FTC Programming with Android Studioftckickoff.allendalerobotics.com/wp-content/... · David Austin FTC Programming with Android Studio. LinearOpMode In a LinearOpMode, you do not

FTC advanced programmingwith Android Studio

David Austin

Allendale Robotics

HexaSonics, FTC Team 7023

[email protected]

David Austin FTC Programming with Android Studio

OpModes

Most of the programming team’s effort is in writing OpModes.

OpModes extend OpMode as in

public class AmazingAuto extends OpMode

You must register OpModes with the app by including anannotation:

@Autonomous(name="Amazing auto!", group="Wow")// @Disabledpublic class AmazingAuto extends OpMode

You may also extend LinearOpMode.


OpModes








OpModes








The life cycle of an OpMode

OpModes operate within an event driven model. The codeexecutes in roughly 25 ms cycles. Whatever you do in onecycle has to finish within that time interval.There are a number of methods you need to construct to definean OpMode.

init(): Called once after Init is pressed.

init loop(): Called every 25 milliseconds after Init ispressed.start(): This is executed once after you press the Startbutton on the Driver Station.loop(): While the opmode is running, this method isexecuted roughly every 25 milliseconds.stop(): Instructions to perform when the Stop button ispressed; e.g. set the power of all the motors to zero.




init(): Called once after Init is pressed.init loop(): Called every 25 milliseconds after Init ispressed.

start(): This is executed once after you press the Startbutton on the Driver Station.loop(): While the opmode is running, this method isexecuted roughly every 25 milliseconds.stop(): Instructions to perform when the Stop button ispressed; e.g. set the power of all the motors to zero.




init(): Called once after Init is pressed.init loop(): Called every 25 milliseconds after Init ispressed.start(): This is executed once after you press the Startbutton on the Driver Station.

loop(): While the opmode is running, this method isexecuted roughly every 25 milliseconds.stop(): Instructions to perform when the Stop button ispressed; e.g. set the power of all the motors to zero.




init(): Called once after Init is pressed.init loop(): Called every 25 milliseconds after Init ispressed.start(): This is executed once after you press the Startbutton on the Driver Station.loop(): While the opmode is running, this method isexecuted roughly every 25 milliseconds.

stop(): Instructions to perform when the Stop button ispressed; e.g. set the power of all the motors to zero.




init(): Called once after Init is pressed.init loop(): Called every 25 milliseconds after Init ispressed.start(): This is executed once after you press the Startbutton on the Driver Station.loop(): While the opmode is running, this method isexecuted roughly every 25 milliseconds.stop(): Instructions to perform when the Stop button ispressed; e.g. set the power of all the motors to zero.



These are the methods you will mainly use:

init(): Load the robot configuration into your code.DcMotor leftDrive =

hardwareMap.dcMotor.get(‘‘leftDrive’’);

loop(): This is the main part of your code. You will listento sensors, determine how to respond, and set powerlevels to motors.stop(): Turn everything off.leftDrive.setPower(0);






loop(): This is the main part of your code. You will listento sensors, determine how to respond, and set powerlevels to motors.

stop(): Turn everything off.leftDrive.setPower(0);






loop(): This is the main part of your code. You will listento sensors, determine how to respond, and set powerlevels to motors.stop(): Turn everything off.leftDrive.setPower(0);


The problem

What do you do when you want to combine a couple ofseparate actions?

Drive forward 50 inches.Turn on shooter motors.Turn on shooter feed mechanism.


The problem


Drive forward 50 inches.

Turn on shooter motors.Turn on shooter feed mechanism.


The problem


Drive forward 50 inches.Turn on shooter motors.

Turn on shooter feed mechanism.


The problem


Drive forward 50 inches.Turn on shooter motors.Turn on shooter feed mechanism.


Two solutions

There are two solutions to this problem.

Write your code in a class extending LinearOpMode,which itself extends OpMode.

Pros: You write sequential code:do A, then B, then C, ...

Cons: It feels like a hack (because it is).Just extend OpMode and use a state machine to keep trackof the actions.

Pros: Good opportunity to learn an important computerscience paradigm

Cons: See Pros.


Two solutions




Cons: It feels like a hack (because it is).

Just extend OpMode and use a state machine to keep trackof the actions.


Cons: See Pros.


Two solutions







Cons: See Pros.


Two solutions







Cons: See Pros.


Two solutions






Cons: See Pros.


Two solutions






Cons: See Pros.


Two solutions






Cons: See Pros.


LinearOpMode

In a LinearOpMode, you do not override the usual methods,init(), loop(), etc.

Everything goes in one method

public class OurAuton extends LinearOpMode {public void runOpMode() {

do initialization stuff

waitForStart();

do task Ado task Bdo task C

}}


LinearOpMode

In a LinearOpMode, you do not override the usual methods,init(), loop(), etc.

