Start from zero: the tools, the robot project and your first edit

This page is for you if you have never built an FTC robot program in Java. It needs no Java. At the end you have Android Studio, the robot project, a first program on the robot, and one safe edit. Then the Quick start is the next page (used Blocks before? From Blocks to Java first).

You need: a laptop (Mac or Windows) with internet, a Control Hub, a Driver Station (see below), and a USB cable for the Control Hub. Time: 45 to 60 minutes, most of it waiting for downloads.

Done already? If Android Studio opens your team’s robot project and it builds, go to the Quick start.

1. The pieces and their names

These words are on every page of these docs.

• Control Hub: the robot’s computer (made by REV). The motors, servos and sensors plug into it. It runs the Robot Controller app, and your code is part of that app.
• Driver Station: the app the drive team uses to pick a program and start it. The gamepads plug into the device that runs it. A Driver Hub is the REV device that runs the Driver Station app (an Android phone can run it too). These docs say “Driver Station”.
• Robot configuration: the list of motors, servos and sensors on the robot, each with a name, for example front_left or intake. You make it on the Driver Station, and it is saved on the Control Hub. Why it matters: your code finds each part by its name, so the names in the code must be exactly the same (capitals count).
• OpMode: one program you pick on the Driver Station. A robot project has many OpModes: one to drive, one or more autonomous ones, some test ones.
• TeleOp and Autonomous: the two kinds of OpMode. A TeleOp is driven by people with gamepads. An Autonomous runs on its own, with no gamepads, at the start of the match.
• INIT, START and STOP: the buttons on the Driver Station. INIT gets the OpMode ready (nothing may move yet). START begins it. STOP ends it.

2. Install Android Studio and get the robot project

Android Studio is the program you write and build the robot code in.

1. Download Android Studio from developer.android.com/studio and install it with the normal settings. Which version: FTC SDK 12.0 (the 2026-27 robot software) needs Android Studio Narwhal 3 Feature Drop or newer. The newest version from that page is fine.

2. Open Android Studio once. Let it finish its first setup (it downloads the Android SDK, the tools that make Android apps). Accept the normal choices.

3. Get the robot project: the folder of code that becomes the Robot Controller app. It is called FtcRobotController. Pick one way:

   • A. Your team already has one on GitHub (the usual way). Ask your mentor or code lead for its address. In Android Studio: File > New > Project from Version Control. Paste the address. Pick a folder on your laptop. Click Clone. (“Clone” means copy the project, with its history, from GitHub to your laptop.) Why: everyone on the team then works on the same code. The library may already be in it: if a mentor added it, there is an ftc-helper-lib folder next to TeamCode. If that folder is empty, Android Studio did not get it: in the Terminal (section 6), type git submodule update --init and press Enter. Why: the library is a submodule (a project kept inside another project), and a clone does not always fetch it (Add it to a project).
   • B. No team project yet. Download FTC’s project from github.com/FIRST-Tech-Challenge/FtcRobotController. Use the SDK 12.0 version: open Releases on that page, pick v12.0, and download the source code .zip. Unzip it. In Android Studio: File > Open, and pick the unzipped folder. Why 12.0: it is the version this library is built and tested with.

4. Open the project folder: the top folder, the one that has TeamCode and FtcRobotController inside it. Why: Android Studio needs the whole project, not only the TeamCode folder.

5. Wait for the first Gradle sync. Gradle is the tool that builds the app. The first time, it downloads a lot. A progress bar is at the bottom right. It can take 5 to 20 minutes. It is done when the bar is gone and the Build tab (bottom of the window) says the sync finished. Why wait: until the sync is done, Android Studio shows many false red errors.

6. Find TeamCode. On the left is the Project panel. At its top is a list: pick Project (not “Android”). Then open these folders, one in another:

   TeamCode/src/main/java/org/firstinspires/ftc/teamcode/

   This is where your team’s code goes. Every file you add in these docs goes in this folder (or in a folder inside it). (In the “Android” view the same folder shows as TeamCode > java > org.firstinspires.ftc.teamcode.)

