# Drive a rover in a square in 2 minutes Use a Viam SDK to program a rover to move in a square. > Source: https://docs.viam.com/try/viam-rover/drive-rover/ · Last updated: 2026-05-23 In this guide you'll write code that makes a rover drive in a square. > **You will learn:** > > > > - How to run control code with Viam SDKs > - How to use the base API to move a rover in a square > > > **Renting a Viam Rover?:** > > > See [Rent a Viam Rover](/try/viam-rover/rent-a-rover/) for reservation steps, session time limits, and answers to common rental questions. > Error
## Requirements You don't need to buy or own any hardware to complete this tutorial. You only need the following: - A Linux, macOS or Windows computer that can run SDK code. - A [borrowed Viam Rover](https://app.viam.com/try), [your own Viam Rover](/try/viam-rover/), or [another mobile robot](/tutorials/configure/configure-rover/). You can use [Try Viam](https://app.viam.com/try) to borrow a rover online at no cost which is already configured with all the components you need. If you have your own rover on hand, whether it's a [Viam rover](https://www.viam.com/resources/rover) or not, these instructions work for any wheeled robot that can be configured as a [base component](/reference/components/base/wheeled/). ## Instructions Follow these steps to get your rover ready and write code to control it: ### Borrowed Try Viam Rover **Step 1: Borrow a Viam Rover** Go to [Try Viam](https://app.viam.com/try) and [borrow a rover](/try/viam-rover/rent-a-rover/). If a rover is available, the rover will take up to 30 seconds to be configured for you.
**Tip:** If you are running out of time during your session, you can [extend your rover session](/try/viam-rover/rent-a-rover/#extend-your-reservation) as long as there are no other reservations.
### Other Rover
**Important:** If you are using your own robot for this tutorial instead of [borrowing one](https://app.viam.com/try), be sure to [follow the setup instructions and install `viam-server`](/set-up-a-machine/first-machine/) on it, and connect and [configure](/tutorials/configure/configure-rover/) its hardware before proceeding with this tutorial.
**Step 2: Install an SDK** Navigate to your machine's **CONNECT** tab. Click on any of the listed languages and follow the instructions to install the SDK. To install your preferred Viam SDK on your Linux or macOS development machine or [single-board computer](/reference/components/board/), run one of the following commands in your terminal: ### Python If you are using the Python SDK, [set up a virtual environment](/reference/sdks/python/python-venv/) to package the SDK inside before running your code, avoiding conflicts with other projects or your system. For macOS (both Intel `x86_64` and Apple Silicon) or Linux (`x86`, `aarch64`, `armv6l`), run the following commands: ```sh python3 -m venv .venv source .venv/bin/activate pip install viam-sdk ``` Windows is not supported. If you are using Windows, use the [Windows Subsystem for Linux (WSL)](https://learn.microsoft.com/en-us/windows/wsl/install) and install the Python SDK using the preceding instructions for Linux. For other unsupported systems, see [Installing from source](https://python.viam.dev/#installing-from-source). ### Go ```sh go get go.viam.com/rdk/robot/client ``` ### TypeScript ```sh npm install @viamrobotics/sdk ``` ### Flutter ```sh flutter pub add viam_sdk ``` ### C++ Follow the [instructions on the GitHub repository](https://github.com/viamrobotics/viam-cpp-sdk/blob/main/doc/BUILDING.md). **Step 3: Copy and run the sample code** The sample code on the **CONNECT** tab will show you how to authenticate and connect to a machine, as well as some of the methods you can use on your configured components and services. ### Python Go to the **CONNECT** tab and select **Python**. Save your API key and API key ID as environment variables or include them in the code: To show your machine’s API key in the sample code, toggle **Include API key**. {{< alert title=“Caution: Keep your API key safe” color=“caution” >}} We strongly recommend that you add your API key as an environment variable. Anyone with your API key can access your machine, and the computer running your machine. {{< /alert >}} Copy the code into a file called square.py and run the sample code to connect to your machine: ```sh python3 square.py ``` The program prints an array of resources. These are the components and services that the machine is configured with on Viam. ```sh python3 square.py 2024-08-09 13:21:52,423 INFO viam.rpc.dial (dial.py:293) Connecting to socket: /tmp/proxy-BzFWLZQ2.sock Resources: [, , , , , , , , ] ``` ### Go Go to the **CONNECT** tab and select **Golang**. Save your API key and API key ID as environment variables or include them in the code: To show your machine’s API key in the sample code, toggle **Include API key**. {{< alert title=“Caution: Keep your API key safe” color=“caution” >}} We strongly recommend that you add your API key as an environment variable. Anyone with your API key can access your machine, and the computer running your machine. {{< /alert >}} Copy the code into a file called square.go. Initialize your project, and install the necessary libraries, and then run the program to verify that the Viam SDK is properly installed and that the `viam-server` instance on your machine is live: ```sh go mod init square go mod tidy go run square.go ``` The program prints an array of resources. These are the components and services that the machine is configured with on Viam. ```sh go run square.go 2024-08-09T11:27:05.034Z DEBUG client.webrtc rpc/wrtc_client.go:111 connecting to signaling server {"signaling_server":"app.viam.com:443","host":"muddy-snow-main.7kp7y4p393.viam.cloud"} 2024-08-09T11:27:05.314Z DEBUG client.webrtc rpc/wrtc_client.go:125 connected to signaling server {"signaling_server":"app.viam.com:443"} ... 2024-08-09T11:27:08.916Z INFO client test-rover/square.go:33 Resources: 2024-08-09T11:27:08.916Z INFO client test-rover/square.go:34 [rdk:component:board/local rdk:component:base/viam_base rdk:service:motion/builtin rdk:component:motor/right rdk:component:encoder/Renc rdk:component:encoder/Lenc rdk:service:sensors/builtin rdk:component:motor/left rdk:component:camera/cam] ``` ### TypeScript > **Fast track:** > > > > If you want to get the full sample code now, run the following command which will set up the files for you: > > ```sh {class="command-line" data-prompt="$"} > npm create robot-app > ``` > > Then, copy and paste your API key and API key ID, and machine address into the .env file. > If you have run this command and added your environment variables, skip ahead to running the program. > > Go to the **CONNECT** tab and select **Browser TS**. Save your API key and API key ID as environment variables or include them in the code: To show your machine's API key in the sample code, toggle **Include API key**. {{< alert title="Caution: Keep your API key safe" color="caution" >}} We strongly recommend that you add your API key as an environment variable. Anyone with your API key can access your machine, and the computer running your machine. {{< /alert >}} Copy the code into a file called main.ts. Create another file named package.json with the following contents: ```json {class="line-numbers linkable-line-numbers"} { "name": "test-rover", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "start": "esbuild ./main.ts --bundle --outfile=static/main.js --servedir=static", "test": "echo \"Error: no test specified\" && exit 1" }, "author": "Viam Docs Team", "license": "ISC", "devDependencies": { "esbuild": "*" }, "dependencies": { "@viamrobotics/sdk": "*" } } ``` Create a folder static and inside it another file named index.html. Add the following markup: ```html {class="line-numbers linkable-line-numbers"} Drive a Rover

Drive a rover in a square

We recommend you open the developer tools in your browser to see logs.

Also open a second window with the your rover's CONTROL tab, which allows you to interact with your rover's resources. Click on one of the camera panels and toggle the camera stream on so you can observe the rover's movements.

``` Run the following commands to install the necessary libraries, and then run the program to verify that the Viam SDK is properly installed and that the `viam-server` instance on your machine is live: ```sh {class="command-line" data-prompt="$"} npm install npm start ``` Open a web browser and visit `localhost:8000`. You should see a disabled button that says `Click me to drive rover in square`. Open the developer console to see the console output. If you successfully configured your machine and it is able to connect to Viam, you will see some output including the names of your rover's resources. These are the components and services that the machine is configured with on Viam. ### Flutter Flutter code must be launched from inside a running Flutter application. To get started programming your rover with Flutter, follow the instructions to [Build a Flutter App that Integrates with Viam](/tutorials/control/flutter-app/). ### C++ Go to the **CONNECT** tab and select **C++**. Save your API key and API key ID as environment variables or include them in the code: To show your machine’s API key in the sample code, toggle **Include API key**. {{< alert title=“Caution: