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Examples

Examples are provided in the form of code (either Java or Blockly) that must be added to an OpMode. Click an example's dropdown to see its contents.

OpModes

Each example will use the following OpModes. For the sake of brevity, these are not repeated for each example. If an example mentions 'Control', then it must use the TeleOp OpMode. If it mentions 'Command', then it is primarily intended for use in Autonomous, but command() can be used in TeleOp as well. If neither term is used, then the OpMode type doesn't matter (and if no 'Methods' section is included, then either command() or control() can be used).

TeleOp

package org.firstinspires.ftc.teamcode;

import com.qualcomm.robotcore.eventloop.opmode.LinearOpMode;
import com.qualcomm.robotcore.eventloop.opmode.TeleOp;
// Imports

@TeleOp(name="Tele", group="dev")
public class Tele extends LinearOpMode {
    // Additional

    @Override
    public void runOpMode() {
        // Construction

        waitForStart();
        while (opModeIsActive()) {
            // Methods
        }
    }
}

Autonomous

package org.firstinspires.ftc.teamcode;

import com.qualcomm.robotcore.eventloop.opmode.LinearOpMode;
import com.qualcomm.robotcore.eventloop.opmode.Autonomous;
// Imports

@Autonomous(name="Auto", group="dev")
public class Auto extends LinearOpMode {
    // Additional

    @Override
    public void runOpMode() {
        // Construction

        waitForStart();
        if (opModeIsActive()) {
            // Methods
        }
    }
}

Note the locations of Imports, Additional, Construction, and Methods

Example Structure

  • Imports: classes and enums that must be imported
  • Additional: additional variables and objects that must be setup
  • Construction: easy-ftc object construction
  • Methods: easy-ftc methods called on constructed objects
  • Notes: any relevant details about using the example

Examples

Basic Use

Control of Motor Mechanism

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .gamepad(gamepad1)
    .build();

Methods

drive.control();

Notes

  • The power level of the mechanism can be scaled down (the default is full power)

    drive.control(0.3);

Command of Motor Mechanism

Imports

import org.edu_nation.easy_ftc.mechanism.Arm;

Construction

Arm arm = new Arm.Builder(this, hardwareMap)
    .build();

Methods

arm.command(Arm.Direction.UP, 2, 0.5);

Modify Motor Mechanism Attributes

Imports

import org.edu_nation.easy_ftc.mechanism.Lift;
import com.qualcomm.robotcore.hardware.DcMotor;

Construction

Lift lift = new Lift.Builder(this, hardwareMap)
    .count(2)                                     // use two motors for this mechanism
    .names(new String[]{"liftLeft", "newName"})   // change the names of the motors
    .reverse()                                    // reverse all motors in the mechanism
    .reverse("liftLeft")                          // reverse specific motor
    .reverse(new String[]{"liftLeft", "newName"}) // reverse multiple specific motors
    .behavior(DcMotor.ZeroPowerBehavior.FLOAT)    // change the zero-power behavior of the motors
    .build();

Control of Servo Mechanism

Imports

import org.edu_nation.easy_ftc.mechanism.Claw;

Construction

Claw claw = new Claw.Builder(this, hardwareMap)
    .gamepad(gamepad1)
    .build();

Methods

claw.control();

Command of Servo Mechanism

Imports

import org.edu_nation.easy_ftc.mechanism.Claw;

Construction

Claw claw = new Claw.Builder(this, hardwareMap)
    .build();

Methods

claw.command(Claw.Direction.CLOSE);

Modify Servo Mechanism Attributes

Imports

import org.edu_nation.easy_ftc.mechanism.Claw;

Construction

Claw claw = new Claw.Builder(this, hardwareMap)
    .count(2)                                     // use two servos for this mechanism
    .names(new String[]{"clawLeft", "newName"})   // change the names of the servos
    .reverse()                                    // reverse all servos in the mechanism
    .reverse("clawLeft")                          // reverse specific servo
    .reverse(new String[]{"clawLeft", "newName"}) // reverse multiple specific servos
    .open(0.8).close(0.2)                         // adjust open and close positions
    .delay(3)                                     // adjust the delay for non-smooth movement
    .build();

Read and Display Sensor State

Imports

import org.edu_nation.easy_ftc.sensor.Touch;

Construction

Touch touch = new Touch.Builder(hardwareMap)
    .build();

Methods

telemetry.addData("Touch: ", touch.state());
telemetry.update();

