diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/arc/main.c b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/arc/main.c
new file mode 100644
index 00000000..f661b745
--- /dev/null
+++ b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/arc/main.c	
@@ -0,0 +1,194 @@
+#include "embARC_toolchain.h"
+#include "embARC_error.h"
+#include "dev_iic.h"
+#include "board.h"
+#define I2C_SLAVE_ADDR  0x48
+#define CHANNEL_0  0x40
+#define CHANNEL_1  0x41
+#define CHANNEL_2  0x42
+#define CHANNEL_3  0x43
+static DEV_GPIO_PTR port_ENA;
+static DEV_GPIO_PTR port_PUL; 
+static DEV_GPIO_PTR port_DIR;
+static void delay_ms(volatile int z)
+{
+	volatile uint32_t x,y;
+	for(x=1400;x>0;x--)
+		for(y=z;y>0;y--);
+}
+const char ad_channels[] = { CHANNEL_0, CHANNEL_1, CHANNEL_2, CHANNEL_3 };
+char write_buf[20];
+char read_buf[20];
+DEV_IIC *dev_iic0=NULL;
+static void position_init(void)
+{
+    dev_iic0 = iic_get_dev(DW_IIC_0_ID	);
+    dev_iic0->iic_open(DEV_MASTER_MODE, IIC_SPEED_STANDARD);
+	dev_iic0->iic_control(IIC_CMD_MST_SET_TAR_ADDR, CONV2VOID(I2C_SLAVE_ADDR));
+	port_ENA =  gpio_get_dev(DW_GPIO_PORT_C);  
+	port_ENA -> gpio_open(0x40000);
+	port_ENA -> gpio_control(GPIO_CMD_SET_BIT_DIR_OUTPUT, (void *)0x40000);
+	port_PUL =	gpio_get_dev(DW_GPIO_PORT_C);  
+	port_PUL -> gpio_open(0x10000); 
+	port_PUL -> gpio_control(GPIO_CMD_SET_BIT_DIR_OUTPUT, (void *)0x10000);
+	port_DIR =	gpio_get_dev(DW_GPIO_PORT_C);  
+	port_DIR -> gpio_open(0x20000); 
+	port_DIR -> gpio_control(GPIO_CMD_SET_BIT_DIR_OUTPUT, (void *)0x20000);
+	port_ENA -> gpio_write(0x00000, 0x40000);
+}
+static void laser_on(void)/*激光开启*/
+{
+	port_ENA -> gpio_write(0x40000, 0x40000);
+}
+static void laser_off(void)/*激光关闭*/
+{
+	port_ENA -> gpio_write(0x00000, 0x40000);
+}
+static void motor(void)/*电机移动*/
+{
+	int num=10;
+	while(num)
+	{
+		  port_PUL -> gpio_write(0x00000, 0x10000);
+		  delay_ms(80);	
+		  port_PUL -> gpio_write(0x10000, 0x10000);
+		  num--;
+		  delay_ms(80);		  
+	}
+}
+static void dir_near(void)/*纠正电机方向为近电机移动*/
+{
+	port_DIR -> gpio_write(0x20000, 0x20000);
+	delay_ms(100);
+	port_DIR -> gpio_write(0x00000, 0x20000);
+}
+static void dir_away(void)/*纠正电机方向为远电机移动*/
+{
+	port_DIR -> gpio_write(0x00000, 0x20000);
+	delay_ms(100);
+	port_DIR -> gpio_write(0x20000, 0x20000);
+}
+int main(void)
+{
+    unsigned int i;
+	unsigned int j;
+	unsigned int res;
+	char strbuf[256];
+	float adc[4];
+	float adc0;
+	float adc1;
+	float adc2;
+	float save [1][1000]={};
+	float ex [1][2000]={};
+	float d;
+	float e;
+	float f;
+	float g;
+	float h;
+	float k;
+	float m;
+	float o;
+	float p;
+	float q;	
+	int	N=1;
+	uint32_t rcv_cnt;
+	cpu_lock();
+	board_init();
+	position_init();
+while(1) 
+{
+	if(N%2==0)
+		{
+		laser_off();
+		}
+	else
+		{
+		laser_on();
+		}
+	printf("第N=%d次采样定位*************************************\r\n",N);
+	motor();
+	for (i = 0; i < 4; i++) 
+		 {
+          write_buf[0] = ad_channels[i];
+		  res = dev_iic0->iic_write(write_buf, 1);	
