Using GCA and GCF causes weird stuff to happen when buttons are added.

ch-13/3-moving-poses-with-sensors/computer/display_from_robot.py

@@ -40,18 +40,18 @@ class RobotDisplay:
                 self.pose_uv = np.array([np.cos(angle_rads), np.sin(angle_rads)])
 
     def draw(self):
-        plt.gca().clear()
+        self.ax.clear()
         if self.arena:
             for line in self.arena["arena"]:
-                plt.gca().plot(
+                self.ax.plot(
                     [line[0][0], line[1][0]], [line[0][1], line[1][1]], color="black"
                 )
             for line in self.arena["target_zone"]:
-                plt.gca().plot(
+                self.ax.plot(
                     [line[0][0], line[1][0]], [line[0][1], line[1][1]], color="red"
                 )
         if len(self.pose_coords) > 0:
-            plt.quiver(self.pose_coords[0], self.pose_coords[1], self.pose_uv[0], self.pose_uv[1], color="blue")
+            self.ax.quiver(self.pose_coords[0], self.pose_coords[1], self.pose_uv[0], self.pose_uv[1], color="blue")
 
     async def send_command(self, command):
         request = json.dumps({"command": command}).encode()
@@ -67,9 +67,10 @@ class RobotDisplay:
     async def main(self):
         plt.ion()
         await self.ble_connection.connect()
+        self.fig, self.ax = plt.subplots()
         try:
             await self.send_command("arena")
-            plt.gcf().canvas.mpl_connect("close_event", self.handle_close)
+            self.fig.canvas.mpl_connect("close_event", self.handle_close)
             start_button = Button(plt.axes([0.7, 0.05, 0.1, 0.075]), "Start")
             start_button.on_clicked(self.start)
             stop_button = Button(plt.axes([0.81, 0.05, 0.1, 0.075]), "Stop")

ch-13/3-moving-poses-with-sensors/robot/code.py

@@ -30,6 +30,9 @@ class Simulation:
     finally:
       robot.stop()
 
+def send_json(data):
+  robot.uart.write((json.dumps(data)+"\n").encode())
+
 async def command_handler(simulation):
   simulation_task = None
   while True:
@@ -37,22 +40,16 @@ async def command_handler(simulation):
       print("Receiving data...")
       try:
         data = robot.uart.readline().decode()
-      except UnicodeError:
-        print("Invalid data")
-        continue
-      try:
         request = json.loads(data)
-        print(f"Received command: {request}")
-      except ValueError:
-        print("Invalid JSON")
+      except (UnicodeError, ValueError):
+        print("Invalid data")
         continue
       # {"command": "arena"}
       if request["command"] == "arena":
-         response = {
+         send_json({
             "arena": arena.boundary_lines,
             "target_zone": arena.target_zone,
-         }
-         robot.uart.write((json.dumps(response)+"\n").encode())
+         })
       elif request["command"] == "start":
         print("Starting simulation")
         if simulation_task is None or simulation_task.done():
@@ -63,10 +60,9 @@ async def command_handler(simulation):
           simulation_task.cancel()
           simulation_task = None
     else:
-      response = {
+      send_json({
         "poses": simulation.poses.tolist(),
-      }
-      robot.uart.write((json.dumps(response)+"\n").encode())
+      })
     await asyncio.sleep(0.1)
 
 simulation= Simulation()