1.实现功能:
用LCD来显示图片结合按键来实现上一幅下一幅图片显示,加上自动播放图片功能
2.开发时间:2012年8月
3.所需环境:
Linux虚拟机,交叉编译链4.3.3,ARM开发板
4.项目描述:
(1)通过TQ2440开发板实现一个电子相册,用2440的按键实现各种操作并实现相应的中断定时
(2)主要用到Linux下多进程异步运行,进程间通信和内存共享,信号量,帧缓冲区操作,同时用到select进行监控,mmap()函数进行显示缓冲区的物理地址到用户空间的映射
(3)实现ARM开发板按键驱动和测试程序
(4)实现1341声卡移植,LCD移植
具体LCD和1341声卡移植请看我其它的博客,这里主要说一下按键驱动,其实跟以前按键驱动差不多的,还有就是测试程序
下面先看测试程序
*功能电子相册
*k1 自动放映相片带音乐
*k2停止
*k3停止或刚开始时下一幅图片
*k4停止或刚开始时上一幅图片
*
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
//把存放图片的数组包含进来
extern unsigned char IMG_20120219_165753[];
extern unsigned char IMG_20120130_142227[];
extern unsigned char IMG_dyy[];
extern unsigned char IMG_20120217_180320[];
extern unsigned char IMG_20120219_170238[];
extern unsigned char IMG_3625[];
extern unsigned char IMG_3697[];
//把计算大小的函数包含进来
extern int cgy();
extern int cgy1();
extern int cgy2();
extern int cgy3();
extern int cgy4();
extern int cgy5();
extern int cgy6();
//共享内存申请标记
#define PERM S_IRUSR|S_IWUSR
//双向循环列表:存放歌曲名
struct song
{
char songname[20];
struct song *prev;
struct song *next;
};
//孙子进程id号
pid_t gradchild;
//子进程id号
pid_t pid;
//共享内存描述标记
int shmid;
char *p_addr;
//播放标记
int first_key=1;
int play_flag=0;
//帧缓冲区的标记
int fbfd = 0;
struct fb_var_screeninfo vinfo;//记录用户可修改的显示控制器参数
unsigned long screensize = 0;
char *fbp = 0;
int x = 0,y = 0;
int i = 0;
//上一幅下一幅图片标记
int nex1 = 0;
int pre1 = 6;
int bb;
*************************************************
Function name: play
Parameter : struct song *
Description : 播放函数
Return : void
Argument : void
Autor & date : ada 09,12,07
**************************************************
void play(struct song *currentsong)
{
pid_t fd;
char *c_addr;
char *p;
int len;
char my_song[30]="/qd15/song/";
while(currentsong)
{
//创建子进程,即孙子进程
fd = fork();
if(fd == -1)
{
perror("fork");
exit(1);
}
else if(fd == 0)
{
//把歌曲名加上根路径
strcat(my_song,currentsong->songname);
p = my_song;
len = strlen(p);
//去掉文件名最后的'n'
my_song[len-1]='';
printf("THIS SONG IS %sn",my_song);
execl("/qd15/madplay","madplay",my_song,NULL);
}
else
{
//内存映射
c_addr = shmat(shmid,0,0);
//把孙子进程的id和当前播放歌曲的节点指针传入共享内存
memcpy(c_addr,&fd,sizeof(pid_t));
memcpy(c_addr + sizeof(pid_t)+1,¤tsong,4);
//显示图片函数
for(i = 0;i < 7;i++){
for(x = 0;x <= vinfo.xres;x++){
long location = x * 2 ;
switch(i){
case 0 :
bb = cgy();
memcpy(fbp + location , IMG_20120130_142227 ,bb);
break;
case 1 :
bb = cgy1();
memcpy(fbp + location , IMG_20120219_165753 ,bb);
break;
case 2 :
bb = cgy2();
memcpy(fbp + location , IMG_20120219_170238 ,bb);
break;
case 3 :
bb = cgy3();
memcpy(fbp + location , IMG_dyy ,bb);
break;
case 4 :
bb = cgy4();
memcpy(fbp + location , IMG_20120217_180320 ,bb);
break;
case 5 :
bb = cgy5();
memcpy(fbp + location , IMG_3625 ,bb);
break;
case 6 :
bb = cgy6();
memcpy(fbp + location , IMG_3697 ,bb);
break;
}
}
// munmap(fbp,screensize);
// close(fbfd);
printf("nnn");
}
//使用wait阻塞孙子进程,直到孙子进程播放完才能被唤醒;
//当被唤醒时,表示播放MP3期间没有按键按下,则继续顺序播放下一首MP3
if(fd == wait(NULL))
{
currentsong = currentsong->next;
printf("THE NEXT SONG IS %sn",currentsong->songname);
}
}
}
}
*************************************************
Function name: creat_song_list
Parameter : void
Description : 创建歌曲名的双向循环链表
Return : struct song *
Argument : void
Autor & date : ada 09.12.07
**************************************************
struct song *creat_song_list(void)
{
FILE *fd;
size_t size;
size_t len;
char *line = NULL;
struct song *head;
struct song *p1;
struct song *p2;
system("ls /qd15/song >song_list");
fd = fopen("song_list","r");
p1 = (struct song *)malloc(sizeof(struct song));
printf("==================================song list=====================================n");
