有人能帮忙看下么

THRESHOLD = ((24, 97, -25, 100, -128, 127)) # Grayscale threshold for dark things...
import sensor, image, time
from pyb import LED
from pid import PID
from pyb import UART
rho_pid = PID(p=0.4, i=0)
theta_pid = PID(p=0.08, i=0)
uart = UART(3, 9600)

LED(1).on()
LED(2).on()
LED(3).on()

sensor.reset()
sensor.set_vflip(True)
sensor.set_hmirror(True)
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQQVGA) # 80x60 (4,800 pixels) - O(N^2) max = 2,3040,000.
#sensor.set_windowing([0,20,80,40])
sensor.skip_frames(time = 2000)     # WARNING: If you use QQVGA it may take seconds
clock = time.clock()                # to process a frame sometimes.

while(True):
    clock.tick()
    img = sensor.snapshot().binary([THRESHOLD])
    line = img.get_regression([(100,100,0,0,0,0)], robust = True)#返回一条直线对象
    if (line):
        rho_err = abs(line.rho())-img.width()/2     #直线左右偏移距离，需要调整到视野中央
        if line.theta()>90:
            theta_err = line.theta()-180            #与y轴平行的方向，即0°
        else:
            theta_err = line.theta()
        print(theta_err)
        #FH = bytearray([0xb3,0xb3])
        #uart.write(FH)
        uart.write((str(theta_err)))
      
   

下面是51单片机的接受代码

#include "reg52.h"
typedef unsigned int u16;
typedef unsigned char u8;
static u8 Temp;  					//定义临时变量
static u16 a; 
sbit led1=P2^0;
sbit led2=P2^1;
sbit led3=P2^2;

void UsartInit()
{
	TMOD=0X20;
	SCON=0X50;
	TH1=0XFD;
	TL1=TH1;
	PCON=0X00;
	TR1=1;	
	ES=1;
	EA=1;
}						   
void main()
{
	UsartInit();
	while(1)
	{
			 	
	}
}
/*------------------------------------------------
                    发送一个字节
------------------------------------------------*/
void SendByte(unsigned char dat)
{
 SBUF = dat;
 while(!TI);
      TI = 0;
}
/*------------------------------------------------
                    发送一个字符串
------------------------------------------------*/
void SendStr(unsigned char *s)
{
 while(*s!='\0')// \0 表示字符串结束标志，通过检测是否字符串末尾
  {
  SendByte(*s);
  s++;
  }
}

void Usart() interrupt 4
{   
	if(RI)                        //判断是接收中断产生
	{	
		RI=0;                      //标志位清零
		Temp=SBUF;
		a=SBUF;                 

		if(-6<a<3)
			{
				led2=0;
			}
		if(a<=-6)
			{
				led1=0;
				
			}			  
		else
			{
				led3=0;						
			}
	
			     	
	}
	else
	{
		TI=0;
	}
}