Arduino驱动MAX7219四位数码管显示时间

Arduino驱动MAX7219四位数码管显示时间
默认使用Pin 2为MOSI（数据发送）引脚，Pin 3为CS（片选）引脚，Pin 4为SCLK（时钟）引脚，如有需要请修改代码前三行的define。

#define MO 2
#define CS 3
#define CLK 4
static int time_h = 21, time_m =25, time_s = 30; //此刻时间：时，分，秒
int alarm_clock_h = 8, alarm_clock_m = 00; //闹钟时间
unsigned long time = 0;
unsigned char buffer_led[5] = { 0x00,};//缓存
void SPI_init(void) //初始化SPI引脚
{
pinMode(CLK, OUTPUT);
pinMode(MO, OUTPUT);
pinMode(CS, OUTPUT);
digitalWrite(CS, HIGH);
digitalWrite(CLK, LOW);
digitalWrite(MO, HIGH);
}
void SPI_send(unsigned char reg, unsigned char data) //spi单向16位数据发送{
int x;
/*
Serial.print("reg = ");
Serial.print(reg, HEX);
Serial.print(" data = ");
Serial.println(data, HEX);
*/
digitalWrite(CS, LOW);
for (x = 0; x < 8; x++)
{
digitalWrite(MO, 0x80 & (reg << x)); //高位在前
digitalWrite(CLK, HIGH);
digitalWrite(CLK, LOW);
}
for (x = 0; x < 8; x++)
{
digitalWrite(MO, 0x80 & (data << x)); //高位在前 digitalWrite(CLK, HIGH);
digitalWrite(CLK, LOW);
}
digitalWrite(CS, HIGH);
}
void lcd_init(void)//初始化Max7219配置
{
SPI_send(0x0b, 0x07); //scan-limit
SPI_send(0x09, 0xff); //decode mode all
SPI_send(0x0c, 0x01); //shutdown off
SPI_send(0x0f, 0x00); //off display test
SPI_send(0x0a, 0x04); //intensity
delay(100);
}
void clear(void)//清除显示
{
for (int i = 1; i <= 8; i++)
{
SPI_send(i, 0x0F);
}
}
void led_display(void)//显示时间
{
char cache = 0x00;
if ((time_h / 10) == 0)buffer_led[0] = 0x00;
else buffer_led[0] = time_h / 10;
buffer_led[1] = time_h % 10 | 0x01;
buffer_led[2] = time_m / 10;
buffer_led[3] = time_m % 10;
SPI_send(8, buffer_led[0]);
SPI_send(7, buffer_led[1]);
SPI_send(6, 0x0a);
SPI_send(5, buffer_led[2]);
SPI_send(4, buffer_led[3]);
SPI_send(3, 0x0a);
SPI_send(2, time_s / 10);
SPI_send(1, time_s % 10);
}
void get_time()//获取时间并更新显示
{
static char ss = 1;
static unsigned long time_cc = 0;
if ((millis() - time_cc) > 1000 | millis() < 150)//秒
{
if (millis() <= 200) //若系统计时器溢出时时间，time_cc重计
{
time_cc = millis();
time_s ++;
delay(150);
}
else if (millis() > 200)//秒
{
time_s += (millis() - time_cc) / 1000;
// time_cc = millis()-990; //时间快进
time_cc = millis();
buffer_led[4] = (0x01 & ss) << 5;
ss = ~ss;
}
if (time_s > 59) //分
{
if (time_s - 60 > 1)//如果有延时间隔导致秒钟大于60秒，进行分钟缺失补偿 {
time_m += time_s / 60;
if (time_s % 60 == 0)time_m--;
time_s = time_s - (time_s / 60) * 60;
}
else time_s = 0;
time_m++;
buffer_led[4] = 0x80;
if (time_m > 59)//时
{
time_h++;
time_m = (time_m - 60);
buffer_led[4] = 0xf0;
}
if (time_h > 23)
{
time_h = 0;
time_s += 5; //时间误差补偿
}
}
// Serial.print("millis="); // Serial.print(time_cc);
// Serial.print(" time="); // Serial.print(time_h);
// Serial.print(":");
// Serial.print(time_m);
// Serial.print(":");
// Serial.println(time_s); led_display();//刷新数码管显示
}
}
void setup()
{
Serial.begin(9600);
SPI_init();
lcd_init();
clear();
}
void loop()
{
get_time();
}。