system("ls /qd15/song");
printf("n");
printf("================================================================================n");
size = getline(&line,&len,fd);
strncpy(p1->songname,line,strlen(line));
head = p1;
while((size = getline(&line,&len,fd)) != -1)
{
p2 = p1;
p1 = (struct song *)malloc(sizeof(struct song));
strncpy(p1->songname,line,strlen(line));
p2->next = p1;
p1->prev = p2;
}
p1->next = head;
head->prev = p1;
p1 = NULL;
p2 = NULL;
system("rm -rf song_list");
return head;
}
*************************************************
Function name: startplay
Parameter : pid_t *,struct song *
Description : 开始播放函数
Return : void
Argument : void
Autor & date : ada 09.12.07
**************************************************
void startplay(pid_t *childpid,struct song *my_song)
{
pid_t pid;
int ret;
//创建子进程
pid = fork();
if(pid > 0)
{
*childpid = pid;
play_flag = 1;
sleep(1);
//把孙子进程的pid传给父进程
memcpy(&gradchild,p_addr,sizeof(pid_t));
}
else if(0 == pid)
{
//子进程播放MP3函数
play(my_song);
}
}
*************************************************
Function name: my_pause
Parameter : pid_t
Description : 暂停函数
Return : void
Argument : void
Autor & date : ada 09,12,07
**************************************************
void my_pause(pid_t pid)
{
printf("=======================PAUSE!PRESS K1 TO CONTINUE===================n");
kill(pid,SIGSTOP); //对孙子进程发送SKGSTOP信号
play_flag = 0;
}
*************************************************
Function name: my_pause
Parameter : pid_t
Description : 停止播放函数
Return : void
Argument : void
Autor & date : ada 09,12,07
**************************************************
void my_stop(pid_t g_pid)
{
printf("=======================STOP!PRESS K1 TO START PLAY===================n");
kill(g_pid,SIGKILL); //对孙子进程发送SKGKILL信号
kill(pid,SIGKILL); //对子进程发送SKGKILL信号
first_key=1;
}
*************************************************
Function name: conti_play
Parameter : pid_t
Description : 继续函数
Return : void
Argument : void
Autor & date : ada 09,12,07
**************************************************
void conti_play(pid_t pid)
{
printf("===============================CONTINUE=============================n");
kill(pid,SIGCONT); //对孙子进程发送SIGCONT信号
play_flag=1;
}
*************************************************
Function name: next
Parameter : pid_t
Description : 下一首函数
Return : void
Argument : void
Autor & date : ada 09.12.07
**************************************************
void next(pid_t next_pid)
{
struct song *nextsong;
printf("===============================NEXT MP3=============================n");
//从共享内存获得孙子进程播放歌曲的节点指针
memcpy(&nextsong,p_addr + sizeof(pid_t)+1,4);
//指向下首歌曲的节点
nextsong = nextsong->next;
//杀死当前歌曲播放的子进程,孙子进程
kill(pid,SIGKILL);
kill(next_pid,SIGKILL);
wait(NULL);
startplay(&pid,nextsong);
}
*************************************************
Function name: prev
Parameter : pid_t
Description : 上一首函数
Return : void
Argument : void
Autor & date : yuanhui 09.12.08
**************************************************
void prev(pid_t prev_pid)
{
struct song *prevsong;
//从共享内存获得孙子进程播放歌曲的节点指针
printf("===============================PRIOR MP3=============================n");
memcpy(&prevsong,p_addr + sizeof(pid_t)+1,4);
//指向上首歌曲的节点
prevsong = prevsong->prev;
//杀死当前歌曲播放的子进程,孙子进程
kill(pid,SIGKILL);
kill(prev_pid,SIGKILL);
wait(NULL);
startplay(&pid,prevsong);
}
//下一个图片
void next1(int i)
{
for(x = 0;x <= vinfo.xres;x++){
long location = x * 2 ;
switch(i){
case 0 :
bb = cgy();
memcpy(fbp + location , IMG_20120130_142227 ,bb);
break;
case 1 :
bb = cgy1();
memcpy(fbp + location , IMG_20120219_165753 ,bb);
