"""
This example demonstrates many of the 2D plotting capabilities
in pyqtgraph. All of the plots may be panned/scaled by dragging with 
the left/right mouse buttons. Right click on any plot to show a context menu.
"""
import serial, struct
import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore

if __name__ == '__main__':

    ser = serial.Serial("COM2", 115200, timeout=250)    # 打开COM17，将波特率配置为115200，其余参数使用默认值
    if ser.isOpen():                        # 判断串口是否成功打开
        print("打开串口成功。")
        # print(ser.name)    # 输出串口号
    else:
        print("打开串口失败。")

    app = pg.mkQApp("Plotting Example")
    #mw = QtWidgets.QMainwin1dow()
    #mw.resize(800,800)
    win1 = pg.GraphicsLayoutWidget(show=True, title="Basic plotting examples")
    win1.resize(1000,600)
    win1.setWindowTitle('pyqtgraph example: Plotting1')

    # Enable antialiasing for prettier plots
    pg.setConfigOptions(antialias=True)
    win1.nextRow()
    win1.nextCol()
    p6 = win1.addPlot(title="Updating plot")
    curve = p6.plot(pen=None, symbolBrush=(255,0,0), symbolPen='w', col=3, row=3,rowspan=2, colspan=5)
    lr = pg.LinearRegionItem([400,700])
    lr.setZValue(-10)
    p6.addItem(lr)
    data = np.zeros(1024)
    # points = int(np.random.random()*1024)
    points = bytearray()
    ptr = 0
    def update():
        global curve, data, ptr, p6, ser, points
        points += ser.read_all()
        if len(points) > 2:
            for i in range(len(points)//2):
                data[struct.unpack('>H', points[2*i:2*i+2])[0]>>6] += 1
            points = points[2*int(len(points)/2):]
        curve.setData(data)
        if ptr == 0:
            p6.enableAutoRange('xy', True)  ## stop auto-scaling after the first data set is plotted
        ptr += 1
    timer = QtCore.QTimer()
    timer.timeout.connect(update)
    timer.start(250)
    win1.nextCol()
    win1.nextRow()

    p9 = win1.addPlot(title="Zoom on selected region", col=1, row=3,rowspan=3, colspan=1)
    p9.plot(data, symbolBrush=(255,0,0), symbolPen='w')
    def updatePlot():
        p9.setXRange(*lr.getRegion(), padding=0)
    def updateRegion():
        lr.setRegion(p9.getViewBox().viewRange()[0])
    lr.sigRegionChanged.connect(updatePlot)
    p9.sigXRangeChanged.connect(updateRegion)
    updatePlot()

    # win2 = pg.GraphicsLayoutWidget(show=True, title="Basic plotting examples")
    # win2.resize(1000,600)
    # win2.setWindowTitle('pyqtgraph example: Plotting')

    pg.exec()

    ser.close()