Keep your API key safe” color=“caution” >}} We strongly recommend that you add your API key as an environment variable. Anyone with your API key can access your machine, and the computer running your machine. {{< /alert >}} Copy the code into a file called drive_in_square.cpp. Compile your code, and then run the program to verify that the Viam SDK is properly installed and that the `viam-server` instance on your machine is live: ```sh cmake . -G Ninja ninja all ./drive_in_square ``` The program prints an array of resources. These are the components and services that the machine is configured with on Viam. ```sh ./drive_in_square Resources: rdk:component:motor/right rdk:component:encoder/Renc rdk:component:encoder/Lenc rdk:service:sensors/builtin rdk:component:motor/left rdk:component:camera/cam rdk:component:board/local rdk:component:base/viam_base rdk:service:motion/builtin ... ``` **Step 4: Drive a rover in a square** Now that you have connected the rover to Viam with the SDK, you can write code to move the rover in a square: ### Python The base is responsible for controlling the motors attached to the base of the rover. Ensure that the `Base` class is being imported: ```python from viam.components.base import Base ``` Then paste this snippet above your `main()` function, it will move any base passed to it in a square: ```python async def moveInSquare(base): for _ in range(4): # moves the rover forward 500mm at 500mm/s await base.move_straight(velocity=500, distance=500) print("move straight") # spins the rover 90 degrees at 100 degrees per second await base.spin(velocity=100, angle=90) print("spin 90 degrees") ``` Next, remove all the code in the `main()` function between where the machine connection is established and closed and instead initialize your `base` and invoke the `moveInSquare()` function. On the Try Viam rovers, the default base name is `viam_base`. If you have a different base name, update the name in your code. ```python async def main(): machine = await connect() # Get the base component from the rover roverBase = Base.from_robot(machine, 'viam_base') # Move the rover in a square await moveInSquare(roverBase) await machine.close() ``` If you have a borrowed Try Viam rover, navigate to your machine’s **CONTROL** tab, which allows you to interact with your machine’s [resources](/reference/glossary/#term-resource) . Click on one of the camera panels and toggle the camera stream on so you can observe the rover’s movements. Then run your code and watch your rover move in a square.
### Go The base is responsible for controlling the motors attached to the base of the rover. Ensure that the `Base` class is being imported: ```go import ( // Be sure to keep all of the other imported libraries "go.viam.com/rdk/components/base" ) ``` Then paste this snippet above your `main()` function, it will move any base passed to it in a square: ```go func moveInSquare(ctx context.Context, base base.Base, logger logging.Logger) { for i := 0; i < 4; i++ { // moves the rover forward 600mm at 500mm/s base.MoveStraight(ctx, 600, 500.0, nil) logger.Info("move straight") // spins the rover 90 degrees at 100 degrees per second base.Spin(ctx, 90, 100.0, nil) logger.Info("spin 90 degrees") } } ``` Next, remove all the code in the `main()` function after the machine connection is established and instead initialize your `base` and invoke the `moveInSquare()` function. Also remove any unused imports. On the Try Viam rovers, the default base name is `viam_base`. If you have a different base name, update the name in your code. ```go func main() { logger := logging.NewLogger("client") machine, err := client.New( context.Background(), // TODO: Replace "" with address from the CONNECT tab. "", logger, client.WithDialOptions(client.WithEntityCredentials( // Replace "" (including brackets) with your machine's // API key ID "", client.Credentials{ Type: client.CredentialsTypeAPIKey, // Replace "" (including brackets) with your machine's API key Payload: "", })), ) if err != nil { logger.Fatal(err) } defer machine.Close(context.Background()) // Get the base from the rover roverBase, err := base.FromProvider(machine, "viam_base") if err != nil { logger.Fatalf("cannot get base: %v", err) } // Move the rover in a square moveInSquare(context.Background(), roverBase, logger) } ``` If you have a borrowed Try Viam rover, navigate to your machine’s **CONTROL** tab, which allows you to interact with your machine’s [resources](/reference/glossary/#term-resource) . Click on one of the camera panels and toggle the camera stream on so you can observe the rover’s movements. Then run your code and watch your rover move in a square.
