【智能家居挑战赛】基于IMX8嵌入式系统和单片机USB通信的...

donatello1996 · 发表于 2022-3-17 10:20:42

项目概要：此系统功能有网络摄像头图像传输，温湿度数据采集，光照强度数据采集，大气压数据采集，网络摄像头图像远程监控，手机浏览器网页读取显示等功能，系统分为四个部分，第一部分为基于IMX8嵌入式系统的主服务器，
负责功能为：-摄像头图像采集与UDP发送
-基于TCP的HTML网页界面搭建
-USBHID主机接收

第二部分为基于单片机MCU核心板的采集模块，负责功能为
-DHT11温湿度采集
-光照强度模拟信号AD采集
-大气压数字信号读取
-USBHID从机发送，发送目标为第一部分的IMX8嵌入式系统

第三部分为基于x86电脑的QT上位机，负责功能为
-接收第一部分IMX8嵌入式系统的网络摄像头数据，协议为UDP
-接收第一部分IMX8嵌入式系统的温湿度，光照强度，大气压数据并显示，协议同样为UDP

第四部分为手机或x86电脑，使用浏览器访问第一部分IMX8嵌入式系统搭建的TCP-HTML网页界面并显示

系统要点如下：
-网络摄像头数据传输采用协议为UDP而非TCP，提高传输效率，不过可手动切换为TCP模式，使用UDP模式，由于x86PC端IP是固定的，因此UDP发送端报文只需要配置协商好的端口号，然后接收端打开该端口号的接收就可以进行大流量数据传输
-HTML网页服务器只能采用TCP方式传输，无法使用UDP
-USB通信协议为Custom HID，简化IMX8嵌入式系统部分编程复杂度，提高项目可实施性
-IMX8嵌入式系统上有片内M4核，但是普适性不高，采用普适性更高的片外MCU+USB通信

系统框图如下：

运行效果，QT上位机界面部分：

手机浏览器网页：

实物连接图拍照：

如图所示，IMX8嵌入式系统开发板既可以连接网线也可以通过无线WIFI进行通信。

IMX8嵌入式系统代码，基于Unix系统编程，使用发行版系统为Debian10。
UDP发送图片文件帧到x86PC：

int UDP_Send_Picture(socklen_t socket_send , struct sockaddr_in addr , char* filename)
{
struct Package
{
int length;
char data[UDP_FRAME_LEN];
int fin;
}picture;
socklen_t addr_len = sizeof(struct sockaddr_in);
FILE *fp;
fp = fopen(filename, "rb+");
printf("fp = %d\\n",fp);
fseek(fp, 0, SEEK_END);
int fend = ftell(fp);
fseek(fp, 0, 0);
int sendbytes;
printf("fend = %d\\n",fend);
while(fend > 0)
{
memset(picture.data, 0, sizeof(picture.data));
fread(picture.data, UDP_FRAME_LEN, 1, fp);
if(fend >= UDP_FRAME_LEN)
{
picture.length = UDP_FRAME_LEN;
picture.fin = 0;
}
else
{
picture.length = fend;
picture.fin = 1;
}
//printf("sendbytes = %d \\n",sendbytes);
sendbytes = sendto(socket_send, (char *)&picture, sizeof(struct Package), 0, (struct sockaddr*)&addr,addr_len);
if(sendbytes == -1)
{
printf("Send Picture Failed!d\\n");
return -1;
}
else
{
fend -= UDP_FRAME_LEN;
}
}
fclose(fp);
return 0;
}

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建立UDP发送套接字：

int UDP_Send_Found(socklen_t* socket_found , struct sockaddr_in *addr , char* ip , int port)
{
*socket_found = socket(AF_INET, SOCK_DGRAM, 0);
if(*socket_found == (~0))
{
printf("Create udp send socket failed!\\n");
return -1;
}
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr(ip);
addr->sin_port = htons(port);
memset(addr->sin_zero, 0, 8);
return 0;
}

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抓取V4L2 USB摄像头图像帧并保存在缓存中：

typedef struct
{
void *start;
unsigned int length;
} buffer;

