feat(unitree_g1): drive grippers from exo L3/R3 in onboard runner

Onboard now owns the robot, so drive the Damiao grippers directly over CAN from the
exo button flags (L3=button.4->left, R3=button.0->right; pressed=close), reusing
build_gripper/Gripper from run_g1_server. Enable with --grippers.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lerobot/robots/unitree_g1/run_g1_onboard.py

@@ -22,12 +22,16 @@ action (arm joint targets + joystick axes + gripper flags) as JSON over ZMQ. Thi
 applies each action via ``UnitreeG1.send_action`` while the onboard controller thread
 keeps the legs balanced.
 
-Pair with ``run_g1_teleop_client.py`` on the laptop. Grippers/cameras are handled
-separately by ``run_g1_server.py`` and are intentionally out of scope here.
+Pair with ``run_g1_teleop_client.py`` on the laptop. Grippers (exo L3/R3) are driven
+directly over CAN here when ``--grippers`` is passed; cameras stay in ``run_g1_server.py``.
 
-Example (on the robot):
+Examples (on the robot):
 
     python -m lerobot.robots.unitree_g1.run_g1_onboard --controller GrootLocomotionController
+
+    # with grippers (bring CAN up first, e.g. lerobot-setup-can --mode=setup --interfaces=can0,can1)
+    python -m lerobot.robots.unitree_g1.run_g1_onboard --controller GrootLocomotionController \
+        --grippers --gripper-port-left can1 --gripper-port-right can0
 """
 
 import argparse
@@ -39,6 +43,7 @@ import threading
 import zmq
 
 from lerobot.robots.unitree_g1.config_unitree_g1 import UnitreeG1Config
+from lerobot.robots.unitree_g1.run_g1_server import Gripper, build_gripper
 from lerobot.robots.unitree_g1.unitree_g1 import UnitreeG1
 
 logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s", force=True)
@@ -57,6 +62,21 @@ def main() -> None:
         action="store_true",
         help="Enable arm gravity compensation (needs pinocchio/casadi on the robot)",
     )
+    # Gripper control from exo L3/R3 (same wiring as run_g1_server.py).
+    p.add_argument("--grippers", action="store_true", help="Drive Damiao grippers from exo L3/R3")
+    p.add_argument("--gripper-port-left", default="can1", help="CAN interface for LEFT gripper")
+    p.add_argument("--gripper-port-right", default="can0", help="CAN interface for RIGHT gripper")
+    p.add_argument("--gripper-send-id", type=lambda x: int(x, 0), default=0x08, help="Motor send CAN id")
+    p.add_argument("--gripper-recv-id", type=lambda x: int(x, 0), default=0x18, help="Motor recv CAN id")
+    p.add_argument("--gripper-motor-type", default="dm4310", help="Damiao motor type")
+    p.add_argument("--gripper-open-deg", type=float, default=-65.0, help="Gripper OPEN position (deg)")
+    p.add_argument("--gripper-close-deg", type=float, default=0.0, help="Gripper CLOSE position (deg)")
+    p.add_argument("--gripper-kp", type=float, default=15.0, help="MIT position gain (stiffness)")
+    p.add_argument("--gripper-kd", type=float, default=0.5, help="MIT damping gain")
+    p.add_argument(
+        "--gripper-no-fd", dest="gripper_fd", action="store_false", help="Classic CAN (non-FD adapter)"
+    )
+    p.set_defaults(gripper_fd=True)
     args = p.parse_args()
 
     cfg = UnitreeG1Config(
@@ -71,6 +91,25 @@ def main() -> None:
     logger.info("Connecting onboard robot (controller=%s)...", args.controller)
     robot.connect()
 
+    # Grippers: driven directly over CAN from the exo L3/R3 flags in each action
+    # (L3 = remote.button.4 -> left, R3 = remote.button.0 -> right; pressed = close).
+    grippers: dict[str, Gripper] = {}
+    if args.grippers:
+        for side, port in (("L", args.gripper_port_left), ("R", args.gripper_port_right)):
+            grippers[side] = build_gripper(
+                side,
+                port,
+                args.gripper_send_id,
+                args.gripper_recv_id,
+                args.gripper_motor_type,
+                args.gripper_fd,
+                args.gripper_open_deg,
+                args.gripper_close_deg,
+                args.gripper_kp,
+                args.gripper_kd,
+            )
+        logger.info("Grippers enabled: L3 -> left, R3 -> right")
+
     ctx = zmq.Context.instance()
     sock = ctx.socket(zmq.PULL)
     sock.setsockopt(zmq.CONFLATE, 1)  # only ever act on the freshest command
@@ -99,6 +138,14 @@ def main() -> None:
                 continue
 
             robot.send_action(action)
+
+            if grippers:
+                # L3 = remote.button.4 -> left, R3 = remote.button.0 -> right.
+                if "L" in grippers and "remote.button.4" in action:
+                    grippers["L"].apply(bool(action["remote.button.4"]))
+                if "R" in grippers and "remote.button.0" in action:
+                    grippers["R"].apply(bool(action["remote.button.0"]))
+
             n += 1
             if n % 60 == 0:
                 axes = {
@@ -109,6 +156,11 @@ def main() -> None:
                 logger.info("Applied %d actions | axes=%s buttons=%s", n, axes, btn)
     finally:
         logger.info("Shutting down onboard controller...")
+        for g in grippers.values():
+            try:
+                g.bus.disconnect()
+            except Exception as e:  # noqa: BLE001
+                logger.warning("Gripper %s disconnect failed: %s", g.name, e)
         robot.disconnect()