+	      rcv_cnt = dev_iic0->iic_read(read_buf, 2);	
+	      if(rcv_cnt)
+	       {
+				res = read_buf[0];
+			    res = ((res << 8) & 0xF0)| read_buf[1];
+				adc[i] = res;
+	        }
+		  }
+	      printf("Q1=%.3f,Q2=%.3f,Q3=%.3f,Q4=%.3f\r\n",adc[0]*3.3/255,
+	      adc[1]*3.3/255, adc[2]*3.3/255, adc[3]*3.3/255);
+	save [1][N] = adc[0]*3.3/255;
+	ex [1][N] = adc[1]*3.3/255;	
+	e=fabs((save [1][N])-(save [1][N-1]));/*第一象限Q1单差分的一次*/
+	f=fabs((save [1][N-1])-(save [1][N-2]));/*第一象限Q1单差分的二次*/
+	g=fabs((save [1][N-2])-(save [1][N-3]));/*第一象限Q1单差分的三次*/
+	o=fabs((save [1][N-3])-(save [1][N-4]));/*第一象限Q1单差分的四次*/	
+	h=fabs((ex [1][N])-(ex [1][N-1]));/*第二象限Q2单差分的一次*/
+	k=fabs((ex [1][N-1])-(ex [1][N-2]));/*第二象限Q2单差分的二次*/
+	m=fabs((ex [1][N-2])-(ex [1][N-3]));/*第二象限Q2单差分的三次*/
+	p=fabs((ex [1][N-3])-(ex [1][N-4]));/*第二象限Q2单差分的四次*/
+	printf("Q1一次差值=%.3f\r\n",e);
+	printf("Q1二次差值=%.3f\r\n",f);	
+	printf("Q1三次差值=%.3f\r\n",g);
+	printf("Q1四次差值=%.3f\r\n",o);		
+	printf("Q2一次差值=%.3f\r\n",h);
+	printf("Q2二次差值=%.3f\r\n",k);	
+	printf("Q2三次差值=%.3f\r\n",m);
+	printf("Q2四次差值=%.3f\r\n",p);	
+	q=0.013;/*根据外界环境预设定的双差分阈值，可变*/
+	if(e<q)/*双差分算法的各自四次判定*/
+	{
+	   	if(f<q)
+		{
+			if(g<q)
+			{
+				if(h<q)
+				{
+					if(k<q)
+					{
+						if(m<q)
+						{
+							if(o<q)
+							{
+								if(p<q)
+								{
+								delay_ms(1000);
+								port_ENA -> gpio_write(0x40000, 0x40000);/*激光常亮*/
+								printf("激光定位成功\r\n");								
+								break;
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	if(fabs((adc[0]*3.3/255-adc0))>0.05)/*Q1象限差分*/
+		{
+		 dir_away();
+		 printf("激光偏离，位于第一象限Q1\r\n");
+		}
+	if(fabs((adc[1]*3.3/255-adc1))>0.05)/*Q2象限差分*/
+		{
+		 dir_near();
+		 printf("激光偏离，位于第二象限Q2\r\n");
+		}
+	N++;
+	adc0=adc[0]*3.3/255;/*将第一象限输出电压值赋予变量，以作差分*/
+	adc1=adc[1]*3.3/255;/*将第二象限输出电压值赋予变量，以作差分*/
+}
+return E_SYS;	
+}
+			
+			
+			
+			
+			
+			
+			
+			
diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/arc/makefile b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/arc/makefile
new file mode 100644
index 00000000..19feed73
--- /dev/null
+++ b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/arc/makefile	
@@ -0,0 +1,60 @@
+# Application name
+APPL ?= example_tmpl
+
+# Optimization Level
+# Please Refer to toolchain_xxx.mk for this option
+OLEVEL ?= O2
+
+##
+# Current Board And Core
+##
+BOARD ?= emsk
+BD_VER ?= 22
+CUR_CORE ?= arcem7d
+TOOLCHAIN ?=gnu
+##
+# select debugging jtag
+##
+JTAG ?= usb
+
+##
+# Uncomment following options
+# if you want to set your own heap and stack size
+# Default settings see options.mk
+##
+#HEAPSZ ?= 8192
+#STACKSZ ?= 8192
+
+##
+# Uncomment following options
+# if you want to add your own library into link process
+# For example:
+# If you want link math lib for gnu toolchain,
+# you need to set the option to -lm
+##
+#APPL_LIBS ?=
+
+#
+# root dir of embARC
+#
+EMBARC_ROOT = ../../..
+
+MID_SEL = common
+
+# application source dirs
+APPL_CSRC_DIR = .
+APPL_ASMSRC_DIR = .
