八路抢答器电子线路设计(附C语言程序)

电子系统课程设计

P2 = 0xf7;

P0 = table[second_second]; delay(2); }

//蜂鸣器响应按周期t发音 void Play(uchar t) { }

//开始键扫描函数

void start_stop_keyscan() {

if(start_stop == 0) {

delay(8);

if((start_stop == 0)&&(!start_stop_flag))

{

uchar i; for(i=0;i<1;i++) { } BEEP=0;

BEEP=~BEEP; DelayMS(t); P0 =0x00;

start_stop_flag = 1; action = 1; TR0 = 1; state = 0; }

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电子系统课程设计

} else {

start_stop_flag = 0; } }

//八位抢答键扫描函数 uchar key_scan8() {

if(key1 == 0) {

delay(8);

if((key1 == 0)&&(!key1_flag)) {

key1_flag = 1;

number = 1; number_display = number;

}

}

else {

key1_flag = 0;

number = 0; }

if(key2 == 0) {

delay(8);

if((key2 == 0)&&(!key2_flag)) {

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电子系统课程设计

key2_flag = 1;

number = 2; number_display = number; } } else {

key2_flag = 0;

number = 0; }

if(key3 == 0) {

delay(8);

if((key3 == 0)&&(!key3_flag)) {

key3_flag = 1;

number = 3; number_display = number;

} } else {

key3_flag = 0;

number = 0; }

if(key4 == 0) {

delay(8);

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电子系统课程设计

if((key4 == 0)&&(!key4_flag)) {

key4_flag = 1;

number = 4; number_display = number; } } else {

key4_flag = 0;

number = 0; }

if(key5 == 0) {

delay(8);

if((key5 == 0)&&(!key5_flag)) {

key5_flag = 1;

number = 5; number_display = number; }

} else {

key5_flag = 0;

number = 0; }

if(key6 == 0) {

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