[Python知识库]python学习 之 pyqt5前后端分离试验（热电偶温度读取）

1. 代码（假数据）

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *

from threading import Thread
import time, sys, os
import qdarkstyle

# 切换到当前目录
os.chdir(os.path.dirname(os.path.abspath(__file__)))

# 自定义信号源对象类型，一定要继承自 QObject
class MySignals(QObject):
    updateTempSingle = pyqtSignal(QProgressBar, float)


# 实例化
global_ms = MySignals()


class Temp_Gui(QWidget):

    def __init__(self):
        super(Temp_Gui, self).__init__()

        # 设置控件使用的字体为外部“./font/simkai.ttf”
        QFontDatabase.addApplicationFont("./font/simkai.ttf")
        # 设置字体大小

        font = QFont()
        font.setFamily("Arial")  # 括号里可以设置成自己想要的其它字体
        font.setPointSize(18)  # 括号里的数字可以设置成自己想要的字体大小
        QGroupBox("mywin").setFont(font)

        # 设置图标
        self.setWindowTitle("温度监测")
        self.setWindowIcon(QIcon('./images/boy.png'))
        self.resize(250, 100)

        StyleSheet = '''
        QWidget{
            text-align: center;
            border: 2px solid #2196F3;
            border-radius: 5px;
            background-color: #E0E0E0;
        },
        '''
        # 设置样式为红色
        # self.setStyleSheet(StyleSheet)
        self.setStyleSheet(qdarkstyle.load_stylesheet_pyqt5())

        formLayout = QFormLayout()

        self.Label_temp_name1 = QLabel('热电偶1:')
        self.Label_temp_name2 = QLabel('热电偶2:')
        self.Label_temp_name3 = QLabel('热电偶3:')

        self.LineEdit_temp_value1 = QLineEdit("0 °C")
        self.LineEdit_temp_value2 = QLineEdit("0 °C")
        self.LineEdit_temp_value3 = QLineEdit("0 °C")
        self.LineEdit_temp_value1.setReadOnly(True)
        self.LineEdit_temp_value2.setReadOnly(True)
        self.LineEdit_temp_value3.setReadOnly(True)
        # 设置字体居中
        self.LineEdit_temp_value1.setAlignment(Qt.AlignCenter)
        self.LineEdit_temp_value2.setAlignment(Qt.AlignCenter)
        self.LineEdit_temp_value3.setAlignment(Qt.AlignCenter)

        formLayout.addRow(self.Label_temp_name1, self.LineEdit_temp_value1)
        formLayout.addRow(self.Label_temp_name2, self.LineEdit_temp_value2)
        formLayout.addRow(self.Label_temp_name3, self.LineEdit_temp_value3)

        self.setLayout(formLayout)

        # 自定义信号的处理函数, 传出去给MySignals，再传回来给控件
        global_ms.updateTempSingle.connect(self.updataTemperature)

    def updataTemperature(self, object, value):
        object.setText(str(value) + " °C")


def readTempTask():
    def threadFunc():
        while True:
            # 使用a
            # 通过Signal 的 emit 触发执行 主线程里面的处理函数
            # emit参数和定义Signal的数量、类型必须一致
            for i in range(0, 101, 1):
                time.sleep(0.2)
                # 发出信号，通知主线程进行进度处理
                global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value1, i + 0.1 * i)
                global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value2, i + 0.2 * i)
                global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value3, i + 0.3 * i)

    thread = Thread(target=threadFunc, daemon=True)
    thread.start()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    temp_gui = Temp_Gui()
    temp_gui.show()
    readTempTask()
    sys.exit(app.exec_())

2. 代码（真数据）

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *

from threading import Thread
import time, sys, os
import qdarkstyle

import busio
import digitalio
import board
from adafruit_bus_device.spi_device import SPIDevice

# 切换到当前目录
os.chdir(os.path.dirname(os.path.abspath(__file__)))

# 自定义信号源对象类型，一定要继承自 QObject
class MySignals(QObject):
    updateTempSingle = pyqtSignal(QProgressBar, float)


# 实例化
global_ms = MySignals()


class Temp_Gui(QWidget):

    def __init__(self):
        super(Temp_Gui, self).__init__()

        # 设置控件使用的字体为外部“./font/simkai.ttf”
        QFontDatabase.addApplicationFont("./font/simkai.ttf")
        # 设置字体大小

        font = QFont()
        font.setFamily("Arial")  # 括号里可以设置成自己想要的其它字体
        font.setPointSize(18)  # 括号里的数字可以设置成自己想要的字体大小
        QGroupBox("mywin").setFont(font)