break;
case 2 :
bb = cgy2();
memcpy(fbp + location , IMG_20120219_170238 ,bb);
break;
case 3 :
bb = cgy3();
memcpy(fbp + location , IMG_dyy ,bb);
break;
case 4 :
bb = cgy4();
memcpy(fbp + location , IMG_20120217_180320 ,bb);
break;
case 5 :
bb = cgy5();
memcpy(fbp + location , IMG_3625 ,bb);
break;
case 6 :
bb = cgy6();
memcpy(fbp + location , IMG_3697 ,bb);
break;
}
}
// nex1++;
}
//上一张图片
void prev1(int i)
{
for(x = 0;x <= vinfo.xres;x++){
long location = x * 2 ;
switch(i){
case 0 :
bb = cgy();
memcpy(fbp + location , IMG_20120130_142227 ,bb);
break;
case 1 :
bb = cgy1();
memcpy(fbp + location , IMG_20120219_165753 ,bb);
break;
case 2 :
bb = cgy2();
memcpy(fbp + location , IMG_20120219_170238 ,bb);
break;
case 3 :
bb = cgy3();
memcpy(fbp + location , IMG_dyy ,bb);
break;
case 4 :
bb = cgy4();
memcpy(fbp + location , IMG_20120217_180320 ,bb);
break;
case 5 :
bb = cgy5();
memcpy(fbp + location , IMG_3625 ,bb);
break;
case 6 :
bb = cgy6();
memcpy(fbp + location , IMG_3697 ,bb);
break;
}
}
// nex1--;
}
*************************************************
Function name: main
Parameter : void
Description : 主函数
Return : int
Argument : void
Autor & date : ada 09.12.07
**************************************************
int main(void)
{
int buttons_fd;
int key_value;
struct song *head;
fbfd = open("/dev/fb0",O_RDWR);//打开/dev/fb0用于操作LCD
if(!fbfd){
printf("Error : cannot open framebuffer device.n");
exit (1);
}
printf("The framebuffer device was opened successfully n");
if(ioctl(fbfd,FBIOGET_VSCREENINFO,&vinfo)){//获得可变屏幕参数
printf("Error reading variable information.n");
exit(1);
}
printf("%dx%d, �ppn",vinfo.xres,vinfo.yres,vinfo.bits_per_pixel);
if(vinfo.bits_per_pixel != 16) {
printf("Error:not supported bits_per_pixer,it only supports 16 bit colorn");
exit(1);
}
screensize = vinfo.xres * vinfo.yres * 2;//16位2个字节
//将显示缓冲区的物理地址映射到用户空间
fbp = (char *)mmap(0,screensize,PROT_READ | PROT_WRITE,MAP_SHARED,fbfd,0);
if((int)fbp == -1){
printf("Error: failed to map framebuffer device to memory .n");
exit(4);
}
printf("The framebuffer device was mapped to memory successfully.n");
//打开设备文件
buttons_fd = open("/dev/buttons", 0);
if (buttons_fd < 0) {
perror("open device buttons");
exit(1);
}
//创建播放列表
head = creat_song_list();
printf("===================================OPTION=======================================nnnn");
printf(" K1:START/PAUSE K2:STOP K3:NEXT K4:PRIORnnnn");
printf("================================================================================n");
//共享内存:用于存放子进程ID,播放列表位置
if((shmid = shmget(IPC_PRIVATE,5,PERM))== -1)
exit(1);
p_addr = shmat(shmid,0,0);
memset(p_addr,'',1024);
while(1)
{
fd_set rds;
int ret;
FD_ZERO(&rds);
FD_SET(buttons_fd, &rds);
//监听获取键值
ret = select(buttons_fd + 1, &rds, NULL, NULL, NULL);
if (ret < 0)
{
perror("select");
exit(1);
}
if (ret == 0)
printf("Timeout.n");
else if (FD_ISSET(buttons_fd, &rds))
{
int ret = read(buttons_fd, &key_value, sizeof key_value);
if (ret != sizeof key_value)
{
if (errno != EAGAIN)
perror("read buttonsn");
continue;
}
else
{
//printf("buttons_value: %dn", key_value+1);
//首次播放并自动显示图片,必须是按键1
if(first_key){
switch(key_value)
{
case 0:
startplay(&pid,head);
first_key=0;
break;
case 1:
case 2:
if(nex1 == 7)
nex1 = 0;
next1(nex1);
pre1 = nex1 - 1;
nex1++;
break;
case 3:
//printf("=======================PRESS K1 TO START PLAY===================n");
//if(nex1 >= 0)
// nex1 = nex1 - 2;
if(pre1 == -1 )
pre1 = 6;
prev1(pre1);
nex1 = pre1+1;
pre1--;
break;
default:
printf("=======================PRESS K1 TO START PLAY===================n");
break;