Modify Sensor Attributes

Imports

import org.edu_nation.easy_ftc.sensor.Distance;

Construction

Distance distance = new Distance.Builder(hardwareMap)
    .name("distanceSensor") // change the name of the sensor
    .reverse()              // reverse the sensor state
    .threshold(6.0)         // change the distance threshold
    .build();

Enable Features

Encoder: Velocity-Based Control

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .encoder()
    .gamepad(gamepad1)
    .build();

Methods

drive.control();

Notes

  • Unlike command(), adding .diameter() doesn't affect control(), so velocity will be used either way so long as .encoder() is enabled

Encoder: Time-Based Command

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .encoder()
    .build();

Methods

// moves forward for 2 seconds at half velocity
drive.command(Drive.Direction.FORWARD, 2, 0.5);

Encoder: Distance-Based Command

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .encoder().diameter(4).gearing(19.2)
    .build();

Methods

// moves forward for 12 inches at half power
drive.command(Drive.Direction.FORWARD, 12, 0.5);

Notes

  • The distance unit used in command() will be the same as what's used in .diameter()
  • .gearing() is optional here, but correcting it can improve accuracy

Encoder: Limits Using Ticks

Imports

import org.edu_nation.easy_ftc.mechanism.Lift;

Construction

Lift lift = new Lift.Builder(this, hardwareMap)
    .encoder().up(300).down(-300)
    .gamepad(gamepad1)  // only needed for teleop
    .build();

Encoder: Limits Using Distance

Imports

import org.edu_nation.easy_ftc.mechanism.Lift;

Construction

Lift lift = new Lift.Builder(this, hardwareMap)
    .encoder().diameter(2).gearing(60).up(3).down(-3)
    .gamepad(gamepad1)  // only needed for teleop
    .build();

Notes

  • .gearing() is optional here, but correcting it can improve accuracy

Gyro: Angle-Based Command

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;
import org.firstinspires.ftc.robotcore.external.navigation.AngleUnit;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .gamepad(gamepad1)  // only needed for teleop
    .build();

Methods

drive.command(Drive.Direction.ROTATE_LEFT, 90, 0.2, AngleUnit.DEGREES);

Notes

  • AngleUnit.RADIANS can be used as well

Smooth Servo

Imports

import org.edu_nation.easy_ftc.mechanism.Claw;

Construction

Claw claw = new Claw.Builder(this, hardwareMap)
    .smooth()
    .gamepad(gamepad1)  // only needed for teleop
    .build();

Notes

  • The increment and incrementDelay can be adjusted if you'd like to change the 'smoothness' and/or speed

    Claw claw ...
    .smooth().increment(0.04).incrementDelay(0.01)
    ...

Arcade Drive Control

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;
import org.edu_nation.easy_ftc.mechanism.Drive.Layout;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .layout(Layout.ARCADE)
    .gamepad(gamepad1)
    .build();

Methods

drive.control();

Mecanum Drive

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .type(Drive.Type.MECANUM)
    .gamepad(gamepad1)  // only needed for teleop
    .build();

Field-Centric Mecanum Drive

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;
import org.edu_nation.easy_ftc.mechanism.Drive.Layout;

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .type(Drive.Type.MECANUM).layout(Layout.FIELD)
    .gamepad(gamepad1)  // only needed for teleop
    .build();

Notes

  • LogoFacingDirection and UsbFacingDirection can be changed if field-centric movement is offset

    Drive drive ...
    .logo(LogoFacingDirection.DOWN).usb(UsbFacingDirection.BACKWARD)
    ...

Control of Motor Mechanism with Gamepad Deadzone

Imports

import org.edu_nation.easy_ftc.mechanism.Lift;

Construction

Lift lift = new Lift.Builder(this, hardwareMap)
    .gamepad(gamepad1).deadzone(0.1)
    .build();

Methods

lift.control();

Notes

  • .deadzone() only affects mechanisms using either Joysticks or Triggers (Drive and Lift)

Advanced Use

Control with Command Sequence

Imports

import org.edu_nation.easy_ftc.mechanism.Claw;
import org.edu_nation.easy_ftc.mechanism.Drive;
import org.edu_nation.easy_ftc.mechanism.CommandSequence;
import org.firstinspires.ftc.robotcore.external.navigation.AngleUnit;

