From 1c61b43b1596178adec3d2649b170787f63f1777 Mon Sep 17 00:00:00 2001
From: Steven Palma <imstevenpmwork@ieee.org>
Date: Wed, 14 Jan 2026 17:14:12 +0100
Subject: [PATCH] fix(teleop): add is_connected check to get_action (#2801)

---
 src/lerobot/teleoperators/bi_so_leader/bi_so_leader.py   | 4 ++++
 src/lerobot/teleoperators/gamepad/teleop_gamepad.py      | 5 +++++
 src/lerobot/teleoperators/homunculus/homunculus_arm.py   | 3 +++
 src/lerobot/teleoperators/homunculus/homunculus_glove.py | 3 +++
 src/lerobot/teleoperators/phone/teleop_phone.py          | 6 ++++++
 src/lerobot/teleoperators/so_leader/so_leader.py         | 3 +++
 6 files changed, 24 insertions(+)

diff --git a/src/lerobot/teleoperators/bi_so_leader/bi_so_leader.py b/src/lerobot/teleoperators/bi_so_leader/bi_so_leader.py
index 45c46c100..0fdc32461 100644
--- a/src/lerobot/teleoperators/bi_so_leader/bi_so_leader.py
+++ b/src/lerobot/teleoperators/bi_so_leader/bi_so_leader.py
@@ -18,6 +18,7 @@ import logging
 from functools import cached_property
 
 from lerobot.teleoperators.so_leader import SOLeaderTeleopConfig
+from lerobot.utils.errors import DeviceNotConnectedError
 
 from ..so_leader import SOLeader
 from ..teleoperator import Teleoperator
@@ -92,6 +93,9 @@ class BiSOLeader(Teleoperator):
         self.right_arm.setup_motors()
 
     def get_action(self) -> dict[str, float]:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         action_dict = {}
 
         # Add "left_" prefix
diff --git a/src/lerobot/teleoperators/gamepad/teleop_gamepad.py b/src/lerobot/teleoperators/gamepad/teleop_gamepad.py
index 4dbb49c1d..14d8e3cc1 100644
--- a/src/lerobot/teleoperators/gamepad/teleop_gamepad.py
+++ b/src/lerobot/teleoperators/gamepad/teleop_gamepad.py
@@ -21,6 +21,7 @@ from typing import Any
 import numpy as np
 
 from lerobot.processor import RobotAction
+from lerobot.utils.errors import DeviceNotConnectedError
 
 from ..teleoperator import Teleoperator
 from ..utils import TeleopEvents
@@ -86,6 +87,9 @@ class GamepadTeleop(Teleoperator):
         self.gamepad.start()
 
     def get_action(self) -> RobotAction:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         # Update the controller to get fresh inputs
         self.gamepad.update()
 
@@ -158,6 +162,7 @@ class GamepadTeleop(Teleoperator):
             self.gamepad.stop()
             self.gamepad = None
 
+    @property
     def is_connected(self) -> bool:
         """Check if gamepad is connected."""
         return self.gamepad is not None
diff --git a/src/lerobot/teleoperators/homunculus/homunculus_arm.py b/src/lerobot/teleoperators/homunculus/homunculus_arm.py
index 43116f5c0..53b4dfe68 100644
--- a/src/lerobot/teleoperators/homunculus/homunculus_arm.py
+++ b/src/lerobot/teleoperators/homunculus/homunculus_arm.py
@@ -300,6 +300,9 @@ class HomunculusArm(Teleoperator):
                 logger.debug(f"Error reading frame in background thread for {self}: {e}")
 
     def get_action(self) -> dict[str, float]:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         joint_positions = self._read()
         return {f"{joint}.pos": pos for joint, pos in joint_positions.items()}
 
diff --git a/src/lerobot/teleoperators/homunculus/homunculus_glove.py b/src/lerobot/teleoperators/homunculus/homunculus_glove.py
index fefeec1e8..7feb926ef 100644
--- a/src/lerobot/teleoperators/homunculus/homunculus_glove.py
+++ b/src/lerobot/teleoperators/homunculus/homunculus_glove.py
@@ -326,6 +326,9 @@ class HomunculusGlove(Teleoperator):
                 logger.debug(f"Error reading frame in background thread for {self}: {e}")
 
     def get_action(self) -> dict[str, float]:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         joint_positions = self._read()
         return homunculus_glove_to_hope_jr_hand(
             {f"{joint}.pos": pos for joint, pos in joint_positions.items()}
diff --git a/src/lerobot/teleoperators/phone/teleop_phone.py b/src/lerobot/teleoperators/phone/teleop_phone.py
index 91e613190..402a88d43 100644
--- a/src/lerobot/teleoperators/phone/teleop_phone.py
+++ b/src/lerobot/teleoperators/phone/teleop_phone.py
@@ -165,6 +165,9 @@ class IOSPhone(BasePhone, Teleoperator):
         return True, pos, rot, pose
 
     def get_action(self) -> dict:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         has_pose, raw_position, raw_rotation, fb_pose = self._read_current_pose()
         if not has_pose or not self.is_calibrated:
             return {}
@@ -319,6 +322,9 @@ class AndroidPhone(BasePhone, Teleoperator):
             self._latest_message = message
 
     def get_action(self) -> dict:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         ok, raw_pos, raw_rot, pose = self._read_current_pose()
         if not ok or not self.is_calibrated:
             return {}
diff --git a/src/lerobot/teleoperators/so_leader/so_leader.py b/src/lerobot/teleoperators/so_leader/so_leader.py
index 760ef2eb1..d09262c74 100644
--- a/src/lerobot/teleoperators/so_leader/so_leader.py
+++ b/src/lerobot/teleoperators/so_leader/so_leader.py
@@ -140,6 +140,9 @@ class SOLeader(Teleoperator):
             print(f"'{motor}' motor id set to {self.bus.motors[motor].id}")
 
     def get_action(self) -> dict[str, float]:
+        if not self.is_connected:
+            raise DeviceNotConnectedError(f"{self} is not connected.")
+
         start = time.perf_counter()
         action = self.bus.sync_read("Present_Position")
         action = {f"{motor}.pos": val for motor, val in action.items()}