
{
M.set_cur(0,0);
M.display(hook);
}[/code]