### TypeScript Above the `main` function, add the following function that initializes your rover base client and drives it in a square. On the Try Viam rovers, the default base name is `viam_base`. If you have a different base name, update the name in your code. ```ts // This function moves a base component in a square. async function moveInSquare(client: VIAM.RobotClient) { // TODO: Replace with the name of the base on your machine. const name = "viam_base"; const baseClient = new VIAM.BaseClient(client, name); try { button().disabled = true; for (let i = 0; i < 4; i++) { console.log("move straight"); await baseClient.moveStraight(500, 500); console.log("spin 90 degrees"); await baseClient.spin(90, 100); } } finally { button().disabled = false; } } ``` Underneath the `moveInSquare` function, add this `button` function which gets the `main-button` button from the page loaded from `index.html`: ```ts // This function gets the button element function button() { return document.getElementById("main-button"); } ``` Next, register a listener on the button you obtain from the `button` function and make it invoke the `moveInSquare` function. Place this code after the rover connection code: ```ts button().onclick = async () => { await moveInSquare(machine); }; button().disabled = false; ``` Your main function should now look like this: ```ts async function main() { // TODO: Replace "" with address from the CONNECT tab. const host = ""; const machine = await VIAM.createRobotClient({ host, credentials: { // TODO: Replace "" (including brackets) with your machine's // API key type: "api-key", payload: "", // TODO: Replace "" (including brackets) with your machine's // API key ID authEntity: "", }, signalingAddress: "https://app.viam.com:443", }); button().onclick = async () => { await moveInSquare(machine); }; button().disabled = false; } ``` Save your code and refresh the browser page. When the connection to the rover is established, the `Click me to drive rover in square` button will become enabled. If you have a borrowed Try Viam rover, open a tab and navigate to your machine’s **CONTROL** tab, which allows you to interact with your rover’s [resources](/reference/glossary/#term-resource) . Click on one of the camera panels and toggle the camera stream on so you can observe the rover’s movements. Go back to the `Click me to drive rover in square` button and click the button to run your code and switch back to the **CONTROL** tab to watch your rover move in a square.
### Flutter Add a new file to your application in /lib called base_screen.dart. Paste this code into your file: ```dart /// This is the BaseScreen, which allows us to control a Base. import 'package:flutter/material.dart'; import 'package:viam_sdk/viam_sdk.dart'; import 'package:viam_sdk/widgets.dart'; class BaseScreen extends StatelessWidget { final Base base; const BaseScreen(this.base, {super.key}); Future moveSquare() async { for (var i=0; i<4; i++) { await base.moveStraight(500, 500); await base.spin(90, 100); } } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: Text(base.name)), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ ElevatedButton( onPressed: moveSquare, child: const Text('Move Base in Square'), ), ])) ,);}} ``` This code creates a screen with a singular centered button that, when pressed, calls on the `moveSquare()` method to drive the base in a square. Then, replace the contents of robot_screen.dart with the following file, or add the highlighted lines of code to your program in the locations indicated: ```dart /// This is the screen that shows the resources available on a robot (or smart machine). /// It takes in a Viam app client instance, as well as a robot client. /// It then uses the Viam client instance to create a connection to that robot client. /// Once the connection is established, you can view the resources available /// and send commands to them. import 'package:flutter/material.dart'; import 'package:viam_sdk/protos/app/app.dart'; import 'package:viam_sdk/viam_sdk.dart'; import 'base_screen.dart'; class RobotScreen extends StatefulWidget { final Viam _viam; final Robot robot; const RobotScreen(this._viam, this.robot, {super.key}); @override State createState() => _RobotScreenState(); } class _RobotScreenState extends State { /// Similar to previous screens, start with [_isLoading] to true. bool _isLoading = true; /// This is the [RobotClient], which allows you to access /// all the resources of a Viam Smart Machine. /// This differs from the [Robot] provided to us in the widget constructor /// in that the [RobotClient] contains a direct connection to the Smart Machine /// and its resources. The [Robot] object simply contains information about /// the Smart Machine, but is not actually connected to the machine itself. /// /// This is initialized late because it requires an asynchronous /// network call to establish the connection. late RobotClient client; @override void initState() { super.initState(); // Call our own _initState method to initialize our