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int V4l2_Grab()
{
unsigned int n_buffers;
buffers = (buffer* )malloc(req.count*sizeof(*buffers));
if (buffers == NULL)
{
printf ("Out of memory\\n");
return 0;
}
for (n_buffers = 0; n_buffers < req.count; n_buffers++)
{
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = n_buffers;
//query buffers
if (ioctl (fd_video,VIDIOC_QUERYBUF, &buf) == -1)
{
printf("query buffer error\\n");
return(0);
}
buffers[n_buffers].length = buf.length;
buffers[n_buffers].start = mmap(NULL,buf.length,PROT_READ |PROT_WRITE, MAP_SHARED,
fd_video, buf.m.offset);
if (buffers[n_buffers].start == MAP_FAILED)
{
printf("buffer map error\\n");
return 0;
}
}
for (n_buffers = 0; n_buffers < req.count; n_buffers++)
{
buf.index = n_buffers;
ioctl(fd_video, VIDIOC_QBUF, &buf);
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
ioctl (fd_video, VIDIOC_STREAMON, &type);
ioctl(fd_video, VIDIOC_DQBUF, &buf);
// printf("grab yuyv OK!\\n");
return 1;
}

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int Yuyv_2_RGB888(buffer* input_buffers,unsigned char *output_buffer)
{
int i,j,r1,g1,b1,r2,g2,b2;
unsigned char y1,y2,u,v;
unsigned char *pointer;
pointer =(unsigned char*)input_buffers[0].start;
for(i=0;i<IMAGEHEIGHT;i++)
{
for(j=0;j<IMAGEWIDTH/2;j++)
{
y1 = *( pointer + (i*IMAGEWIDTH/2+j)*4);
u = *( pointer + (i*IMAGEWIDTH/2+j)*4 + 1);
y2 = *( pointer + (i*IMAGEWIDTH/2+j)*4 + 2);
v = *( pointer + (i*IMAGEWIDTH/2+j)*4 + 3);
r1 = y1 + 1.042*(v-128);
g1 = y1 - 0.34414*(u-128) - 0.71414*(v-128);
b1 = y1 + 1.772*(u-128);
r2 = y2 + 1.042*(v-128);
g2 = y2 - 0.34414*(u-128) - 0.71414*(v-128);
b2 = y2 + 1.772*(u-128);
if(r1>255)
r1 = 255;
else if(r1<0)
r1 = 0;
if(b1>255)
b1 = 255;
else if(b1<0)
b1 = 0;
if(g1>255)
g1 = 255;
else if(g1<0)
g1 = 0;
if(r2>255)
r2 = 255;
else if(r2<0)
r2 = 0;
if(b2>255)
b2 = 255;
else if(b2<0)
b2 = 0;
if(g2>255)
g2 = 255;
else if(g2<0)
g2 = 0;
*(output_buffer + (i*IMAGEWIDTH/2+j)*6 ) = (unsigned char)r1;
*(output_buffer + (i*IMAGEWIDTH/2+j)*6 + 1) = (unsigned char)g1;
*(output_buffer + (i*IMAGEWIDTH/2+j)*6 + 2) = (unsigned char)b1;
*(output_buffer + (i*IMAGEWIDTH/2+j)*6 + 3) = (unsigned char)r2;
*(output_buffer + (i*IMAGEWIDTH/2+j)*6 + 4) = (unsigned char)g2;
*(output_buffer + (i*IMAGEWIDTH/2+j)*6 + 5) = (unsigned char)b2;
}
}
// printf("change to RGB OK! \\n");
free(input_buffers);
return 0;
}

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主循环处理：

while(1)
{
V4l2_Grab();
if(buffers != NULL)
{
Yuyv_2_RGB888(buffers,frame_buffer_video);
Encode_Jpeg(frame_buffer_video , 640 , 480 , (char*)"/home/proj/1.jpg");
UDP_Send_Picture(socklen_udp_camera_send,sockaddr_udp_camera_send,(char*)"/home/proj/1.jpg");
}
}

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建立HID枚举主设备并枚举特定VID/PID从设备（HID单片机）：

handle = hid_open(2020, 2020, NULL);
if (!handle)
{
printf("unable to open hidraw device\\n");
return -1;
}
hid_set_nonblocking(handle, 1);
printf("open hidraw device\\n");

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USBHID接收并通过UDP发送，使用单独线程进行：

pthread_t tid_udp_send;
pthread_create(&tid_udp_send , NULL , Thread_UDP_Send , (void*)&t2a);

