How do I make the letters on my Arduino LED matrix scroll faster?

Question

////*************************************************************************
////----------------1.开发环境:Arduino IDE or Visual Studio 2010----------------
////----------------2.使用开发板型号：Arduino UNO          ----------------
////----------------3.单片机使用晶振：16M                   ----------------
////----------------4.店铺名称：大学生电子商铺/小强电子设计  ----------------
////----------------5.淘宝网址：Ilovemcu.taobao.com       ----------------
////----------------        52dpj.taobao.com                ----------------
////----------------6.作者：神秘藏宝室              ----------------
////***********************************************************************

#include <Arduino.h>

//IO配置
#define LEDARRAY_D 5
#define LEDARRAY_C 6
#define LEDARRAY_B 7
#define LEDARRAY_A 8
#define LEDARRAY_G 9
#define LEDARRAY_DI 10
#define LEDARRAY_CLK 11
#define LEDARRAY_LAT 12

#define led 13


#define Display_Num_Word 2              //液晶能显示的汉字个数

unsigned char Display_Buffer[8];
unsigned char Display_Swap_Buffer[Display_Num_Word][32]={0};                    //显示缓冲区
bool Shift_Bit = 0;
bool Flag_Shift = 0;
unsigned char Timer0_Count = 0;
unsigned char temp = 0x80;
unsigned char Shift_Count = 0;
unsigned char Display_Word_Count = 0;

#define Num_Of_Word 33
const unsigned char Word[Num_Of_Word][32] = 
{
0xFF,0xFF,0xFF,0x07,0xBB,0xBB,0xBB,0x87,0xBB,0xBD,0xBD,0xBD,0xBB,0x07,0xFF,0xFF,/*"B",0*/
0xFF,0xFF,0xFF,0xC7,0xBB,0x7D,0x7D,0x7D,0x7D,0x7D,0x7D,0x7D,0xBB,0xC7,0xFF,0xFF,/*"O"*/
0xFF,0xFF,0xFF,0x83,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0x83,0xFF,0xFF,/*"I",0*/
0xFF,0xFF,0xFF,0x1F,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0x01,0xFF,0xFF,
0xFF,0xFF,0xFF,0xC1,0xBD,0xBD,0xBF,0xDF,0xE7,0xFB,0xFD,0xBD,0xBD,0x83,0xFF,0xFF,/*"S"*/
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0xEF,0xEF,0xE7,0xD7,0xD7,0xDB,0xC3,0xBB,0xBD,0xBD,0x18,0xFF,0xFF,/*"A",0*/
0xFF,0xFF,0xFF,0x03,0xBD,0xBD,0xBD,0x83,0xB7,0xB7,0xBB,0xBB,0xBD,0x1C,0xFF,0xFF,/*"R",0*/
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0x81,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0xEF,0xEF,0xE7,0xD7,0xD7,0xDB,0xC3,0xBB,0xBD,0xBD,0x18,0xFF,0xFF,/*"A",0*/
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0x83,0xBD,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBD,0x83,0xFF,0xFF,
0xFF,0xFF,0xFF,0x1F,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0x01,0xFF,0xFF,
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0x81,0xFF,0xFF,
0xFF,0xFF,0xFF,0xEF,0xEF,0xE7,0xD7,0xD7,0xDB,0xC3,0xBB,0xBD,0xBD,0x18,0xFF,0xFF,/*"A",0*/
0xFF,0xFF,0xFF,0x03,0xBD,0xBD,0xBD,0x83,0xB7,0xB7,0xBB,0xBB,0xBD,0x1C,0xFF,0xFF,/*"R",0*/
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0xC1,0xBD,0xBD,0xBF,0xDF,0xE7,0xFB,0xFD,0xBD,0xBD,0x83,0xFF,0xFF,/*"S"*/
0xFF,0xFF,0xFF,0x83,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0x83,0xFF,0xFF,/*"I",0*/
0xFF,0xFF,0xFF,0xC3,0xBB,0xBB,0x7F,0x7F,0x7F,0x71,0x7B,0xBB,0xBB,0xC7,0xFF,0xFF,/*"G",0*/
0xFF,0xFF,0xFF,0xBF,0x83,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0xC7,0xBB,0x7D,0x7D,0x7D,0x7D,0x7D,0x7D,0x7D,0xBB,0xC7,0xFF,0xFF,/*"O"*/
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0x01,0x6D,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xC7,0xFF,0xFF,/*"T",0*/
0xFF,0xFF,0xFF,0x18,0xBD,0xBD,0xBD,0xBD,0x81,0xBD,0xBD,0xBD,0xBD,0x18,0xFF,0xFF,/*"H",0*/
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0x81,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0x07,0xBB,0xBB,0xBB,0x87,0xBB,0xBD,0xBD,0xBD,0xBB,0x07,0xFF,0xFF,/*"B",0*/
0xFF,0xFF,0xFF,0x1F,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0x01,0xFF,0xFF,
0xFF,0xFF,0xFF,0xEF,0xEF,0xE7,0xD7,0xD7,0xDB,0xC3,0xBB,0xBD,0xBD,0x18,0xFF,0xFF,/*"A",0*/
0xFF,0xFF,0xFF,0x83,0xBD,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBD,0x83,0xFF,0xFF,
0xFF,0xFF,0xFF,0xBE,0xBD,0xBB,0xB7,0xB7,0xBB,0xBB,0xBD,0xBD,0xBE,0xBE,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0x07,0xBB,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xBB,0x07,0xFF,0xFF,/*"D",0*/
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0x81,0xFF,0xFF,
0xFF,0xFF,0xFF,0xEF,0xEF,0xE7,0xD7,0xD7,0xDB,0xC3,0xBB,0xBD,0xBD,0x18,0xFF,0xFF,/*"A",0*/
0xFF,0xFF,0xFF,0x01,0x6D,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xC7,0xFF,0xFF,/*"T",0*/
0xFF,0xFF,0xFF,0x18,0xBD,0xBD,0xBD,0xBD,0x81,0xBD,0xBD,0xBD,0xBD,0x18,0xFF,0xFF,/*"H",0*/
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,/*" Space",0*/
0xFF,0xFF,0xFF,0xDF,0xD7,0xB7,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xBE,0xBD,0xBB,0xB7,0xB7,0xBB,0xBB,0xBD,0xBD,0xBE,0xBE,0xFF,0xFF,
0xFF,0xFF,0xFF,0x83,0xBD,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBD,0x83,0xFF,0xFF,
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0x81,0xFF,0xFF,
0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0x83,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xFF,0xFF,
0xFF,0xFF,0xFF,0x1F,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0xBF,0x01,0xFF,0xFF,
};
void setup()
{
    pinMode(LEDARRAY_D, OUTPUT); 
    pinMode(LEDARRAY_C, OUTPUT);
    pinMode(LEDARRAY_B, OUTPUT);
    pinMode(LEDARRAY_A, OUTPUT);
    pinMode(LEDARRAY_G, OUTPUT);
    pinMode(LEDARRAY_DI, OUTPUT);
    pinMode(LEDARRAY_CLK, OUTPUT);
    pinMode(LEDARRAY_LAT, OUTPUT);