Construction

// Hardware init
Drive drive = new Drive.Builder(this, hardwareMap)
    .gamepad(gamepad1)
    .build();
Claw claw = new Claw.Builder(this, hardwareMap)
    .gamepad(gamepad1)
    .build();

// Create the sequence
CommandSequence sequence = new CommandSequence()
    .command(drive, Drive.Direction.ROTATE_LEFT, 90, 0.2, AngleUnit.DEGREES)
    .command(drive, Drive.Direction.FORWARD, 2, 0.2)
    .command(claw, Claw.Direction.OPEN)
    .command(drive, Drive.Direction.BACKWARD, 2, 0.2)
    .command(drive, Drive.Direction.ROTATE_RIGHT, 90, 0.2, AngleUnit.DEGREES);

Methods

// normal drivetrain and claw control
drive.control();
claw.control();

// control the sequence
sequence.control();

Notes

  • Sequence is initiated by pressing dpad_right and can be interrupted with dpad_left
  • Holding down dpad_left works best since the loop used by command() is thread blocking, meaning its value is only read between sequence states

Control with Custom Command Sequence

Imports

import org.edu_nation.easy_ftc.mechanism.Drive;

Additional

public enum State {
    ROTATE_LEFT, ROTATE_RIGHT
}

Construction

Drive drive = new Drive.Builder(this, hardwareMap)
    .gamepad(gamepad1)
    .build();

// define the starting state
State state = State.ROTATE_LEFT;

Methods

// state machine
switch (state) {
    case ROTATE_LEFT:
        // initiate sequence when dpad_right is pressed
        if (gamepad1.dpad_right) {
            drive.command(Drive.Direction.ROTATE_LEFT, 2, 0.5);
            state = State.ROTATE_RIGHT;
        }
        break;
    case ROTATE_RIGHT:
        drive.command(Drive.Direction.ROTATE_RIGHT, 2, 0.5);
        // restart the sequence once final state is completed
        state = State.ROTATE_LEFT;
        break;
    default:
        state = State.ROTATE_LEFT;
}

// terminate sequence when dpad_left is pressed
if (gamepad1.dpad_left) {
    state = State.ROTATE_LEFT;
}

// normal drivetrain control
drive.control();

Notes

  • CommandSequence should be used for most routines, but additional options are available if you roll your own state-machine (e.g., sensor integration)
  • Sequence is initiated by pressing dpad_right and can be interrupted with dpad_left
  • Holding down dpad_left works best since the loop used by command() is thread blocking, meaning its value is only read between sequence states

TeleOp
TeleOp

Autonomous
Autonomous

Note the locations of Additional and Methods

MyBlocks

As Blockly doesn't yet allow the import of non-static, external Java classes, any changes to Imports and Construction must be done in a subsystem's associated MyBlock file rather than the Blockly OpModes above. An abridged form of Arm's MyBlock file is included below, but the exact MyBlock file used will be the one associated with the given subsystem (so if an example is using the Drive subsystem, any changes to Imports or Construction will be made in Drive.java).

TeleOp

package org.firstinspires.ftc.teamcode;

import org.firstinspires.ftc.robotcore.external.BlocksOpModeCompanion;
import org.firstinspires.ftc.robotcore.external.ExportToBlocks;
import org.edu_nation.easy_ftc.mechanism.Arm.Direction;
// Imports

public class Arm extends BlocksOpModeCompanion {
    @ExportToBlocks(comment = "Initiate an automated arm movement",
            parameterLabels = {"Direction", "Time", "Power"})
    public static void command(Direction direction, double time, double power) {
        org.edu_nation.easy_ftc.mechanism.Arm arm =
                new org.edu_nation.easy_ftc.mechanism.Arm.Builder(linearOpMode, hardwareMap)
                        .build();
        arm.command(direction, time, power);
    }

    @ExportToBlocks(
            comment = "Enable teleoperated arm movement with gamepad (lb, rb) at the specified power",
            parameterLabels = {"Power"})
    public static void control(double power) {
        // Construction
        arm.control(power);
    }

    @ExportToBlocks(
            comment = "Enable teleoperated arm movement with gamepad (lb, rb) at a power of 0.5")
    public static void control() {
        // Construction
        arm.control();
    }