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void * Thread_UDP_Send(void *arg)
{
thread2_args t2a = *(thread2_args*)arg;
int res , sendbytes;
socklen_t addr_len = sizeof(struct sockaddr_in);
uint8_t buf_usb_recv[64];
uint8_t buf_udp_send[UDP_FRAME_LEN];
while(1)
{
res = hid_read(handle, buf_usb_recv, 64);
if(res > 0)
{
printf("res = %d buf[2] = %d buf[3] = %d buf[4] = %d buf[5] = %d\\n",res ,
buf_usb_recv[2] , buf_usb_recv[3] , buf_usb_recv[4] , buf_usb_recv[5]);
buf_udp_send[0] = 0x12;
buf_udp_send[1] = 0x23;
buf_udp_send[2] = 0x34;
buf_udp_send[3] = 0x45;
buf_udp_send[4] = buf_usb_recv[2];
dht11_temp = buf_usb_recv[2];
buf_udp_send[5] = buf_usb_recv[3];
dht11_humi = buf_usb_recv[3];
buf_udp_send[6] = buf_usb_recv[4];
buf_udp_send[7] = buf_usb_recv[5];
adc_value = (buf_usb_recv[4] << 8) | buf_usb_recv[5];
sendbytes = sendto(t2a.fd, buf_udp_send, UDP_FRAME_LEN , 0, (struct sockaddr*)&t2a.addr , addr_len);
}
}
}

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TCP-HTML网页的接收和发送采用两个单独线程进行：

pthread_t tid_tcp_web_recv;
pthread_create(&tid_tcp_web_recv , NULL , Thread_TCP_Web_Recv , NULL);
pthread_create(&id_tcp_send , NULL , Thread_TCP_Web_Send , NULL);

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TCP发送线程：

void * Thread_TCP_Web_Send(void *arg)
{
int len,j;
float cpu_temp;
while(1)
{
if(flag_keep_alive && flag_post_once)
{
flag_post_once = 0;
if(flag_get)
printf("收到客户端GET请求，服务器可进行一次POST操作\\n");
else if(flag_post)
printf("收到客户端POST回应，服务器可进行一次POST操作\\n");
File_Read_All_Text((char*)HTML_FILE);
len_buf_html=File_Read_Length((char*)HTML_FILE);
printf("\\n\\nHTML文件长度:len_buf_html=%d\\n\\n",len_buf_html);
//cpu_temp = Get_CPU_Temp();
cpu_temp = 37.7;
printf("\\n\\nCPU温度:%f\\n\\n",cpu_temp);
buf_html[143]=(int)(cpu_temp) / 10 % 10 + \'0\',
buf_html[144]=(int)(cpu_temp) % 10 + \'0\',
buf_html[146]=(int)(cpu_temp * 10) % 10 + \'0\';
buf_html[167]=(int)(dht11_temp) / 10 % 10 + \'0\',
buf_html[168]=(int)(dht11_temp) % 10 + \'0\';
buf_html[189]=(int)(dht11_humi) / 10 % 10 + \'0\',
buf_html[190]=(int)(dht11_humi) % 10 + \'0\';
//adc_value
buf_html[214]=(int)(adc_value) / 1000 % 10 + \'0\',
buf_html[215]=(int)(adc_value) / 100 %10 + \'0\';
buf_html[216]=(int)(adc_value) / 10 % 10 + \'0\',
buf_html[217]=(int)(adc_value) % 10 + \'0\';
a[31]=len_buf_html/10000%10+\'0\';
a[32]=len_buf_html/1000%10+\'0\';
a[33]=len_buf_html/100%10+\'0\';
a[34]=len_buf_html/10%10+\'0\';
a[35]=len_buf_html%10+\'0\';
for(len=0;a[len]!=\'\\0\';len++)
putchar(a[len]);
putchar(\'\\n\');
send(fd_socket_conn,a,len,0);
for(len=0;buf_html[len]!=\'\\0\';len++);
send(fd_socket_conn,buf_html,len,0);
free(buf_html);
close(fd_socket_conn);
}
/*
bzero(sendbuf,100);
scanf("%s",sendbuf);
if(sendbuf[0]==\'1\')
{
if(thread_flag==0)
{
thread_flag=1;
pthread_create(&id2,NULL,Thread_CPU_Temp,NULL);
if (pthread_mutex_init(&mut,NULL))
{
printf("互斥锁初始化失败\\n");
}
if (pthread_cond_init(&cond,NULL))
{
printf("cond初始化失败\\n");
}
}
}
else if(sendbuf[0]==\'2\')
{
thread_pause();
}
else if(sendbuf[0]==\'3\')
{
thread_resume();
}
*/
}
}