    Clear_Display();
}

void loop()
{
    unsigned int i;
    for(i = 0;i<30;i++)
    {
        Display(Display_Swap_Buffer);
    }
    Display_Word_Count = Shift_Count/16;                //计算当前显示第几个字
    Calc_Shift();                                       

    Shift_Count++;

    if(Shift_Count == (Num_Of_Word+Display_Num_Word)*16 )               //移动次数
    {
        Shift_Count = 0;                
    }   
}

//************************************************************
//清空缓冲区
//************************************************************
void Clear_Display()
{
    unsigned char i,j;
    for(j = 0 ; j < Display_Num_Word; j++)
    {
        for(i = 0 ; i < 32 ;i++)
        {
            Display_Swap_Buffer[j][i] = 0xff;               //0=显示  1=不显示   
        }
    }
}

//************************************************************
//计算移动数据，存在在缓冲器
//************************************************************
void Calc_Shift()
{
    unsigned char i;

    for(i = 0;i < 16;i++)
    {
        if((Display_Swap_Buffer[0][16+i]&0x80) == 0)                                    //每行第一个字节移位
        {
            Display_Swap_Buffer[0][i] = (Display_Swap_Buffer[0][i] << 1)&0xfe;          //最低位清零 
        }
        else
        {
            Display_Swap_Buffer[0][i] = (Display_Swap_Buffer[0][i] << 1)|0x01;          //最低位置一     
        }