    // Direction methods ...
}

Autonomous

package org.firstinspires.ftc.teamcode;

import org.firstinspires.ftc.robotcore.external.BlocksOpModeCompanion;
import org.firstinspires.ftc.robotcore.external.ExportToBlocks;
import org.edu_nation.easy_ftc.mechanism.Arm.Direction;
// Imports

public class Arm extends BlocksOpModeCompanion {
    @ExportToBlocks(comment = "Initiate an automated arm movement",
            parameterLabels = {"Direction", "Time", "Power"})
    public static void command(Direction direction, double time, double power) {
        // Construction
        arm.command(direction, time, power);
    }

    @ExportToBlocks(
            comment = "Enable teleoperated arm movement with gamepad (lb, rb) at the specified power",
            parameterLabels = {"Power"})
    public static void control(double power) {
        org.edu_nation.easy_ftc.mechanism.Arm arm =
                new org.edu_nation.easy_ftc.mechanism.Arm.Builder(linearOpMode, hardwareMap)
                        .gamepad(gamepad1).build();
        arm.control(power);
    }

    @ExportToBlocks(
            comment = "Enable teleoperated arm movement with gamepad (lb, rb) at a power of 0.5")
    public static void control() {
        org.edu_nation.easy_ftc.mechanism.Arm arm =
                new org.edu_nation.easy_ftc.mechanism.Arm.Builder(linearOpMode, hardwareMap)
                        .gamepad(gamepad1).build();
        arm.control();
    }

    // Direction methods ...
}

Note the locations of Imports and Construction

Example Structure

  • Imports: classes and enums that must be imported
  • Additional: additional variables and objects that must be setup
  • Construction: easy-ftc object construction
  • Methods: easy-ftc methods called on constructed objects
  • Notes: any relevant details about using the example

Examples

Basic Use

Control of Motor Mechanism

Methods


Control Motor

Notes

  • The power level of the mechanism can be scaled down (the default is full power)


    Control Multiplier

Command of Motor Mechanism

Methods


Command Motor

Modify Motor Mechanism Attributes

Imports

import com.qualcomm.robotcore.hardware.DcMotor;

Construction

org.edu_nation.easy_ftc.mechanism.Lift lift =
        new org.edu_nation.easy_ftc.mechanism.Lift.Builder(linearOpMode, hardwareMap)
                .count(2)                                     // use two motors for this mechanism
                .names(new String[]{"liftLeft", "newName"})   // change the names of the motors
                .reverse()                                    // reverse all motors in the mechanism
                .reverse("liftLeft")                          // reverse specific motor
                .reverse(new String[]{"liftLeft", "newName"}) // reverse multiple specific motors
                .behavior(DcMotor.ZeroPowerBehavior.FLOAT)    // change the zero-power behavior of the motors
                .build();

Control of Servo Mechanism

Methods


Control Servo

Command of Servo Mechanism

Methods


Command Servo

Modify Servo Mechanism Attributes

Construction

org.edu_nation.easy_ftc.mechanism.Claw claw =
        new org.edu_nation.easy_ftc.mechanism.Claw.Builder(linearOpMode, hardwareMap)
                .count(2)                                     // use two servos for this mechanism
                .names(new String[]{"clawLeft", "newName"})   // change the names of the servos
                .reverse()                                    // reverse all servos in the mechanism
                .reverse("clawLeft")                          // reverse specific servo
                .reverse(new String[]{"clawLeft", "newName"}) // reverse multiple specific servos
                .open(0.8).close(0.2)                         // adjust open and close positions
                .delay(3)                                     // adjust the delay for non-smooth movement
                .build();

Read and Display Sensor State

Methods


Display State

Modify Sensor Attributes

Construction

org.edu_nation.easy_ftc.sensor.Distance distance =
        new org.edu_nation.easy_ftc.sensor.Distance.Builder(hardwareMap)
                .name("distanceSensor") // change the name of the sensor
                .reverse()              // reverse the sensor state
                .threshold(6.0)         // change the distance threshold
                .build();

Enable Features

As an easy-ftc object must be constructed for every Blockly function call, these objects are unable to persist their state, which breaks the following features for Blockly users:

  • Encoder limits in control()
  • Field-centric driving

If these features are must-haves, use Java instead.