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TCP接收线程：

void * Thread_TCP_Web_Recv(void *arg)
{
int i,j;
while(1)
{
fd_socket_conn = accept(socket_web_server , (struct sockaddr *)&sockaddr_in_conn , &addrsize);
if(fd_socket_conn < 0)
{
printf("服务器接听失败!\\n");
flag_keep_alive = 0;
}
else if(fd_socket_conn >= 0)
{
printf("已有客户端成功连接服务器!\\n");
}
bzero(recvbuf,1000);
recv(fd_socket_conn,recvbuf,1000,0);
printf("------\\n%s\\n------\\n",recvbuf);
if(recvbuf[0]==\'G\'&&recvbuf[1]==\'E\'&&recvbuf[2]==\'T\')
{
printf("客户端浏览器发出GET请求\\n");
flag_get = 1;
flag_post = 0;
flag_post_once = 1;
}
if(recvbuf[0]==\'P\'&&recvbuf[1]==\'O\'&&recvbuf[2]==\'S\'&&recvbuf[3]==\'T\')
{
printf("客户端浏览器发出POST回应\\n");
flag_get = 0;
flag_post = 1;
flag_post_once = 1;
}
for(i = 0;i <= HTTP_GET_DEFAULT_LEN ; i ++)
{
if(recvbuf[i]==\'H\'&&recvbuf[i+1]==\'T\'&&recvbuf[i+2]==\'T\'&&recvbuf[i+3]==\'P\'&&
recvbuf[i+4]==\'/\')
{
printf("HTTP协议版本/类型：");
for(j=i;j<=i+7;j++)
putchar(recvbuf[j]);
putchar(\'\\n\');
}
if(recvbuf[i]==\'H\'&&recvbuf[i+1]==\'o\'&&recvbuf[i+2]==\'s\'&&recvbuf[i+3]==\'t\')
{
printf("主机地址及端口号：");
for(j=i+6;j<=i+22;j++)
putchar(recvbuf[j]);
putchar(\'\\n\');
}
if(recvbuf[i]==\'C\'&&recvbuf[i+1]==\'o\'&&recvbuf[i+2]==\'n\'&&recvbuf[i+3]==\'n\'&&
recvbuf[i+4]==\'e\'&&recvbuf[i+5]==\'c\'&&recvbuf[i+6]==\'t\'&&recvbuf[i+7]==\'i\'&&
recvbuf[i+8]==\'o\'&&recvbuf[i+9]==\'n\')
{
printf("连接方式：");
for(j=i+12;j<=i+21;j++)
putchar(recvbuf[j]);
putchar(\'\\n\');
flag_keep_alive = 1;
}
if(recvbuf[i]==\'l\'&&recvbuf[i+1]==\'e\'&&recvbuf[i+2]==\'d\'&&recvbuf[i+3]==\'_\'&&
recvbuf[i+4]==\'s\'&&recvbuf[i+5]==\'w\'&&recvbuf[i+6]==\'i\'&&recvbuf[i+7]==\'t\'&&
recvbuf[i+8]==\'c\'&&recvbuf[i+9]==\'h\'&&recvbuf[i+10]==\'=\')
{
printf("检测到LED控制指令:\\n");
if(recvbuf[i+11]==\'o\'&&recvbuf[i+12]==\'n\')
{
printf("LED开\\n");
//LED_Control(1);
}
else if(recvbuf[i+11]==\'o\'&&recvbuf[i+12]==\'f\'&&recvbuf[i+13]==\'f\')
{
printf("LED关\\n");
//LED_Control(0);
}
}
}
}
}

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Makefile：

PROG_UDP_IMAGE = udpimage
SRCS_UDP_IMAGE = main.cc camera.cc tcp_udp_app.cc lcd.cc hid.cc
CC = g++
CLEANFILES = $(PROG_MAIN)
INCLUDES ?=
CFLAGS += -ljpeg -lpthread -ludev
LDFLAGS ?=
all: $(PROG_UDP_IMAGE)
$(PROG_UDP_IMAGE): $(SRCS_UDP_IMAGE)
$(CC) -o $@ $^ $(CFLAGS) $(LDFLAGS) $(INCLUDES)
clean:
rm -f $(CLEANFILES)

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QT上位机应用程序：

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