3. First build and install

1. Build: click the green hammer at the top of the window (Build > Make Project). Wait for the Build tab to say it finished, with no errors. Why: this checks that the project builds on your laptop before you change anything.
2. Connect to the Control Hub. Turn on the robot. Then pick one:
   • USB (the easiest): a USB cable from the laptop to the Control Hub’s USB-C port.
   • Wi-Fi: join the laptop to the Control Hub’s Wi-Fi network (the one the Driver Station uses; ask your mentor for its name and password). Then, in the Terminal (section 6), type adb connect 192.168.43.1:5555. If it says adb is not found, use USB.
3. Pick the hub. At the top of the window is a list of devices. After a few seconds it shows the Control Hub (its name starts with REV Robotics). Pick it.
4. Install: click the green Run triangle next to it. The run list next to it must say TeamCode. It builds again, then installs the Robot Controller app on the Control Hub. Why: the robot runs the app that is on the hub, not the code on your laptop. After each change you click Run again.
5. Check on the Driver Station. It connects to the robot and shows the OpMode lists (the TeleOp list and the Autonomous list).
   • Your team’s project already has OpModes? Ask your code lead which one moves nothing (a test OpMode, for example), then press INIT, START, then STOP. Not sure? Skip this: in section 5 you install Concept: NullOp, a program that moves nothing.
   • FTC’s new project shows empty lists: its sample OpModes are hidden. You run your first one in section 5 below.

4. Reading Java without writing it

You do not need to write Java yet. You need to read it well enough to change one line safely. Here is a small file, the FTC sample ConceptNullOp.java, shortened:

package org.firstinspires.ftc.robotcontroller.external.samples;

import com.qualcomm.robotcore.eventloop.opmode.Disabled;
import com.qualcomm.robotcore.eventloop.opmode.OpMode;
import com.qualcomm.robotcore.eventloop.opmode.TeleOp;

@TeleOp(name = "Concept: NullOp", group = "Concept")
@Disabled
public class ConceptNullOp extends OpMode {

  @Override
  public void init() {
    telemetry.addData("Status", "Initialized");   // a line on the Driver Station
  }
  ...
}

What each part is:

• A file holds one class (one piece of a program). The file name and the class name are the same: ConceptNullOp.java holds class ConceptNullOp.
• The package line (the first line) says which folder the file is in, with dots in place of slashes. It must match the folder, or the file does not build.
• import lines name code from other places that this file uses (here, from the FTC SDK).
• @TeleOp(...) and @Disabled are notes for the Driver Station. @TeleOp(name = "...") is the name in the TeleOp list. @Disabled hides the OpMode from the list.
• { and } (curly brackets) hold a group of lines together. Every { has its own } further down. The class has one pair; each part inside it has its own pair.
• ; (semicolon) ends a statement (one command), like a full stop ends a sentence.
• // starts a comment: words for people, from // to the end of the line. Java ignores them.
• "text in quotes" is text, used as it is (a name on the Driver Station, a motor name). Words without quotes are names in the code (telemetry, init). Do not add or remove quotes.
• Capitals count. Intake, intake and INTAKE are three different names to Java.

Red text is an error. A name underlined in red, or a red line in the Build tab, is an error. Read only the first error: the later ones often come from the first. It looks like this:

Robot.java:12: error: ';' expected

That says: the file (Robot.java), the line number (12), and the problem (a ; is missing). Click it to go to the line. Fix it, then build again. Why the first: one missing ; or } can make twenty more errors below it, and they all go away with the first fix.

Java words

These words are in the code and in these docs. One line each; you meet them again in the lessons.

• variable: a name that holds a value, like a box with a label. maxPower holds 0.4.
• double: a kind of variable that holds a number with a decimal point (0.4, 96). int holds a whole number (3).
• boolean: a kind of variable that holds only true or false (yes or no).
• true / false: the two answers to a yes/no question, for example “is the button pressed?”.
• method: a named list of commands, like a custom block. init() and buttons(...) are methods. The ( ) after the name hold its inputs.
• void: written before a method’s name when the method hands nothing back.
• return: hands a result back from a method, and ends the method.
• object: one thing the program made from a class, with its own values: your robot, its intake. robot.intake.in() asks the intake object to run its in method.
• public: other files may use this name. (private: only this file may.)
• static: belongs to the class itself, not to one object, so there is only one. In Tunables.java, public static double maxPower is one number the whole program shares.

5. Copy a file into TeamCode and change one line

Now run your own first OpMode: a copy of the FTC sample above. It needs no motors.

1. In the Project panel, find the sample: FtcRobotController/src/main/java/org/firstinspires/ftc/robotcontroller/external/samples/ConceptNullOp.java.

2. Click it, and copy it (Edit > Copy). Click the teamcode folder (section 2, step 6), and paste it (Edit > Paste). If Android Studio asks, click OK (keep the name). Why copy: never change FTC’s own files. Your team’s code lives only in TeamCode.

3. Open the copy (in teamcode). Change exactly one line, the first one:

   Before:

   package org.firstinspires.ftc.robotcontroller.external.samples;

   After:

   package org.firstinspires.ftc.teamcode;

   Why: the file is now in the teamcode folder, and the package line must match its folder. (Android Studio may change it for you when you paste. Check it anyway.)