        # 设置图标
        self.setWindowTitle("温度监测")
        self.setWindowIcon(QIcon('./images/boy.png'))
        self.resize(250, 100)

        StyleSheet = '''
        QWidget{
            text-align: center;
            border: 2px solid #2196F3;
            border-radius: 5px;
            background-color: #E0E0E0;
        },
        '''
        # 设置样式为红色
        # self.setStyleSheet(StyleSheet)
        self.setStyleSheet(qdarkstyle.load_stylesheet_pyqt5())

        formLayout = QFormLayout()

        self.Label_temp_name1 = QLabel('热电偶1:')
        self.Label_temp_name2 = QLabel('热电偶2:')
        self.Label_temp_name3 = QLabel('热电偶3:')

        self.LineEdit_temp_value1 = QLineEdit("0 °C")
        self.LineEdit_temp_value2 = QLineEdit("0 °C")
        self.LineEdit_temp_value3 = QLineEdit("0 °C")
        self.LineEdit_temp_value1.setReadOnly(True)
        self.LineEdit_temp_value2.setReadOnly(True)
        self.LineEdit_temp_value3.setReadOnly(True)
        # 设置字体居中
        self.LineEdit_temp_value1.setAlignment(Qt.AlignCenter)
        self.LineEdit_temp_value2.setAlignment(Qt.AlignCenter)
        self.LineEdit_temp_value3.setAlignment(Qt.AlignCenter)

        formLayout.addRow(self.Label_temp_name1, self.LineEdit_temp_value1)
        formLayout.addRow(self.Label_temp_name2, self.LineEdit_temp_value2)
        formLayout.addRow(self.Label_temp_name3, self.LineEdit_temp_value3)

        self.setLayout(formLayout)

        # 自定义信号的处理函数, 传出去给MySignals，再传回来给控件
        global_ms.updateTempSingle.connect(self.updataTemperature)

    def updataTemperature(self, object, value):
        object.setText(str(value) + " °C")


def readTempTask():
    def threadFunc():
        # while True:
        #     # 使用a
        #     # 通过Signal 的 emit 触发执行 主线程里面的处理函数
        #     # emit参数和定义Signal的数量、类型必须一致
        #     for i in range(0, 101, 1):
        #         time.sleep(0.2)
        #         # 发出信号，通知主线程进行进度处理
        #         global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value1, i + 0.1 * i)
        #         global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value2, i + 0.2 * i)
        #         global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value3, i + 0.3 * i)
        with busio.SPI(board.SCLK, board.MOSI, board.MISO) as spi_bus:
            cs1_pin = digitalio.DigitalInOut(board.SPI1_CS)
            cs2_pin = digitalio.DigitalInOut(board.PC7)
            cs3_pin = digitalio.DigitalInOut(board.PC10)
            MAX6675_1 = SPIDevice(spi_bus, cs1_pin, baudrate=1_000_000)
            MAX6675_2 = SPIDevice(spi_bus, cs2_pin, baudrate=1_000_000)
            MAX6675_3 = SPIDevice(spi_bus, cs3_pin, baudrate=1_000_000)
            while True:
                bytes_read1 = bytearray(2)
                bytes_read2 = bytearray(2)
                bytes_read3 = bytearray(2)
                with MAX6675_1 as spi:
                    spi.readinto(bytes_read1)
                high_bit = bytes_read1[0] * 32
                low_bit = (bytes_read1[1] & 0b11111000) >> 3
                Temp1 = (high_bit + low_bit) * 0.25
                with MAX6675_2 as spi:
                    spi.readinto(bytes_read2)
                high_bit = bytes_read2[0] * 32
                low_bit = (bytes_read2[1] & 0b11111000) >> 3
                Temp2 = (high_bit + low_bit) * 0.25
                with MAX6675_3 as spi:
                    spi.readinto(bytes_read3)
                high_bit = bytes_read3[0] * 32
                low_bit = (bytes_read3[1] & 0b11111000) >> 3
                Temp3 = (high_bit + low_bit) * 0.25
                # print("Temperatures: %.2f C, %.2f C, %.2f C;" % (Temp1, Temp2, Temp3))
                # print("Temperatures: %.2f C;" % (Temp1))

                global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value1, Temp1)
                global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value2, Temp2)
                global_ms.updateTempSingle.emit(temp_gui.LineEdit_temp_value3, Temp3)

                # 注意MAX6675数据手册有说明，芯片的转换时间典型值为0.17s，最大值为0.22s
                time.sleep(0.22)

    thread = Thread(target=threadFunc, daemon=True)
    thread.start()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    temp_gui = Temp_Gui()
    temp_gui.show()
    readTempTask()
    sys.exit(app.exec_())

3. 运行图片