I am creating a PyQt5 parking detection warning system with a Rasberry Pi and HC-SR04 distance sensor as part of a go-kart dashboard project. I am trying to update some polygon png images (QImage) from an "ON" state to an "OFF" state if a certain distance is met, hence I am running it in a thread While-loop.
To achieve this I have an if-statement, allowing the program to set a Pixmap for the label that will hold each polygon and update it with the ON/OFF version of the image depending on the distance. However, once I keep the program running for around 20 seconds, it closes and gives me a "segmentation fault" error.
For reference, there are 12 polygons images for detecting the distance from the front of the kart (4 vertical polygons for each sensor x 3), and so far I have only tried implementing the first four (named "front_1a", "front_1b", "front_1c", and "front_1d" accordingly.
Distance sensor thread function:
def update_sensors(self):
sensor = DistanceSensor(24, 23)
min_dist = 2
max_dist = 100
self.dist_step_01 = min_dist + round((max_dist - min_dist) / 4 * 1)
self.dist_step_02 = min_dist + round((max_dist - min_dist) / 4 * 2)#0.1425
self.dist_step_03 = min_dist + round((max_dist - min_dist) / 4 * 3)
self.dist_step_04 = min_dist + round((max_dist - min_dist) / 4 * 4)
print(self.dist_step_01)
while self.update_sensors_started:
total_distance = round(sensor.distance*100)
self.front_1a_Label.setPixmap(self.front_1a_ON if total_distance < self.dist_step_01 else self.front_1a_OFF)
self.front_1b_Label.setPixmap(self.front_1b_ON if total_distance < self.dist_step_02 else self.front_1b_OFF)
self.front_1c_Label.setPixmap(self.front_1c_ON if total_distance < self.dist_step_03 else self.front_1c_OFF)
self.front_1d_Label.setPixmap(self.front_1d_ON if total_distance < self.dist_step_04 else self.front_1d_OFF)
print('Distance to nearest object is', total_distance, 'cm')
sleep(0.5)
Full project code:
import cv2
import csv
from imutils.video import VideoStream
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtGui import QPixmap
import gpsd
import vlc
from threading import Thread
import time
from datetime import datetime
import subprocess
from gpiozero import DistanceSensor
from time import sleep
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
self.setup_fonts()
self.setup_window(MainWindow)
self.setup_dashboard_tab(MainWindow)
self.setup_camera_tab(MainWindow)
self.setup_media_tab(MainWindow)
self.initialize_ui(MainWindow)
# Launch the GUI with Tab 1 selected
self.tabWidget.setCurrentIndex(1)
self.play_startup_sound()
def setup_fonts(self):
# Setup font database
QtGui.QFontDatabase.addApplicationFont("fonts/RIDGE-LIGHT-OBLIQUE.otf")
QtGui.QFontDatabase.addApplicationFont("fonts/Ridge-Bold-Oblique.otf")
self.light_30_font = QtGui.QFont("RIDGE-LIGHT-OBLIQUE", 30)
self.light_20_font = QtGui.QFont("RIDGE-LIGHT-OBLIQUE", 20)
self.speed_font = QtGui.QFont("Ridge-Bold-Oblique", 120)
def setup_window(self, MainWindow):
# Set up the main window
MainWindow.setObjectName("MainWindow")
MainWindow.resize(1024, 600)
MainWindow.setMinimumSize(QtCore.QSize(1024, 600))
MainWindow.setMaximumSize(QtCore.QSize(1024, 600))
MainWindow.setTabletTracking(True)
MainWindow.setStyleSheet("background-color: rgb(9, 8, 4);")
# Set up the central widget (main container)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
# Set up tab widget
self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
self.tabWidget.setGeometry(QtCore.QRect(-10, -30, 1041, 631))
self.tabWidget.setObjectName("tabWidget")
# General setup
MainWindow.setCentralWidget(self.centralwidget)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def setup_dashboard_tab(self, MainWindow):
# Setting up Tab 1: Main dashboard
self.mainDash = QtWidgets.QWidget()
self.mainDash.setObjectName("mainDash")
self.tabWidget.addTab(self.mainDash, "")