Encoder: Velocity-Based Control

Construction

org.edu_nation.easy_ftc.mechanism.Drive drive =
        new org.edu_nation.easy_ftc.mechanism.Drive.Builder(linearOpMode, hardwareMap)
                .encoder()
                .gamepad(gamepad1)
                .build();

Methods


Control Motor

Notes

  • Unlike command(), adding .diameter() doesn't affect control(), so velocity will be used either way so long as .encoder() is enabled

Encoder: Time-Based Command

Construction

org.edu_nation.easy_ftc.mechanism.Drive drive =
        new org.edu_nation.easy_ftc.mechanism.Drive.Builder(linearOpMode, hardwareMap)
                .encoder()
                .build();

Methods


Command Velocity

Encoder: Distance-Based Command

Construction

org.edu_nation.easy_ftc.mechanism.Drive drive =
        new org.edu_nation.easy_ftc.mechanism.Drive.Builder(linearOpMode, hardwareMap)
                .encoder().diameter(4).gearing(19.2)
                .build();

Methods


Command Distance

Notes

  • The distance unit used in command() will be the same as what's used in .diameter()
  • .gearing() is optional here, but correcting it can improve accuracy
  • The Time parameterLabel in Drive.command() has been changed to Distance here. This is optional, but it clarifies the intended functionality for Blockly users

Encoder: Command Limits Using Ticks

Construction

org.edu_nation.easy_ftc.mechanism.Lift lift =
        new org.edu_nation.easy_ftc.mechanism.Lift.Builder(linearOpMode, hardwareMap)
                .encoder().up(300).down(-300)
                .build();

Methods


Limits Ticks

Encoder: Command Limits Using Distance

Construction

org.edu_nation.easy_ftc.mechanism.Lift lift =
        new org.edu_nation.easy_ftc.mechanism.Lift.Builder(linearOpMode, hardwareMap)
                .encoder().diameter(2).gearing(60).up(3).down(-3)
                .build();

Methods


Limits Distance

Notes

  • .gearing() is optional here, but correcting it can improve accuracy
  • The Time parameterLabel in Lift.command() has been changed to Distance here. This is optional, but it clarifies the intended functionality for Blockly users

Gyro: Angle-Based Command

Methods


Command Gyro

Notes

  • AngleUnit.RADIANS can be used as well

Smooth Servo

Construction

org.edu_nation.easy_ftc.mechanism.Claw claw =
        new org.edu_nation.easy_ftc.mechanism.Claw.Builder(linearOpMode, hardwareMap)
                .smooth()
                .gamepad(gamepad1) // only needed for teleop
                .build();

Notes

  • The increment and incrementDelay can be adjusted if you'd like to change the 'smoothness' and/or speed

    org.edu_nation ...
        new org.edu_nation ...
                .smooth().increment(0.04).incrementDelay(0.01)
                ...

Arcade Drive Control

Imports

import org.edu_nation.easy_ftc.mechanism.Drive.Layout;

Construction

org.edu_nation.easy_ftc.mechanism.Drive drive =
        new org.edu_nation.easy_ftc.mechanism.Drive.Builder(linearOpMode, hardwareMap)
                .layout(Layout.ARCADE)
                .gamepad(gamepad1)
                .build();

Methods


Control Motor

Mecanum Drive

Construction

org.edu_nation.easy_ftc.mechanism.Drive drive =
        new org.edu_nation.easy_ftc.mechanism.Drive.Builder(linearOpMode, hardwareMap)
                .type(org.edu_nation.easy_ftc.mechanism.Drive.Type.MECANUM)
                .gamepad(gamepad1) // only needed for teleop
                .build();

Control of Motor Mechanism with Gamepad Deadzone

Construction

org.edu_nation.easy_ftc.mechanism.Lift lift =
        new org.edu_nation.easy_ftc.mechanism.Lift.Builder(linearOpMode, hardwareMap)
                .gamepad(gamepad1).deadzone(0.1)
                .build();

Methods


Control Deadzone

Notes

  • .deadzone() only affects mechanisms using either Joysticks or Triggers (Drive and Lift)

Advanced Use

Control with Command Sequence

Additional


Sequence

Methods


Control Sequence

Notes

  • Sequence is initiated by pressing dpad_right and can be interrupted with dpad_left
  • Holding down dpad_left works best since the loop used by command() is thread blocking, meaning its value is only read between sequence states

Control with Custom Command Sequence

Additional


Starting State

Methods


State Machine

Notes

  • CommandSequence should be used for most routines, but additional options are available if you roll your own state-machine (e.g., sensor integration)
  • Sequence is initiated by pressing dpad_right and can be interrupted with dpad_left
  • Holding down dpad_left works best since the loop used by command() is thread blocking, meaning its value is only read between sequence states