making Lidar - step 03 : Timer added

이젠 마구 Timer가 마구 계속 찍어내기 시작.

Timer가 지속적으로 부르는 _Update 안에 Lidar 데이타를 업데이트해 줘야만 한다.

 

 

# -*- coding: utf-8 -*-
"""
From main library's example, ScatterPlot.py, 
I will take out one of chart to make it for Lidar data display.
"""
from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph as pg
import numpy as np
from collections import namedtuple
from itertools import chain
import sys

app = QtGui.QApplication([])
mw = QtGui.QMainWindow()
mw.resize(530,500)
view = pg.GraphicsLayoutWidget()  ## GraphicsView with GraphicsLayout inserted by default
mw.setCentralWidget(view)
mw.show()
mw.setWindowTitle('Lidar Test ')

## create four areas to add plots
w1 = view.addPlot()

# Add polar grid lines
w1.addLine(x=0, pen=0.3)
w1.addLine(y=0, pen=0.3)
for r in range(2, 2000, 200):   # Draw 10 circles
   # Adding circle (x, y, width, height)
   cwidth = r * 2
   cheight = r * 2
   circle = pg.QtGui.QGraphicsEllipseItem(-r, -r, cwidth, cheight)
   circle.setPen(pg.mkPen(0.3))
   w1.addItem(circle)  
   
   
######  I have to focus on putting data here.   
def _update():
   n = 360
   
   s1 = pg.ScatterPlotItem(size=5, pen=pg.mkPen(None), brush=pg.mkBrush(255, 255, 255, 120))
   # Make 2 Dimension (X,Y) points array of 360 dots on scale of 500 for 500 mm.
   pos = np.random.normal(size=(2,n), scale=500)
   spots = [{'pos': pos[:,i], 'data': 1} for i in range(n)] + [{'pos': [0,0], 'data': 1}]
   s1.addPoints(spots)
   w1.addItem(s1)

timer = QtCore.QTimer(interval=1)
timer.timeout.connect(_update)
timer.start(300)  # Update every 300 millisecond

_update()   # Calling only once, timer will keep calling them 


if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()