# Location label
self.locationLabel = QtWidgets.QLabel(self.mainDash)
self.locationLabel.setGeometry(QtCore.QRect(80, 430, 231, 51))
self.locationLabel.setFont(self.light_30_font)
self.locationLabel.setStyleSheet("color:#464646;")
self.locationLabel.setAlignment(QtCore.Qt.AlignCenter)
self.locationLabel.setObjectName("locationLabel")
self.locationValueLabel = QtWidgets.QLabel(self.mainDash)
self.locationValueLabel.setGeometry(QtCore.QRect(10, 480, 371, 41))
self.locationValueLabel.setFont(self.light_20_font)
self.locationValueLabel.setStyleSheet("color: rgb(255, 255, 255);")
self.locationValueLabel.setAlignment(QtCore.Qt.AlignCenter)
self.locationValueLabel.setObjectName("locationValueLabel")
# Outside temperature label
self.outTempLabel = QtWidgets.QLabel(self.mainDash)
self.outTempLabel.setGeometry(QtCore.QRect(730, 430, 231, 51))
self.outTempLabel.setFont(self.light_30_font)
self.outTempLabel.setStyleSheet("color:#464646;")
self.outTempLabel.setAlignment(QtCore.Qt.AlignCenter)
self.outTempLabel.setObjectName("outTempLabel")
self.outTempValLabel = QtWidgets.QLabel(self.mainDash)
self.outTempValLabel.setGeometry(QtCore.QRect(650, 480, 381, 41))
self.outTempValLabel.setFont(self.light_20_font)
self.outTempValLabel.setStyleSheet("color: rgb(255, 255, 255);")
self.outTempValLabel.setAlignment(QtCore.Qt.AlignCenter)
self.outTempValLabel.setObjectName("outTempValLabel")
# Speedometer
self.speedLabel = QtWidgets.QLabel(self.mainDash)
self.speedLabel.setGeometry(QtCore.QRect(390, 155, 251, 171))
self.speedLabel.setFont(self.speed_font)
self.speedLabel.setStyleSheet("color: rgb(255, 255, 255);")
self.speedLabel.setAlignment(QtCore.Qt.AlignCenter)
self.speedLabel.setObjectName("speedLabel")
self.speedCircle = QtWidgets.QFrame(self.mainDash)
self.speedCircle.setGeometry(QtCore.QRect(360, 110, 311, 311))
self.speedCircle.setStyleSheet("QFrame{\n"
" border: 5px solid rgb(1, 203, 238);\n"
" background-color: none;\n"
" border-radius: 150px;\n"
"}")
self.speedCircle.setFrameShape(QtWidgets.QFrame.StyledPanel)
self.speedCircle.setFrameShadow(QtWidgets.QFrame.Raised)
self.speedCircle.setObjectName("speedCircle")
self.kmhLabel = QtWidgets.QLabel(self.mainDash)
self.kmhLabel.setGeometry(QtCore.QRect(470, 300, 91, 51))
self.kmhLabel.setFont(self.light_30_font)
self.kmhLabel.setStyleSheet("color:white;")
self.kmhLabel.setAlignment(QtCore.Qt.AlignCenter)
self.kmhLabel.setObjectName("kmhLabel")
self.timeLabel = QtWidgets.QLabel(self.mainDash)
self.timeLabel.setGeometry(QtCore.QRect(410, 0, 211, 71))
# Time label
self.timeLabel.setFont(self.light_30_font)
self.timeLabel.setStyleSheet("color: rgb(255, 255, 255);")
self.timeLabel.setAlignment(QtCore.Qt.AlignCenter)
self.timeLabel.setObjectName("timeLabel")
def setup_camera_tab(self, MainWindow):
# Setting up Tab 2: Camera View
self.cameraView = QtWidgets.QWidget()
self.cameraView.setObjectName("cameraView")
#self.cameraFrame = QtWidgets.QLabel(self.cameraView)
#self.cameraFrame.setStyleSheet("background-color: lightgreen")
#self.cameraFrame.setGeometry(QtCore.QRect(0, 0, 1024, 600))
#self.cameraFrame.setObjectName("cameraFrame")
self.bgLabel = QtWidgets.QLabel(MainWindow)
self.bgLabel.setStyleSheet("background-color: lightgreen")
self.bgLabel.setGeometry(QtCore.QRect(0, 0, 1024, 600))
self.bgLabel.setFrameShape(QtWidgets.QFrame.Box)
self.bgLabel.setLineWidth(3)
self.bgLabel.setText("")
self.bgLabel.setObjectName("bgLabel")
self.overlayLabel = QtWidgets.QLabel(MainWindow)
self.overlayLabel.setGeometry(QtCore.QRect(0, 0, 1024, 600))
self.overlayLabel.setFrameShape(QtWidgets.QFrame.Box)
self.overlayLabel.setLineWidth(3)
self.overlayLabel.setText("")
self.overlayLabel.setObjectName("overlayLabel")
self.overlayLabel.setStyleSheet("background:transparent;")
self.centerLabel = QtWidgets.QLabel(MainWindow)
self.centerLabel.setGeometry(QtCore.QRect(822, 105, 122, 160))