        if((Display_Swap_Buffer[1][i]&0x80) == 0)                                   //每行第二个字节移位
        {
            Display_Swap_Buffer[0][16+i] = (Display_Swap_Buffer[0][16+i] << 1)&0xfe;            //最低位清零 
        }
        else
        {
            Display_Swap_Buffer[0][16+i] = (Display_Swap_Buffer[0][16+i] << 1)|0x01;            //最低位置一     
        }

        if((Display_Swap_Buffer[1][16+i]&0x80) == 0)                                    //每行第三个字节移位
        {
            Display_Swap_Buffer[1][i] = (Display_Swap_Buffer[1][i] << 1)&0xfe;          //最低位清零 
        }
        else
        {
            Display_Swap_Buffer[1][i] = (Display_Swap_Buffer[1][i] << 1)|0x01;          //最低位置一     
        }

        if(Shift_Count%16 < 8 && Display_Word_Count < Num_Of_Word)
        {
            Shift_Bit = Word[Display_Word_Count][i]&temp;
        }
        else if(Shift_Count%16 < 16 && Display_Word_Count < Num_Of_Word)
        {
            Shift_Bit = Word[Display_Word_Count][16+i]&temp;
        }
        else
        {
            Shift_Bit = 1;                      //把字移出缓冲区
        }

        if( Shift_Bit == 0)                                                     //后8位移位
        {
            Display_Swap_Buffer[1][16+i] = (Display_Swap_Buffer[1][16+i] << 1)&0xfe;        //最低位清零
        }
        else
        {
            Shift_Bit = 1;
            Display_Swap_Buffer[1][16+i] = (Display_Swap_Buffer[1][16+i] << 1)|0x01;        //最低位置一             
        }

    }
    temp = (temp>>1)&0x7f;
    if(temp == 0x00)
    {
        temp = 0x80;
    }
}
//************************************************************
//num为字数  dat[][32]为字模的名称
//*************************************************************
void Display(const unsigned char dat[][32])                 
{
    unsigned char i;

    for( i = 0 ; i < 16 ; i++ )
    {
        digitalWrite(LEDARRAY_G, HIGH);     //更新数据时候关闭显示。等更新完数据，打开138显示行。防止重影。

        Display_Buffer[0] = dat[0][i];      
        Display_Buffer[1] = dat[0][i+16];
        Display_Buffer[2] = dat[1][i];
        Display_Buffer[3] = dat[1][i+16];

    Display_Buffer[4] = dat[2][i];
    Display_Buffer[5] = dat[2][i+16];
    Display_Buffer[6] = dat[3][i];
    Display_Buffer[7] = dat[3][i+16];

    Send(Display_Buffer[7]);
    Send(Display_Buffer[6]);
    Send(Display_Buffer[5]);
    Send(Display_Buffer[4]);

        Send(Display_Buffer[3]);
        Send(Display_Buffer[2]);
        Send(Display_Buffer[1]);
        Send(Display_Buffer[0]);

        digitalWrite(LEDARRAY_LAT, HIGH);                   //锁存数据
        delayMicroseconds(0.1);

        digitalWrite(LEDARRAY_LAT, LOW);
        delayMicroseconds(0.1);

        Scan_Line(i);                       //选择第i行

        digitalWrite(LEDARRAY_G, LOW);

        delayMicroseconds(100);;        //延时一段时间，让LED亮起来。               
    }   
}

//****************************************************
//扫描某一行
//****************************************************
void Scan_Line( unsigned char m)
{   
    switch(m)
    {
        case 0:         
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, LOW);                    
            break;
        case 1:                 
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, HIGH);       
            break;
        case 2:                 
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, LOW);       
            break;
        case 3:                 
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, HIGH);      
            break;
        case 4:
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, LOW);       
            break;
        case 5:
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, HIGH);      
            break;
        case 6:
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, LOW);      
            break;
        case 7:
            digitalWrite(LEDARRAY_D, LOW);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, HIGH);         
            break;
        case 8:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, LOW);       
            break;
        case 9:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, HIGH);      
            break;  
        case 10:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, LOW);      
            break;
        case 11:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, LOW);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, HIGH);         
            break;
        case 12:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, LOW);      
            break;
        case 13:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, LOW);digitalWrite(LEDARRAY_A, HIGH);         
            break;
        case 14:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, LOW);         
            break;
        case 15:
            digitalWrite(LEDARRAY_D, HIGH);digitalWrite(LEDARRAY_C, HIGH);digitalWrite(LEDARRAY_B, HIGH);digitalWrite(LEDARRAY_A, HIGH);        
            break;
        default : break;    
    }
}