+
+# application include dirs
+APPL_INC_DIR = .
+
+# application defines
+APPL_DEFINES =
+
+# include current project makefile
+COMMON_COMPILE_PREREQUISITES += makefile
+
+### Options above must be added before include options.mk ###
+# include key embARC build system makefile
+override EMBARC_ROOT := $(strip $(subst \,/,$(EMBARC_ROOT)))
+include $(EMBARC_ROOT)/options/options.mk
diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/doc-ppt/Four-quadrant photoelectric sensor of laser positioning.pdf b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/doc-ppt/Four-quadrant photoelectric sensor of laser positioning.pdf
new file mode 100644
index 00000000..81ab2ea5
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diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/doc-ppt/Four-quadrant photoelectric sensor of laser positioning.pptx b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/doc-ppt/Four-quadrant photoelectric sensor of laser positioning.pptx
new file mode 100644
index 00000000..15bf3290
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diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/main(source-code).c b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/main(source-code).c
new file mode 100644
index 00000000..f661b745
--- /dev/null
+++ b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/main(source-code).c	
@@ -0,0 +1,194 @@
+#include "embARC_toolchain.h"
+#include "embARC_error.h"
+#include "dev_iic.h"
+#include "board.h"
+#define I2C_SLAVE_ADDR  0x48
+#define CHANNEL_0  0x40
+#define CHANNEL_1  0x41
+#define CHANNEL_2  0x42
+#define CHANNEL_3  0x43
+static DEV_GPIO_PTR port_ENA;
+static DEV_GPIO_PTR port_PUL; 
+static DEV_GPIO_PTR port_DIR;
+static void delay_ms(volatile int z)
+{
+	volatile uint32_t x,y;
+	for(x=1400;x>0;x--)
+		for(y=z;y>0;y--);
+}
+const char ad_channels[] = { CHANNEL_0, CHANNEL_1, CHANNEL_2, CHANNEL_3 };
+char write_buf[20];
+char read_buf[20];
+DEV_IIC *dev_iic0=NULL;
+static void position_init(void)
+{
+    dev_iic0 = iic_get_dev(DW_IIC_0_ID	);
+    dev_iic0->iic_open(DEV_MASTER_MODE, IIC_SPEED_STANDARD);
+	dev_iic0->iic_control(IIC_CMD_MST_SET_TAR_ADDR, CONV2VOID(I2C_SLAVE_ADDR));
+	port_ENA =  gpio_get_dev(DW_GPIO_PORT_C);  
+	port_ENA -> gpio_open(0x40000);
+	port_ENA -> gpio_control(GPIO_CMD_SET_BIT_DIR_OUTPUT, (void *)0x40000);
+	port_PUL =	gpio_get_dev(DW_GPIO_PORT_C);  
+	port_PUL -> gpio_open(0x10000); 
+	port_PUL -> gpio_control(GPIO_CMD_SET_BIT_DIR_OUTPUT, (void *)0x10000);
+	port_DIR =	gpio_get_dev(DW_GPIO_PORT_C);  
+	port_DIR -> gpio_open(0x20000); 
+	port_DIR -> gpio_control(GPIO_CMD_SET_BIT_DIR_OUTPUT, (void *)0x20000);
+	port_ENA -> gpio_write(0x00000, 0x40000);
+}
+static void laser_on(void)/*激光开启*/
+{
+	port_ENA -> gpio_write(0x40000, 0x40000);
+}
+static void laser_off(void)/*激光关闭*/
+{
+	port_ENA -> gpio_write(0x00000, 0x40000);
+}
+static void motor(void)/*电机移动*/
+{
+	int num=10;
+	while(num)
+	{
+		  port_PUL -> gpio_write(0x00000, 0x10000);
+		  delay_ms(80);	
+		  port_PUL -> gpio_write(0x10000, 0x10000);
+		  num--;
+		  delay_ms(80);		  
+	}
+}
+static void dir_near(void)/*纠正电机方向为近电机移动*/
+{
+	port_DIR -> gpio_write(0x20000, 0x20000);
+	delay_ms(100);
+	port_DIR -> gpio_write(0x00000, 0x20000);
+}
+static void dir_away(void)/*纠正电机方向为远电机移动*/
+{
+	port_DIR -> gpio_write(0x00000, 0x20000);
+	delay_ms(100);