self.centerLabel.setFrameShape(QtWidgets.QFrame.Box)
self.centerLabel.setText("")
self.centerLabel.setObjectName("centerLabel")
self.centerLabel.setStyleSheet("background:transparent;")
self.front_1a_Label = QtWidgets.QLabel(MainWindow)
self.front_1a_Label.setGeometry(QtCore.QRect(819, 93, 44, 32))
self.front_1a_Label.setText("")
self.front_1a_Label.setObjectName("front_1a_Label")
self.front_1a_Label.setStyleSheet("background:transparent;")
self.front_1b_Label = QtWidgets.QLabel(MainWindow)
self.front_1b_Label.setGeometry(QtCore.QRect(804, 72, 55, 43))
self.front_1b_Label.setText("")
self.front_1b_Label.setObjectName("front_1b_Label")
self.front_1b_Label.setStyleSheet("background:transparent;")
self.front_1c_Label = QtWidgets.QLabel(MainWindow)
self.front_1c_Label.setGeometry(QtCore.QRect(789, 51, 65, 48))
self.front_1c_Label.setText("")
self.front_1c_Label.setObjectName("front_1c_Label")
self.front_1c_Label.setStyleSheet("background:transparent;")
self.front_1d_Label = QtWidgets.QLabel(MainWindow)
self.front_1d_Label.setGeometry(QtCore.QRect(774, 30, 74, 54))
self.front_1d_Label.setText("")
self.front_1d_Label.setObjectName("front_1d_Label")
self.front_1d_Label.setStyleSheet("background:transparent;")
self.front_2a_Label = QtWidgets.QLabel(MainWindow)
self.front_2a_Label.setGeometry(QtCore.QRect(860, 89, 46, 16))
self.front_2a_Label.setText("")
self.front_2a_Label.setObjectName("front_2a_Label")
self.front_2a_Label.setStyleSheet("background:transparent;")
self.front_2b_Label = QtWidgets.QLabel(MainWindow)
self.front_2b_Label.setGeometry(QtCore.QRect(855, 68, 56, 23))
self.front_2b_Label.setText("")
self.front_2b_Label.setObjectName("front_2b_Label")
self.front_2b_Label.setStyleSheet("background:transparent;")
self.front_2c_Label = QtWidgets.QLabel(MainWindow)
self.front_2c_Label.setGeometry(QtCore.QRect(849, 46, 67, 24))
self.front_2c_Label.setText("")
self.front_2c_Label.setObjectName("front_2c_Label")
self.front_2c_Label.setStyleSheet("background:transparent;")
self.front_2d_Label = QtWidgets.QLabel(MainWindow)
self.front_2d_Label.setGeometry(QtCore.QRect(844, 25, 78, 24))
self.front_2d_Label.setText("")
self.front_2d_Label.setObjectName("front_2d_Label")
self.front_2d_Label.setStyleSheet("background:transparent;")
self.front_3a_Label = QtWidgets.QLabel(MainWindow)
self.front_3a_Label.setGeometry(QtCore.QRect(903, 92, 44, 32))
self.front_3a_Label.setText("")
self.front_3a_Label.setObjectName("front_3a_Label")
self.front_3a_Label.setStyleSheet("background:transparent;")
self.front_3b_Label = QtWidgets.QLabel(MainWindow)
self.front_3b_Label.setGeometry(QtCore.QRect(907, 72, 55, 43))
self.front_3b_Label.setText("")
self.front_3b_Label.setObjectName("front_3b_Label")
self.front_3b_Label.setStyleSheet("background:transparent;")
self.front_3c_Label = QtWidgets.QLabel(MainWindow)
self.front_3c_Label.setGeometry(QtCore.QRect(912, 51, 65, 48))
self.front_3c_Label.setText("")
self.front_3c_Label.setObjectName("front_3c_Label")
self.front_3c_Label.setStyleSheet("background:transparent;")
self.front_3d_Label = QtWidgets.QLabel(MainWindow)
self.front_3d_Label.setGeometry(QtCore.QRect(918, 30, 74, 54))
self.front_3d_Label.setText("")
self.front_3d_Label.setObjectName("front_3d_Label")
self.front_3d_Label.setStyleSheet("background:transparent;")
self.overlay = QPixmap("graphics/parking_overlay.png")
self.center = QPixmap("graphics/go_kart_center.png")
self.front_1a_ON = QPixmap("graphics/front_1a_ON.png")
self.front_1b_ON = QPixmap("graphics/front_1b_ON.png")
self.front_1c_ON = QPixmap("graphics/front_1c_ON.png")
self.front_1d_ON = QPixmap("graphics/front_1d_ON.png")
self.front_1a_OFF = QPixmap("graphics/front_1a_OFF.png")
self.front_1b_OFF = QPixmap("graphics/front_1b_OFF.png")
self.front_1c_OFF = QPixmap("graphics/front_1c_OFF.png")
self.front_1d_OFF = QPixmap("graphics/front_1d_OFF.png")
