4、GPIO应用程序
application.c
- #include "led.h"
- #include "key.h"
- #include "buzzer.h"
- #define MAX_VOL 20
- #define MIN_VOL 1
-
- int main(void){
- unsigned char volume = 10;
- //周期计数，忽略键盘扫描，用于蜂鸣器控制
- //如volume = 10，即20个周期有10个输出高电平
- unsigned char cycle = 0;
- led_operate(0,1);
- led_operate(1,1);
- led_operate(2,1);
- led_operate(3,1);
- while(1){
- unsigned char key_site = scan_keyboard(); //扫描按键状态
- char led_status = -1;
- //延迟10ms给蜂鸣器一个响应时间，否则在Proteus仿真环境下蜂鸣器可能由于得不到(电脑的)CPU而不响
- delayms(10);
- cycle++;
- switch(key_site){
- case 0: //按键一被按了一次
- led_status = get_led_status(0);
- if(led_status == 0){
- led_operate(0,1); //D1状态改变
- }else if(led_status == 1){
- led_operate(0,0); //D1状态改变
- }
- break;
- case 1:
- led_status = get_led_status(1);
- if(led_status == 0){
- led_operate(1,1); //D2状态改变
- }else if(led_status == 1){
- led_operate(1,0); //D2状态改变
- }
- break;
-
- case 2:
- led_status = get_led_status(2);
- if(led_status == 0){
- led_operate(2,1); //D3状态改变
- }else if(led_status == 1){
- led_operate(2,0); //D3状态改变
- }
- break;
-
- case 3:
- led_status = get_led_status(3);
- if(led_status == 0){
- led_operate(3,1); //D4状态改变
- }else if(led_status == 1){
- led_operate(3,0); //D4状态改变
- }
- break;
- case 4: //蜂鸣器音量+
- if(volume < MAX_VOL){
- volume++;
- }
- break;
-
- case 5: //蜂鸣器音量－
- if(volume > MIN_VOL){
- volume--;
- }
- break;
- default:
- break;
- }
- if(cycle >= 0){
- buzzer_open();
- }if(cycle >= volume){
- buzzer_off();
- }if(cycle >= (MAX_VOL+1)){
- cycle = 0;
- }
- }
- return 0;
- }
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