4. Delete the whole line @Disabled. Why: with it, the Driver Station hides the OpMode.

5. Build (hammer), then Run (triangle) to install it.

6. On the Driver Station, pick Concept: NullOp in the TeleOp list. INIT: it shows Status: Initialized. START: it shows the run time. STOP.

Common mistakes:

• Two package lines, or a first line with a typo: the build says class, interface, or enum expected. The file must have exactly one package line, at the top.
• A deleted ; or }: the build says ';' expected or reached end of file while parsing. Press Edit > Undo until the file is as it was.

Make a new file or folder

Later pages say “make a file” or “make a folder”. This is how, in the Project panel (the Project view from section 2, step 6). Each kind is made a different way:

1. A new Java file (a class, for example HardwareCheck.java): right-click the teamcode folder, New > Java Class. Type the name without .java (HardwareCheck), pick Class, and press Enter. Android Studio writes the package line for you. Then replace everything in the new file with the whole file the page shows (select all with Edit > Select All, then paste), and check that the first line is still package org.firstinspires.ftc.teamcode;. Why: the file name must be the class name, and the package line must match the folder.
2. A Java folder (a folder of code, for example autos): right-click the teamcode folder, New > Package, and type autos (after the teamcode. that is already there). A file in it starts with package org.firstinspires.ftc.teamcode.autos;. Why “Package”: in Java, a folder of code is called a package.
3. A plain text file (not Java: for example local.properties or a scenario my-test.sim): right-click the folder it goes in, New > File, and type the full name with its ending (local.properties, my-test.sim). Do not add .txt. If Android Studio asks what kind of file it is (“Register New File Type Association”), pick Text. Why the full name: the ending tells the tools what the file is; my-test.sim.txt is not found.
4. A plain folder (not Java: for example simulator/scenarios next to TeamCode): right-click the top project folder (the one with TeamCode in it), New > Directory, and type simulator/scenarios. The / makes a folder inside a folder.

The Quick start puts the autonomous programs in a Java folder autos inside teamcode (kind 2).

6. The Terminal tab

Some steps in these docs are commands you type. You type them in Android Studio’s Terminal.

1. Open it: the Terminal tab at the bottom of the window (or View > Tool Windows > Terminal).
2. Where it starts: in the project folder, the one with TeamCode and FtcRobotController in it. The text before the cursor (the prompt) shows the folder’s name.
3. cd (“change directory”) goes into a folder: cd ftc-helper-lib. cd .. goes back up one folder. The library’s commands (the simulator, the file maker) run inside ftc-helper-lib. No ftc-helper-lib folder yet? It is there only after the library was added to the project (Add it to a project, the Quick start’s step 1). With FTC’s new project (way B), it is not there until you do that step.
4. Run one command: type it (or paste it), press Enter, and wait for the prompt to come back. Run one line at a time.
5. Gradle commands print a lot (./gradlew ...). The first one downloads for a few minutes. Look at the last lines: BUILD SUCCESSFUL is good; BUILD FAILED comes with the first problem just above * What went wrong:. Warnings are not errors. These are normal and safe to ignore: source value 8 is obsolete, Java compiler version 21 has deprecated support for compiling with source/target version 8, SDK processing. This version only understands SDK XML versions up to 3, Deprecated Gradle features were used, [Incubating] Problems report.
6. Stop a running command with Ctrl+C (on a Mac too). Some commands keep running on purpose: the simulator (./gradlew :sim:run) is a small server that runs until you stop it.
7. Windows: type .\gradlew (PowerShell) or gradlew.bat instead of ./gradlew.

The library’s commands also need a one-time laptop setup (where Java and the Android SDK are): Quick start: Laptop setup.

7. Git in two sentences

A commit saves a snapshot of your changes on your laptop, with a short note about what changed (Git > Commit in Android Studio), and a push sends your commits to the team’s GitHub so everyone gets them (Git > Push). Commit after each thing that works; ask your code lead before you push to the team’s main branch (the team’s shared copy of the code, the one everyone builds from).

The library itself: a mentor or code lead usually adds it to the robot project once, for the whole team (Add it to a project, about 10 minutes). After that, everyone who clones the project gets it.

Next

1. Used Scratch or Blocks before? Read From Blocks to Java next, before the Quick start: it shows where each block you know went.
2. Quick start: get the five robot files, change the lines marked STEP, and drive.
3. Lesson 1: the robot in five files, then lessons 2 to 7 of the main track.