self.front_2a_ON = QPixmap("graphics/front_2a_ON.png")
self.front_2b_ON = QPixmap("graphics/front_2b_ON.png")
self.front_2c_ON = QPixmap("graphics/front_2c_ON.png")
self.front_2d_ON = QPixmap("graphics/front_2d_ON.png")
self.front_2a_OFF = QPixmap("graphics/front_2a_OFF.png")
self.front_2b_OFF = QPixmap("graphics/front_2b_OFF.png")
self.front_2c_OFF = QPixmap("graphics/front_2c_OFF.png")
self.front_2d_OFF = QPixmap("graphics/front_2d_OFF.png")
self.front_3a_ON = QPixmap("graphics/front_3a_ON.png")
self.front_3b_ON = QPixmap("graphics/front_3b_ON.png")
self.front_3c_ON = QPixmap("graphics/front_3c_ON.png")
self.front_3d_ON = QPixmap("graphics/front_3d_ON.png")
self.front_3a_OFF = QPixmap("graphics/front_3a_OFF.png")
self.front_3b_OFF = QPixmap("graphics/front_3b_OFF.png")
self.front_3c_OFF = QPixmap("graphics/front_3c_OFF.png")
self.front_3d_OFF = QPixmap("graphics/front_3d_OFF.png")
self.overlayLabel.setPixmap(self.overlay)
self.centerLabel.setPixmap(self.center)
vboxTab1 = QtWidgets.QGridLayout()
vboxTab1.addWidget(self.bgLabel)
vboxTab1.addWidget(self.overlayLabel, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.centerLabel, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_1a_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_1b_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_1c_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_1d_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_2a_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_2b_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_2c_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_2d_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_3a_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_3b_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_3c_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
vboxTab1.addWidget(self.front_3d_Label, 0,0,1,1, QtCore.Qt.AlignHCenter)
self.cameraView.setLayout(vboxTab1)
self.tabWidget.addTab(self.cameraView, "")
def setup_media_tab(self, MainWindow):
pass
def initialize_ui(self, MainWindow):
"""
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "Dashboard"))
self.speedLabel.setText(_translate("MainWindow", "37"))
self.kmhLabel.setText(_translate("MainWindow", "KMH"))
self.timeLabel.setText(_translate("MainWindow", "8:36 PM"))
self.locationValueLabel.setText(_translate("MainWindow", "SOME STREET"))
"""
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "Dashboard"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.mainDash), _translate("MainWindow", "Main Dash"))
#self.cameraFrame.setText(_translate("MainWindow", "TextLabel"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.cameraView), _translate("MainWindow", "Camera View"))
self.locationLabel.setText(_translate("MainWindow", "LOCATION"))
self.outTempLabel.setText(_translate("MainWindow", "OUT TEMP"))
self.kmhLabel.setText(_translate("MainWindow", "KMH"))
self.outTempValLabel.setText(_translate("MainWindow", "+ 25 C"))
# Update speed every second
self.speed_thread = Thread(target=self.update_speed)
self.initialize_gps()
# Update location every 10 seconds
self.location_thread = Thread(target=self.update_location)
self.initialize_location_csv()
# Update time every second
self.time_thread = Thread(target=self.update_time)
# Update camera
self.camera_thread = Thread(target=self.update_camera)
#Update sensors
self.sensors_thread = Thread(target=self.update_sensors)
self.update_speed_started = True
self.update_location_started = True
self.update_time_started = True
self.update_camera_started = True
self.update_sensors_started = True
self.speed_thread.start()
self.location_thread.start()
self.time_thread.start()
self.camera_thread.start()
self.sensors_thread.start()
def play_startup_sound(self):
player = vlc.MediaPlayer("sounds/startup_chime.mp3")
player.play()
def initialize_gps(self):
print("Initializing GPS...")