state. _initState(); } @override void dispose() { // You should always close the [RobotClient] to free up resources. // Calling [RobotClient.close] will clean up any tasks and // resources created by Viam. if (_isLoading == false) { client.close(); } super.dispose(); } /// This method will get called when the widget initializes its state. /// It exists outside the overridden [initState] function since it's async. Future _initState() async { // Using the authenticated [Viam] the received as a parameter, // the app can obtain a connection to the Robot. // There is a helpful convenience method on the [Viam] instance for this. final robotClient = await widget._viam.getRobotClient(widget.robot); setState(() { client = robotClient; _isLoading = false; }); } /// A computed variable that returns the available [ResourceName]s of /// this robot in an alphabetically sorted list. List get _sortedResourceNames { return client.resourceNames..sort((a, b) => a.name.compareTo(b.name)); } bool _isNavigable(ResourceName rn) { if (rn.subtype == Base.subtype.resourceSubtype) { return true; } return false; } void _navigate(ResourceName rn) { if (rn.subtype == Base.subtype.resourceSubtype) { final base = Base.fromRobot(client, rn.name); Navigator.of(context).push(MaterialPageRoute(builder: (_) => BaseScreen(base))); } } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: Text(widget.robot.name)), body: _isLoading ? const Center(child: CircularProgressIndicator.adaptive()) : ListView.builder( itemCount: client.resourceNames.length, itemBuilder: (_, index) { final resourceName = _sortedResourceNames[index]; return ListTile( title: Text(resourceName.name), subtitle: Text( '${resourceName.namespace}:${resourceName.type}:${resourceName.subtype}'), onTap: () => _navigate(resourceName), trailing: _isNavigable(resourceName) ? Icon(Icons.chevron_right) : SizedBox.shrink(), ); })); } } ``` This imports the base_screen.dart file into the program and adds logic to check if a [resource](/reference/glossary/#term-resource) is “navigable”, or, has a screen made for it. Base is the only resource that is navigable. To navigate to the base screen, save your code and launch your simulator. Navigate to the robot screen of a (live) machine with a base resource configured, and see the resources displayed like the following: Machine resources listed in an example Flutter app Then, click on the base to display the base screen. You may need to scroll to the bottom of the list of resources. Button to drive a rover in a square in an example Flutter app Click on the button to move your rover in a square: ### C++ The base is responsible for controlling the motors attached to the base of the rover. Ensure that the `Base` class is being imported: ```cpp #include ``` Additionally, add the following namespaces under your imports: ```cpp using namespace viam::sdk; using std::cerr; using std::cout; using std::endl; ``` Then paste this snippet above your main() function, it will move any base passed to it in a square: ```cpp void move_in_square(std::shared_ptr base) { for (int i = 0; i < 4; ++i) { cout << "Move straight" << endl; // Move the base forward 600mm at 500mm/s base->move_straight(500, 500); cout << "Spin" << endl; // Spin the base by 90 degree at 100 degrees per second base->spin(90, 100); } } ``` Next, remove all the code in the `main()` function after the machine connection is established, and instead initialize your base and invoke the `moveInSquare()` function. On the Try Viam rovers, the default base name is `viam_base`. If you have a different base name, update the name in your code. ```cpp int main() { // Every Viam C++ SDK program must have one and only one Instance object which is created // before // any other C++ SDK objects and stays alive until all Viam C++ SDK objects are destroyed. Instance inst; // TODO: Replace "" with address from the CONNECT tab. std::string host(""); DialOptions dial_opts; // TODO: Replace "" with your machine's API key ID dial_opts.set_entity(std::string("")); // TODO: Replace "" with your machine's API key Credentials credentials("api-key", ""); dial_opts.set_credentials(credentials); boost::optional opts(dial_opts); Options options(0, opts); auto machine = RobotClient::at_address(host, options); std::cout << "Resources:\n"; for (const Name& resource : machine->resource_names()) { std::cout << "\t" << resource << "\n"; } std::string base_name("viam_base"); cout << "Getting base: " << base_name << endl; std::shared_ptr base; try { base = machine->resource_by_name(base_name); move_in_square(base); } catch (const std::exception& e) { cerr << "Failed to find " << base_name << ". Exiting." << endl; throw; } return EXIT_SUCCESS; } ``` If you have a borrowed Try Viam rover, navigate to your machine’s **CONTROL** tab, which allows you to interact with your machine’s [resources](/reference/glossary/#term-resource) . Click on one of the camera panels and toggle the camera stream on so you can observe the rover’s movements. Then run your code and watch your rover move in a square.