+	port_DIR -> gpio_write(0x20000, 0x20000);
+}
+int main(void)
+{
+    unsigned int i;
+	unsigned int j;
+	unsigned int res;
+	char strbuf[256];
+	float adc[4];
+	float adc0;
+	float adc1;
+	float adc2;
+	float save [1][1000]={};
+	float ex [1][2000]={};
+	float d;
+	float e;
+	float f;
+	float g;
+	float h;
+	float k;
+	float m;
+	float o;
+	float p;
+	float q;	
+	int	N=1;
+	uint32_t rcv_cnt;
+	cpu_lock();
+	board_init();
+	position_init();
+while(1) 
+{
+	if(N%2==0)
+		{
+		laser_off();
+		}
+	else
+		{
+		laser_on();
+		}
+	printf("第N=%d次采样定位*************************************\r\n",N);
+	motor();
+	for (i = 0; i < 4; i++) 
+		 {
+          write_buf[0] = ad_channels[i];
+		  res = dev_iic0->iic_write(write_buf, 1);	
+	      rcv_cnt = dev_iic0->iic_read(read_buf, 2);	
+	      if(rcv_cnt)
+	       {
+				res = read_buf[0];
+			    res = ((res << 8) & 0xF0)| read_buf[1];
+				adc[i] = res;
+	        }
+		  }
+	      printf("Q1=%.3f,Q2=%.3f,Q3=%.3f,Q4=%.3f\r\n",adc[0]*3.3/255,
+	      adc[1]*3.3/255, adc[2]*3.3/255, adc[3]*3.3/255);
+	save [1][N] = adc[0]*3.3/255;
+	ex [1][N] = adc[1]*3.3/255;	
+	e=fabs((save [1][N])-(save [1][N-1]));/*第一象限Q1单差分的一次*/
+	f=fabs((save [1][N-1])-(save [1][N-2]));/*第一象限Q1单差分的二次*/
+	g=fabs((save [1][N-2])-(save [1][N-3]));/*第一象限Q1单差分的三次*/
+	o=fabs((save [1][N-3])-(save [1][N-4]));/*第一象限Q1单差分的四次*/	
+	h=fabs((ex [1][N])-(ex [1][N-1]));/*第二象限Q2单差分的一次*/
+	k=fabs((ex [1][N-1])-(ex [1][N-2]));/*第二象限Q2单差分的二次*/
+	m=fabs((ex [1][N-2])-(ex [1][N-3]));/*第二象限Q2单差分的三次*/
+	p=fabs((ex [1][N-3])-(ex [1][N-4]));/*第二象限Q2单差分的四次*/
+	printf("Q1一次差值=%.3f\r\n",e);
+	printf("Q1二次差值=%.3f\r\n",f);	
+	printf("Q1三次差值=%.3f\r\n",g);
+	printf("Q1四次差值=%.3f\r\n",o);		
+	printf("Q2一次差值=%.3f\r\n",h);
+	printf("Q2二次差值=%.3f\r\n",k);	
+	printf("Q2三次差值=%.3f\r\n",m);
+	printf("Q2四次差值=%.3f\r\n",p);	
+	q=0.013;/*根据外界环境预设定的双差分阈值，可变*/
+	if(e<q)/*双差分算法的各自四次判定*/
+	{
+	   	if(f<q)
+		{
+			if(g<q)
+			{
+				if(h<q)
+				{
+					if(k<q)
+					{
+						if(m<q)
+						{
+							if(o<q)
+							{
+								if(p<q)
+								{
+								delay_ms(1000);
+								port_ENA -> gpio_write(0x40000, 0x40000);/*激光常亮*/
+								printf("激光定位成功\r\n");								
+								break;
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	if(fabs((adc[0]*3.3/255-adc0))>0.05)/*Q1象限差分*/
+		{
+		 dir_away();
+		 printf("激光偏离，位于第一象限Q1\r\n");
+		}
+	if(fabs((adc[1]*3.3/255-adc1))>0.05)/*Q2象限差分*/
+		{
+		 dir_near();
+		 printf("激光偏离，位于第二象限Q2\r\n");
+		}
+	N++;
+	adc0=adc[0]*3.3/255;/*将第一象限输出电压值赋予变量，以作差分*/
+	adc1=adc[1]*3.3/255;/*将第二象限输出电压值赋予变量，以作差分*/
+}
+return E_SYS;	
+}
+			
+			
+			
+			
+			
+			
+			
+			
diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/project-picture/Circuit-interconnection-diagram.png b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/project-picture/Circuit-interconnection-diagram.png
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diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/project-picture/System-physical-map.png b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/project-picture/System-physical-map.png
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diff --git a/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/summary.pdf b/arc_design_contest/2019/XDU_Four-quadrant photoelectric sensor of laser positioning/summary.pdf
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