Control your gripper with the gripper API

The gripper API allows you to give commands to your gripper components for opening and closing a device.

The gripper component supports the following methods:

Establish a connection

To get started using Viam’s SDKs to connect to and control your gripper and the rest of your machine, go to your machine’s page on the Viam app, Navigate to the CONNECT tab’s Code sample page, select your preferred programming language, and copy the sample code.

To show your machine’s API key in the sample code, toggle Include API key.

When executed, this sample code creates a connection to your machine as a client.

The following examples assume you have a gripper called "my_gripper" configured as a component of your machine. If your gripper has a different name, change the name in the code.

Import the gripper package for the SDK you are using:

from viam.components.gripper import Gripper

import (
  "go.viam.com/rdk/components/gripper"
)

API

Open

Opens the gripper.

my_gripper = Gripper.from_robot(robot=machine, name="my_gripper")

# Open the gripper.
await my_gripper.open()

myGripper, err := gripper.FromRobot(machine, "my_gripper")

// Open the gripper.
err := myGripper.Open(context.Background(), nil)

await myGripper.open();

Grab

Closes the gripper until it grabs something or closes completely, and returns whether it grabbed something or not.

my_gripper = Gripper.from_robot(robot=machine, name="my_gripper")

# Grab with the gripper.
grabbed = await my_gripper.grab()

myGripper, err := gripper.FromRobot(machine, "my_gripper")

// Grab with the gripper.
grabbed, err := myGripper.Grab(context.Background(), nil)

await myGripper.grab();

IsMoving

Returns whether the gripper is actively moving (or attempting to move) under its own power.

my_gripper = Gripper.from_robot(robot=machine, name="my_gripper")

# Check whether the gripper is currently moving.
moving = await my_gripper.is_moving()
print('Moving:', moving)

// This example shows using IsMoving with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

// Stop all motion of the arm. It is assumed that the arm stops immediately.
myArm.Stop(context.Background(), nil)

// Log if the arm is currently moving.
is_moving, err := myArm.IsMoving(context.Background())
logger.Info(is_moving)

var isItMoving = await myGripper.isMoving();

Stop

Stops the gripper. It is assumed that the gripper stops immediately, so IsMoving will return false after calling Stop.

my_gripper = Gripper.from_robot(robot=machine, name="my_gripper")

# Stop the gripper.
await my_gripper.stop()

// This example shows using Stop with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

// Stop all motion of the arm. It is assumed that the arm stops immediately.
err = myArm.Stop(context.Background(), nil)

await myGripper.stop();

GetGeometries

Get all the geometries associated with the gripper in its current configuration, in the frame of the gripper. The motion and navigation services use the relative position of inherent geometries to configured geometries representing obstacles for collision detection and obstacle avoidance while motion planning.

my_gripper = Gripper.from_robot(robot=machine, name="my_gripper")
geometries = await my_gripper.get_geometries()

if geometries:
    # Get the center of the first geometry
    print(f"Pose of the first geometry's centerpoint: {geometries[0].center}")

// This example shows using Geometries with an gripper component.
myGripper, err := gripper.FromRobot(machine, "my_gripper")

geometries, err := myGripper.Geometries(context.Background(), nil)

if len(geometries) > 0 {
   // Get the center of the first geometry
   elem := geometries[0]
   fmt.Println("Pose of the first geometry's center point:", elem.Pose())
}

Reconfigure

Reconfigure this resource. Reconfigure must reconfigure the resource atomically and in place.

DoCommand

Execute model-specific commands that are not otherwise defined by the component API. For built-in models, model-specific commands are covered with each model’s documentation. If you are implementing your own gripper and add features that have no built-in API method, you can access them with DoCommand.

// Example using doCommand with an arm component
const command = {'cmd': 'test', 'data1': 500};
var result = myArm.doCommand(command);

GetResourceName

Get the ResourceName for this gripper with the given name.

my_gripper_name = Gripper.get_resource_name("my_gripper")

final myGripperResourceName = myGripper.getResourceName("my_gripper");

Close

Safely shut down the resource and prevent further use.

my_gripper = Gripper.from_robot(robot=machine, name="my_gripper")
await my_gripper.close()

myGripper, err := gripper.FromRobot(machine, "my_gripper")

err = myGripper.Close(context.Background())