//****************************************************
//发送数据
//****************************************************
void Send( unsigned char dat)
{
    unsigned char i;
    digitalWrite(LEDARRAY_CLK, LOW);
    delayMicroseconds(0);;  
    digitalWrite(LEDARRAY_LAT, LOW);
    delayMicroseconds(0);;

    for( i = 0 ; i < 8 ; i++ )
    {
        if( dat&0x01 )
        {
            digitalWrite(LEDARRAY_DI, HIGH);    
        }
        else
        {
            digitalWrite(LEDARRAY_DI, LOW);
        }


        digitalWrite(LEDARRAY_CLK, HIGH);               //上升沿发送数据
            delayMicroseconds(0);;
        digitalWrite(LEDARRAY_CLK, LOW);
            delayMicroseconds(0);;      
        dat >>= 1;

    }           
}

reduce any delays as much as practicable - if you've reduced them as far as you can, then you have achieved the maximum speed your code allows - if this isn't fast enough, then use a faster MCU, or perhaps your code can be written better, but this is unknown as the code is almost unreadable as it stands — Jaromanda X
– Jaromanda X, Commented Mar 7, 2019 at 2:42
Start by measuring the update time (microseconds). After that you may consider optimizations, for instance, faster digitalWrite, direct port access, SPI, etc. — Mikael Patel
– Mikael Patel, Commented Mar 7, 2019 at 19:48

Dorian · Accepted Answer · 2019-03-08 16:20:43Z

You have 30x loop calling Display() that inside a 16X loop calls eight Send() that inside an 8x loop makes three digital writes each taking at least 2us to complete. At a minimum, only digitalWrite takes 180ms in one pass.

Use SPI if possible or search Google for "arduino speed up digitalWrite" , here is a good article on this.

Also unrolling the 8x loop inside Send() like this can spare some ms:

   if( dat&0x01 ) digitalWrite(LEDARRAY_DI, HIGH);    
   else digitalWrite(LEDARRAY_DI, LOW);
   digitalWrite(LEDARRAY_CLK, HIGH);               //上升沿发送数据
   delayMicroseconds(0);;
   digitalWrite(LEDARRAY_CLK, LOW);
   delayMicroseconds(0);   
   if( dat&0x02 ) digitalWrite(LEDARRAY_DI, HIGH);    
   else digitalWrite(LEDARRAY_DI, LOW);
   digitalWrite(LEDARRAY_CLK, HIGH);               //上升沿发送数据
   delayMicroseconds(0);;
   digitalWrite(LEDARRAY_CLK, LOW);
   delayMicroseconds(0);  
   ........      
   if( dat&0x80 ) digitalWrite(LEDARRAY_DI, HIGH);    
   else digitalWrite(LEDARRAY_DI, LOW);
   digitalWrite(LEDARRAY_CLK, HIGH);               //上升沿发送数据
   delayMicroseconds(0);;
   digitalWrite(LEDARRAY_CLK, LOW);
   delayMicroseconds(0);

CrossRoads · Accepted Answer · 2019-08-05 22:42:56Z

These lines

    digitalWrite(LEDARRAY_LAT, HIGH);                   //锁存数据
    delayMicroseconds(0.1);

    digitalWrite(LEDARRAY_LAT, LOW);
    delayMicroseconds(0.1);

    Scan_Line(i);                       //选择第i行

    digitalWrite(LEDARRAY_G, LOW);

    delayMicroseconds(100);;        //延时一段时间，让LED亮起来。

Reduce the time in the last one. I don't think delayMicroseconds(0.1); does anything, nor does delayMicroseconds(0); found elsewhere.

I see individual pins being controlled

#define LEDARRAY_D 5
#define LEDARRAY_C 6
#define LEDARRAY_B 7
#define LEDARRAY_A 8
#define LEDARRAY_G 9
#define LEDARRAY_DI 10
#define LEDARRAY_CLK 11
#define LEDARRAY_LAT 12

You don't say what the hardware is, but I bet you replace writing individual pins with blasting data out serially to a shift register with 8 MHz SPI clock as a way speed things up. Or if you had a '1284P or '2560 board, then you could do port writes also.

Stack Exchange Network

How do I make the letters on my Arduino LED matrix scroll faster?

2 Answers 2

Your Answer

Hot Network Questions

How do I make the letters on my Arduino LED matrix scroll faster?

2 Answers 2

Your Answer

Sign up or log in

Post as a guest

Related

Hot Network Questions