手头有一个80年代很流行的LED数字钟，采用TMS3450驱动，一般采用市电的50或60HZ频率作为数字钟的基准频率，走时准确度很低，也比较耗电，功能也单一，打算将其淘汰用单片机做个数码钟。但是舍不得这个90x28mm的大屏，打算将其利用一下。本来打算上网找个现成的驱动代码，但是找了半天也没有找到，只得自己写了一个，现在分享出来，请大家指教。
TMS3450数字钟的LED屏幕同普通数码管区别很大，是双阴极LED屏幕，共四个数码管，还有冒号、上午、下午等标志，例如小时的两个数码管共用6-12脚，分钟的两个数码管共用13-19脚，采用双阴极动态扫描，上午、冒号由阴极K1负责，如下图所示，下面是驱动代码：
#include <reg52.h>
sbit LED4B2K_K1_PIN = P3^6;
sbit LED4B2K_K2_PIN = P3^7;
#define LED4B2K_SetHourSeg(dat) P1 = dat
#define LED4B2K_SetMinuteSeg(dat) P2 = dat
#define LED4B2K_EnableK1() { LED4B2K_K2_PIN = 0; LED4B2K_K1_PIN = 1; }
#define LED4B2K_EnableK2() { LED4B2K_K1_PIN = 0; LED4B2K_K2_PIN = 1; }
//小时高位为0时消隐显示，将原本显示数字0的小时高位共阴1的0x06和共阴2的0x0D码表都改为0
code unsigned char DispCode11[10] = {0x00,0x00,0x06,0x06,0x00,0x06,0x06,0x02,0x06,0x06}; //小时高位共阴1
code unsigned char DispCode12[10] = {0x00,0x09,0x07,0x0B,0x0B,0x0A,0x0E,0x09,0x0F,0x0B}; //小时高位共阴2
code unsigned char DispCode21[10] = {0x68,0x00,0x38,0x30,0x50,0x70,0x78,0x00,0x78,0x70}; //小时低位共阴1
code unsigned char DispCode22[10] = {0x70,0x30,0x50,0x70,0x30,0x60,0x60,0x70,0x70,0x70}; //小时低位共阴2
code unsigned char DispCode31[10] = {0x07,0x06,0x03,0x07,0x06,0x05,0x05,0x07,0x07,0x07}; //分钟高位共阴1
code unsigned char DispCode32[10] = {0x0D,0x00,0x0E,0x06,0x03,0x07,0x0F,0x00,0x0F,0x07}; //分钟高位共阴2
code unsigned char DispCode41[10] = {0x68,0x00,0x38,0x30,0x50,0x70,0x78,0x00,0x78,0x70}; //分钟低位共阴1
code unsigned char DispCode42[10] = {0x70,0x30,0x50,0x70,0x30,0x60,0x60,0x70,0x70,0x70}; //分钟低位共阴2
void Display(unsigned char hour, unsigned char minute, unsigned char isSecond, unsigned char isFirst)
{
unsigned char hour1, hour2, minute1, minute2, seghour1, seghour2, segminute1, segminute2;
hour1 = hour >> 4;
hour2 = hour & 0x0F;
minute1 = minute >> 4;
minute2 = minute & 0x0F;
seghour1 = DispCode11[hour1] | DispCode21[hour2];
seghour2 = DispCode12[hour1] | DispCode22[hour2];
segminute1 = DispCode31[minute1] | DispCode41[minute2];
segminute2 = DispCode32[minute1] | DispCode42[minute2];
if(isSecond) segminute1 |= 0x80;
if(isFirst)
{
LED4B2K_SetHourSeg(seghour1);
LED4B2K_SetMinuteSeg(segminute1);
LED4B2K_EnableK1();
}
else
{
LED4B2K_SetHourSeg(seghour2);
LED4B2K_SetMinuteSeg(segminute2);
LED4B2K_EnableK2();
}
}
#define Delay10ms() { unsigned int iDelay = 1250; while(--iDelay); }
void main(void)
{
bit isFirst = 1, isSecond = 0;
unsigned char hour = 0x12;
unsigned char minute = 0x34;
unsigned char count = 0;
while(1)
{
if(++count == 50) //秒闪烁
{
count = 0;
isSecond = !isSecond;
}
isFirst = !isFirst; //分别扫描K1和K2
Display(hour, minute, isSecond, isFirst);
Delay10ms();
}
}