Everything goes in one method

public class OurAuton extends LinearOpMode {public void runOpMode() {

do initialization stuff

waitForStart();

do task Ado task Bdo task C

}}


LinearOpMode

Example: Run a motor for 10 seconds

public void runOpMode() {DcMotor motor

= hardwareMap.dcMotor.get(‘‘motor’’);

waitForStart();

motor.setPower(1);sleep(10000);motor.setPower(0);

}


Motor run modes

Motors can be in one of four “run modes:”

RUN WITHOUT ENCODER: the setPower method does justthat. This is the default mode.STOP AND RESET ENCODER: this mode resets the motor’sencoder. Follow with an idle() command to allow timefor the reset.RUN TO POSITION: the setPower method causes themotor to drive to the desired encoder count, which is setwith setTargetPosition.RUN USING ENCODER: the setPower method causes themotor to turn at a specified percentage of its maximumspeed, which is set with setMaxSpeed.


Motor run modes


RUN WITHOUT ENCODER: the setPower method does justthat. This is the default mode.

STOP AND RESET ENCODER: this mode resets the motor’sencoder. Follow with an idle() command to allow timefor the reset.RUN TO POSITION: the setPower method causes themotor to drive to the desired encoder count, which is setwith setTargetPosition.RUN USING ENCODER: the setPower method causes themotor to turn at a specified percentage of its maximumspeed, which is set with setMaxSpeed.


Motor run modes


RUN WITHOUT ENCODER: the setPower method does justthat. This is the default mode.STOP AND RESET ENCODER: this mode resets the motor’sencoder. Follow with an idle() command to allow timefor the reset.

RUN TO POSITION: the setPower method causes themotor to drive to the desired encoder count, which is setwith setTargetPosition.RUN USING ENCODER: the setPower method causes themotor to turn at a specified percentage of its maximumspeed, which is set with setMaxSpeed.


Motor run modes


RUN WITHOUT ENCODER: the setPower method does justthat. This is the default mode.STOP AND RESET ENCODER: this mode resets the motor’sencoder. Follow with an idle() command to allow timefor the reset.RUN TO POSITION: the setPower method causes themotor to drive to the desired encoder count, which is setwith setTargetPosition.

RUN USING ENCODER: the setPower method causes themotor to turn at a specified percentage of its maximumspeed, which is set with setMaxSpeed.


Motor run modes


RUN WITHOUT ENCODER: the setPower method does justthat. This is the default mode.STOP AND RESET ENCODER: this mode resets the motor’sencoder. Follow with an idle() command to allow timefor the reset.RUN TO POSITION: the setPower method causes themotor to drive to the desired encoder count, which is setwith setTargetPosition.RUN USING ENCODER: the setPower method causes themotor to turn at a specified percentage of its maximumspeed, which is set with setMaxSpeed.


Hardware

Encapsulate your hardware into a single class that can beshared between OpModes. Easy to maintain and reuse.

public void Robot() {DcMotor motor;public Robot(HardwareMap hardwaremap) {

motor = hardwareMap.dcMotor.get(‘‘motor’’);}public void setMotorPower(double power) {

motor.setPower(power);}public double getMotorPosition() {

return motor.getCurrentPosition();}

}


Hardware

Instantiate and reference from within your OpModes.

public void runOpMode() {

Robot robot = new Robot(hardwareMap);waitForStart();robot.setMotorPower(1);while (isOpModeActive() &&

robot.getMotorPosition() < 5000) {telemetry.addData(‘‘Motor: ‘‘,

robot.getMotorPosition());telemetry.update();

}robot.setMotorPower(0);

}


State machine

An alternative to LinearOpModes:

Mimic FRC’s command-based programming paradigm. Createan interface BasicCommand with methods

public void init()

public void execute()

public boolean isFinished()

public void stop()

Create commands to perform specific actions, such asDriveForward(double inches).


State machine



public void init()



public void stop()



State machine



public void init()



public void stop()



State machine



public void init()



public void stop()



State machine



public void init()



public void stop()



State machine



public void init()



public void stop()



State machine

Create an OpMode as a list of BasicCommands. At any onetime, there is a currentCommand.

Within the loop() method, we are in of four states:INIT, EXECUTE, STOP, DONE

State machine:

INIT: initialize currentCommand and go to EXECUTE

EXECUTE: execute currentCommand. IfcurrentCommand.isFinished(), go to STOP.STOP: stop currentCommand. If there is anothercommand, go to INIT. If not, go to DONE

DONE: just relax.


State machine



State machine:INIT: initialize currentCommand and go to EXECUTE


DONE: just relax.


State machine




EXECUTE: execute currentCommand. IfcurrentCommand.isFinished(), go to STOP.

STOP: stop currentCommand. If there is anothercommand, go to INIT. If not, go to DONE

DONE: just relax.


State machine





DONE: just relax.


State machine





DONE: just relax.


Resources

Resources:FTC resources:https://www.firstinspires.org/node/5291

Github repository:https://github.com/ftctechnh/ftc app

User’s manual:https://github.com/ftctechnh/ftc app/releases

FTC Control System Wiki:https://github.com/ftctechnh/ftc app/wiki

David Austin: [email protected]


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FTC Programming with Android Studioftckickoff.allendalerobotics.com/wp-content/... · David Austin FTC Programming with Android Studio. LinearOpMode In a LinearOpMode, you do not