Raspberry pi zero w Matplotlib绘图问题

Question

我正试图读取距离数据从Camsense X1激光雷达与覆盆子皮零w。我能够获得距离数据，但问题开始于绘图方面。Matplotlib绘制初始数据，但不更新图形。我尝试了为这个传感器编写的其他脚本，但结果是一样的

脚本源：https://memotut.com/en/819aced4d48efd97c79f/

其他脚本：

https://github.com/Takahiro55555/camsenseX1-operation-test/blob/master/src/capture.pyhttps://github.com/Vidicon/camsense-X1

import matplotlib.pyplot as plt
import math
import serial
import sys
import struct
import time
import threading

class Capture:
def __init__(self, serialPort, dataSize = 460, isInvert = True):
    self.theta = [0] * dataSize
    self.distance = [0] * dataSize
    self.intensity = [0] * dataSize
    self.writePos = 0
    self.serial = serial.Serial(port = serialPort, baudrate = 115200)
    self.dataSize = dataSize
    self.thread = threading.Thread(target = self.getData)
    self.lock = threading.Lock()
    self.isInvert = isInvert
    self.dataObtained = False
    self.rpm = 0

def getDataUnit(self):
    #First, read down to the header
    header = b"\x55\xAA\x03\x08"
    headerPos = 0
    while True:
        tmp = self.serial.read(1)
        if tmp[0] == header[headerPos]:
            headerPos += 1
            if headerPos == len(header):
                break
        else:
            headerPos = 0

    tmp = self.serial.read(4)
    # "<" :Little endian, "H" :2-byte unsigned data, "B" :1-byte unsigned data
    (rotationSpeedTmp, startAngleTmp) = struct.unpack_from("<2H", tmp)
    self.rpm = rotationSpeedTmp / 64
    startAngle = (startAngleTmp - 0xa000) / 64
    #Prepare an array to store distance and intensity data
    distanceTmp = [0] * 8
    intensityTmp = [0] * 8
    for i in range(8):
        tmp = self.serial.read(3)
        (distanceTmp[i], intensityTmp[i]) = struct.unpack_from("<HB", tmp)
    tmp = self.serial.read(4)
    (endAngleTmp, crc) = struct.unpack_from("<2H", tmp)
    endAngle = (endAngleTmp - 0xa000) / 64

    return (distanceTmp, intensityTmp, startAngle, endAngle)

def getData(self):
    preStartAngle = 0
    while True:
        (distanceTmp, intensityTmp, startAngle, endAngle) = self.getDataUnit()

       
        if endAngle < startAngle:
            endAngle += 360

        #When the start angle becomes small, it is a place of 0 degrees, so set the data update flag
        if (startAngle - preStartAngle < 0):
            self.dataObtained = True
        preStartAngle = startAngle

        #Convert angles to radians
        startAngleRad = startAngle * math.pi / 180 * (-1 if self.isInvert else 1)
        endAngleRad = endAngle * math.pi / 180 * (-1 if self.isInvert else 1)
        #Calculate the angle per step
        angleIncrement = (endAngleRad - startAngleRad) / len(distanceTmp)
        #Exclusive control start
        self.lock.acquire()
        for i in range(len(distanceTmp)):
            self.theta[self.writePos] = startAngleRad + angleIncrement * i
            self.distance[self.writePos] = distanceTmp[i]
            self.intensity[self.writePos] = intensityTmp[i]
            self.writePos += 1
            if self.writePos >= self.dataSize:
                self.writePos = 0
        #Exclusive control end
        self.lock.release()

def run(self):
    self.thread.start()

def stop(self):
    self.thread.stop()

   if __name__ == "__main__":
if len(sys.argv) == 1:
    print("You must specify serial port! ex) " + sys.argv[0] + " COM2")
    quit()

#Generate polar graph
dist = plt.subplot(111, polar = True)
#Set the initial value of the maximum distance to be displayed to 2000
rmax = 2000

capture = Capture(sys.argv[1], dataSize = 480, isInvert = True)
capture.run()
preTime = time.time()

while True:
    if capture.dataObtained:
        #Initialize drawing
        plt.cla()

        #Exclusive control start
        capture.lock.acquire()
        #Plot distance data(Draw as a scatter plot)
        dist.scatter(list(capture.theta), list(capture.distance), c = "blue", s = 5)
        #Plot intensity data(Draw by connecting with lines)
        dist.plot(list(capture.theta), list(capture.intensity), c = "orange", linewidth = 1)
        #Since the data has been drawn, lower the data acquisition flag.
        capture.dataObtained = False
        #Exclusive control start
        capture.lock.release()

        #Set the top of the screen to 0 degrees
        dist.set_theta_offset(math.pi / 2)
        #Set the maximum value of the distance value to be displayed
        dist.set_rmax(rmax)
        #Drawing process
        plt.pause(0.01)
        #Get the currently set maximum display distance value
        rmax = dist.get_rmax()

    else:
        time.sleep(0.01)

绘图：