# TODO: Check for GPS status
subprocess.run(["systemctl", "enable", "gpsd.socket"])
gpsd.connect()
def initialize_location_csv(self):
print("Creating connection to location csv...")
search_file = open('csv/canadacities.csv', 'r')
self.location_reader = csv.reader(search_file, delimiter= ',')
self.location_dict = {}
for city in self.location_reader:
if city[0] != 'city':
self.location_dict[city[0]] = (float(city[4]), float(city[5]))
def get_time(self):
"""
# Get gps packet
gps_packet = gpsd.get_current()
# Extract time
date_time = str(gps_packet.time)
split_list = date_time.split("T")
gps_time = split_list[1]
hour_minute = gps_time.split(":")
hour = hour_minute[0]
minute = hour_minute[1]
return f"{hour}:{minute} {'PM' if int(hour) > 11 else 'AM'}"
"""
now = datetime.now()
military_hour = now.strftime("%H")
hour = (int(military_hour) - 2) % 10
minute = now.strftime("%M")
return f"{hour}:{minute} {'PM' if int(military_hour) > 11 else 'AM'}"
def get_speed(self):
# Get gps packet
gps_packet = gpsd.get_current()
# Extract speed
speed_mph = float(gps_packet.hspeed)
# Convert speed to int and kmh
speed_kmh_int = int(speed_mph * 1.609344)
print(f"Current speed: {speed_kmh_int}")
return speed_kmh_int
def get_current_suberb(self):
# Get gps packet
gps_packet = gpsd.get_current()
# Get latitude and longitude
lat = gps_packet.lat
long = gps_packet.lon
print(f"My coordinates: {lat}, {long}")
curr_match = 100.00
matched_city = ""
# Search through location csv
for city in self.location_dict:
city_lat = self.location_dict[city][0]
city_long = self.location_dict[city][1]
lat_diff = abs(lat) - abs(city_lat)
long_diff = abs(long) - abs(city_long)
calc_match = abs(lat_diff) + abs(long_diff)
if calc_match < curr_match:
curr_match = calc_match
matched_city = str(city)
print(f"Matched city: {matched_city}")
return matched_city
def update_speed(self):
while self.update_speed_started:
# Set current speed
self.speedLabel.setText(str(self.get_speed()))
time.sleep(1)
def update_location(self):
while self.update_location_started:
# Set current suburb
self.locationValueLabel.setText(self.get_current_suberb())
time.sleep(5)
def update_time(self):
while self.update_time_started:
# Set current time
self.timeLabel.setText(self.get_time())
time.sleep(1)
def update_camera(self):
usingPiCamera = True
frameSize = (1024, 600)
vs = VideoStream(src=0, usePiCamera=usingPiCamera, resolution=frameSize, framerate=32).start()
time.sleep(0.5)
while self.update_camera_started:
self.frame = vs.read()
self.image = QtGui.QImage(self.frame.data, self.frame.shape[1], self.frame.shape[0], QtGui.QImage.Format_RGB888).rgbSwapped()
time.sleep(0.1)
self.bgLabel.setPixmap(QPixmap.fromImage(self.image))
cv2.destroyAllWindows()
vs.stop()
def update_sensors(self):
sensor = DistanceSensor(24, 23)
min_dist = 2
max_dist = 100
self.dist_step_01 = min_dist + round((max_dist - min_dist) / 4 * 1)
self.dist_step_02 = min_dist + round((max_dist - min_dist) / 4 * 2)#0.1425
self.dist_step_03 = min_dist + round((max_dist - min_dist) / 4 * 3)
self.dist_step_04 = min_dist + round((max_dist - min_dist) / 4 * 4)
print(self.dist_step_01)
while self.update_sensors_started:
total_distance = round(sensor.distance*100)
self.front_1a_Label.setPixmap(self.front_1a_ON if total_distance < self.dist_step_01 else self.front_1a_OFF)
self.front_1b_Label.setPixmap(self.front_1b_ON if total_distance < self.dist_step_02 else self.front_1b_OFF)
self.front_1c_Label.setPixmap(self.front_1c_ON if total_distance < self.dist_step_03 else self.front_1c_OFF)
self.front_1d_Label.setPixmap(self.front_1d_ON if total_distance < self.dist_step_04 else self.front_1d_OFF)
print('Distance to nearest object is', total_distance, 'cm')
sleep(0.5)
def stop(self):
print("Exiting...")
self.update_location_started = False
self.update_speed_started = False
self.update_time_started = False
self.update_camera_started = False
self.update_sensors_started = False
self.speed_thread.join()
self.time_thread.join()
self.camera_thread.join()
self.sensors_thread.join()
self.location_thread.join()
From removing/adding certain parts of the thread function, I figured out that it is the action of setting the QPixmap that is causing the segmentation fault error.
