Create python-radar-plotter.py

Python code used to read Arduino angle and distance output, and plot them on a polar plot that emulates a radar plan position indicator

Author: josh-hrisko

python-radar-plotter.py

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+# Python + Arduino-based Radar Plotter
+#
+# ** Works with any motor that outputs angular rotation
+# ** and with any distance sensor (HC-SR04, VL53L0x,LIDAR)
+#
+import numpy as np
+import matplotlib
+matplotlib.use('TkAgg')
+import matplotlib.pyplot as plt
+from matplotlib.widgets import Button
+import serial,sys,glob
+import serial.tools.list_ports as COMs
+#
+#
+############################################
+# Find Arudino ports, select one, then start communication with it
+############################################
+#
+def port_search():
+    if sys.platform.startswith('win'): # Windows
+        ports = ['COM{0:1.0f}'.format(ii) for ii in range(1,256)]
+    elif sys.platform.startswith('linux') or sys.platform.startswith('cygwin'):
+        ports = glob.glob('/dev/tty[A-Za-z]*')
+    elif sys.platform.startswith('darwin'): # MAC
+        ports = glob.glob('/dev/tty.*')
+    else:
+        raise EnvironmentError('Machine Not pyserial Compatible')
+
+    arduinos = []
+    for port in ports: # loop through to determine if accessible
+        if len(port.split('Bluetooth'))>1:
+            continue
+        try:
+            ser = serial.Serial(port)
+            ser.close()
+            arduinos.append(port) # if we can open it, consider it an arduino
+        except (OSError, serial.SerialException):
+            pass
+    return arduinos
+
+arduino_ports = port_search()
+ser = serial.Serial(arduino_ports[0],baudrate=115200) # match baud on Arduino
+ser.flush() # clear the port
+#
+############################################
+# Start the interactive plotting tool and
+# plot 180 degrees with dummy data to start
+############################################
+#
+fig = plt.figure(facecolor='k')
+win = fig.canvas.manager.window # figure window
+screen_res = win.wm_maxsize() # used for window formatting later
+dpi = 150.0 # figure resolution
+fig.set_dpi(dpi) # set figure resolution
+
+# polar plot attributes and initial conditions
+ax = fig.add_subplot(111,polar=True,facecolor='#006d70')
+ax.set_position([-0.05,-0.05,1.1,1.05])
+r_max = 100.0 # can change this based on range of sensor
+ax.set_ylim([0.0,r_max]) # range of distances to show
+ax.set_xlim([0.0,np.pi]) # limited by the servo span (0-180 deg)
+ax.tick_params(axis='both',colors='w')
+ax.grid(color='w',alpha=0.5) # grid color
+ax.set_rticks(np.linspace(0.0,r_max,5)) # show 5 different distances
+ax.set_thetagrids(np.linspace(0.0,180.0,10)) # show 10 angles
+angles = np.arange(0,181,1) # 0 - 180 degrees
+theta = angles*(np.pi/180.0) # to radians
+dists = np.ones((len(angles),)) # dummy distances until real data comes in
+pols, = ax.plot([],linestyle='',marker='o',markerfacecolor = 'w',
+                 markeredgecolor='#EFEFEF',markeredgewidth=1.0,
+                 markersize=10.0,alpha=0.9) # dots for radar points
+line1, = ax.plot([],color='w',
+                  linewidth=4.0) # sweeping arm plot
+
+# figure presentation adjustments
+fig.set_size_inches(0.96*(screen_res[0]/dpi),0.96*(screen_res[1]/dpi))
+plot_res = fig.get_window_extent().bounds # window extent for centering
+win.wm_geometry('+{0:1.0f}+{1:1.0f}'.\
+                format((screen_res[0]/2.0)-(plot_res[2]/2.0),
+                       (screen_res[1]/2.0)-(plot_res[3]/2.0))) # centering plot
+fig.canvas.toolbar.pack_forget() # remove toolbar for clean presentation
+fig.canvas.set_window_title('Arduino Radar')
+
+fig.canvas.draw() # draw before loop
+axbackground = fig.canvas.copy_from_bbox(ax.bbox) # background to keep during loop
+
+############################################
+# button event to stop program
+############################################
+
+def stop_event(event):
+    global stop_bool
+    stop_bool = 1
+prog_stop_ax = fig.add_axes([0.85,0.025,0.125,0.05])
+pstop = Button(prog_stop_ax,'Stop Program',color='#FCFCFC',hovercolor='w')
+pstop.on_clicked(stop_event)
+# button to close window
+def close_event(event):
+    global stop_bool,close_bool
+    if stop_bool:
+        plt.close('all')
+    stop_bool = 1
+    close_bool = 1
+close_ax = fig.add_axes([0.025,0.025,0.125,0.05])
+close_but = Button(close_ax,'Close Plot',color='#FCFCFC',hovercolor='w')
+close_but.on_clicked(close_event)
+
+fig.show()
+
+############################################
+# inifinite loop, constantly updating the
+# 180deg radar with incoming Arduino data
+############################################
+#
+start_word,stop_bool,close_bool = False,False,False
+while True:
+    try:
+        if stop_bool: # stops program
+            fig.canvas.toolbar.pack_configure() # show toolbar
+            if close_bool: # closes radar window
+                plt.close('all')
+            break
+        ser_bytes = ser.readline() # read Arduino serial data
+        decoded_bytes = ser_bytes.decode('utf-8') # decode data to utf-8
+        data = (decoded_bytes.replace('\r','')).replace('\n','')
+        if start_word:
+            vals = [float(ii) for ii in data.split(',')]
+            if len(vals)<2:
+                continue
+            angle,dist = vals # separate into angle and distance
+            if dist>r_max:
+                dist = 0.0 # measuring more than r_max, it's likely inaccurate
+            dists[int(angle)] = dist
+            if angle % 5 ==0: # update every 5 degrees
+                pols.set_data(theta,dists)
+                fig.canvas.restore_region(axbackground)
+                ax.draw_artist(pols)
+
+                line1.set_data(np.repeat((angle*(np.pi/180.0)),2),
+                   np.linspace(0.0,r_max,2))
+                ax.draw_artist(line1)
+
+                fig.canvas.blit(ax.bbox) # replot only data
+                fig.canvas.flush_events() # flush for next plot
+        else:
+            if data=='Radar Start': # stard word on Arduno
+                start_word = True # wait for Arduino to output start word
+                print('Radar Starting...')
+            else:
+                continue
+           
+    except KeyboardInterrupt:
+        plt.close('all')
+        print('Keyboard Interrupt')
+        break