> **Tip:** > > If you are interested to learn about what other commands you can give to a base, see the standardized [base API](/reference/apis/components/base/#api) for a full list of available API methods. ## Complete code This is the complete code for the tutorial: ### Python ```python import asyncio from viam.components.base import Base from viam.robot.client import RobotClient from viam.rpc.dial import Credentials, DialOptions async def connect(): opts = RobotClient.Options.with_api_key( # TODO: Replace "" (including brackets) with your machine's # API key api_key='', # TODO: Replace "" (including brackets) with your machine's # API key ID api_key_id='' ) # TODO: Replace "" with address from the CONNECT tab. return await RobotClient.at_address("", opts) async def moveInSquare(base): for _ in range(4): # moves the rover forward 500mm at 500mm/s await base.move_straight(velocity=500, distance=500) print("move straight") # spins the rover 90 degrees at 100 degrees per second await base.spin(velocity=100, angle=90) print("spin 90 degrees") async def main(): async with await connect() as machine: roverBase = Base.from_robot(machine, 'viam_base') # Move the rover in a square await moveInSquare(roverBase) if __name__ == '__main__': asyncio.run(main()) ``` ### Go ```go package main import ( "context" "go.viam.com/rdk/components/base" "go.viam.com/rdk/logging" "go.viam.com/rdk/robot/client") func moveInSquare(ctx context.Context, base base.Base, logger logging.Logger) { for i := 0; i < 4; i++ { // moves the rover forward 600mm at 500mm/s base.MoveStraight(ctx, 600, 500.0, nil) logger.Info("move straight") // spins the rover 90 degrees at 100 degrees per second base.Spin(ctx, 90, 100.0, nil) logger.Info("spin 90 degrees") } } func main() { logger := logging.NewLogger("client") machine, err := client.New( context.Background(), // TODO: Replace "" with address from the CONNECT tab. "", logger, client.WithDialOptions(client.WithEntityCredentials( // TODO: Replace "" (including brackets) with your machine's // API key ID "", client.Credentials{ Type: client.CredentialsTypeAPIKey, // TODO: Replace "" (including brackets) with your machine's // API key Payload: "", })), ) if err != nil { logger.Fatal(err) } defer machine.Close(context.Background()) // Get the base from the rover roverBase, err := base.FromProvider(machine, "viam_base") if err != nil { logger.Fatalf("cannot get base: %v", err) } // Move the rover in a square moveInSquare(context.Background(), roverBase, logger) } ``` ### TypeScript package.json: ```json { "name": "test-rover", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "start": "esbuild ./main.ts --bundle --outfile=static/main.js --servedir=static", "test": "echo \"Error: no test specified\" && exit 1" }, "author": "Viam Docs Team", "license": "ISC", "devDependencies": { "esbuild": "*" }, "dependencies": { "@viamrobotics/sdk": "*" } } ``` static/index.html: ```html Drive a Rover

Drive a rover in a square

We recommend you open the developer tools in your browser to see logs.

Also open a second window and navigate to your rover's CONTROL tab, which allows you to interact with your rover's resources. Click on one of the camera panels and toggle the camera stream on so you can observe the rover's movements.

``` main.ts: ```ts // This code must be run in a browser environment. import * as VIAM from "@viamrobotics/sdk"; // This function moves a base component in a square. async function moveInSquare(client: VIAM.RobotClient) { // TODO: Replace with the name of the base on your machine. const name = "viam_base"; const baseClient = new VIAM.BaseClient(client, name); try { button().disabled = true; for (let i = 0; i < 4; i++) { console.log("move straight"); await baseClient.moveStraight(500, 500); console.log("spin 90 degrees"); await baseClient.spin(90, 100); } } finally { button().disabled = false; } } // This function gets the button element function button() { return document.getElementById("main-button"); } const main = async () => { // TODO: Replace "" with address from the CONNECT tab. const host = ""; const machine = await VIAM.createRobotClient({ host, credentials: { // TODO: Replace "" (including brackets) with your machine's // API key type: "api-key", payload: "", // TODO: Replace "" (including brackets) with your machine's // API key ID authEntity: "", }, signalingAddress: "https://app.viam.com:443", }); button().onclick = async () => { await moveInSquare(machine); }; button().disabled = false; }; main().catch((error) => { console.error("encountered an error:", error); }); ``` ### Flutter robot_screen.dart: ```dart /// This is the BaseScreen, which allows us to control a Base. import 'package:flutter/material.dart'; import 'package:viam_sdk/viam_sdk.dart'; import 'package:viam_sdk/widgets.dart'; class BaseScreen extends StatelessWidget { final Base base; const BaseScreen(this.base, {super.key}); Future moveSquare() async { for (var i=0; i<4; i++) { await base.moveStraight(500, 500); await base.spin(90, 100); } } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: Text(base.name)), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ ElevatedButton( onPressed: moveSquare, child: const Text('Move Base in Square'), ), ])) ,);}} ``` base_screen.dart: ```dart /// This is the screen that shows the resources available on a robot (or smart machine). /// It takes in a Viam app client instance, as well as a robot client. /// It then uses the Viam client instance to create a connection to that robot client. /// Once the connection is established, you can view the resources available /// and send commands to them. import 'package:flutter/material.dart'; import 'base_screen.dart'; import 'package:viam_sdk/protos/app/app.dart'; import 'package:viam_sdk/viam_sdk.dart'; class RobotScreen extends StatefulWidget { final Viam _viam; final Robot robot; const RobotScreen(this._viam, this.robot, {super.key}); @override State createState() => _RobotScreenState(); } class _RobotScreenState extends State { /// Similar to previous screens, start with [_isLoading] to true. bool _isLoading = true; /// This is the [RobotClient], which allows you to access /// all the resources of a Viam Smart Machine. /// This differs from the [Robot] provided to us in the widget constructor /// in that the [RobotClient] contains a direct connection to the Smart Machine /// and its resources. The [Robot] object simply contains information about /// the Smart Machine, but is not actually connected to the machine itself. /// /// This is initialized late because it requires an asynchronous /// network call to establish the connection. late RobotClient client; @override void initState() { super.initState(); // Call our own _initState method to initialize our state. _initState(); } @override void dispose() { // You should always close the [RobotClient] to free up resources. // Calling [RobotClient.close] will clean up any tasks and // resources created by Viam. client.close(); super.dispose(); } /// This method will get called when the widget initializes its state. /// It exists outside the overridden [initState] function since it's async. Future _initState() async { // Using the authenticated [Viam] the received as a parameter, // the app can obtain a connection to the Robot. // There is a helpful convenience method on the [Viam] instance for this. final robotClient = await widget._viam.getRobotClient(widget.robot); setState(() { client = robotClient; _isLoading = false; }); } /// A computed variable that returns the available [ResourceName]s of /// this robot in an alphabetically sorted list. List get _sortedResourceNames { return client.resourceNames..sort((a, b) => a.name.compareTo(b.name)); } bool _isNavigable(ResourceName rn) { if (rn.subtype == Base.subtype.resourceSubtype) { return true; } return false; } void _navigate(ResourceName rn) { if (rn.subtype == Base.subtype.resourceSubtype) { final base = Base.fromRobot(client, rn.name); Navigator.of(context).push(MaterialPageRoute(builder: (_) => BaseScreen(base))); } } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: Text(widget.robot.name)), body: _isLoading ? const Center(child: CircularProgressIndicator.adaptive()) : ListView.builder( itemCount: client.resourceNames.length, itemBuilder: (_, index) { final resourceName = _sortedResourceNames[index]; return ListTile( title: Text(resourceName.name), subtitle: Text( '${resourceName.namespace}:${resourceName.type}:${resourceName.subtype}'), onTap: () => _navigate(resourceName), trailing: _isNavigable(resourceName) ? Icon(Icons.chevron_right) : SizedBox.shrink(), ); })); } } ``` ### C++ ```cpp #include #include #include #include #include #include #include #include #include #include #include using namespace viam::sdk; using std::cerr; using std::cout; using std::endl; void move_in_square(std::shared_ptr base) { for (int i = 0; i < 4; ++i) { cout << "Move straight" << endl; // Move the base forward 600mm at 500mm/s base->move_straight(500, 500); cout << "Spin" << endl; // Spin the base by 90 degree at 100 degrees per second base->spin(90, 100); } } int main() { // Every Viam C++ SDK program must have one and only one Instance object which is created // before // any other C++ SDK objects and stays alive until all Viam C++ SDK objects are destroyed. Instance inst; // TODO: Replace "" with address from the CONNECT tab. std::string host(""); DialOptions dial_opts; // TODO: Replace "" with your machine's API key ID dial_opts.set_entity(std::string("")); // TODO: Replace "" with your machine's API key Credentials credentials("api-key", ""); dial_opts.set_credentials(credentials); boost::optional opts(dial_opts); Options options(0, opts); auto machine = RobotClient::at_address(host, options); std::cout << "Resources:\n"; for (const Name& resource : machine->resource_names()) { std::cout << "\t" << resource << "\n"; } std::string base_name("viam_base"); cout << "Getting base: " << base_name << endl; std::shared_ptr base; try { base = machine->resource_by_name(base_name); move_in_square(base); } catch (const std::exception& e) { cerr << "Failed to find " << base_name << ". Exiting." << endl; throw; } return EXIT_SUCCESS; } ```