Programming Teleop
Configuration
Before getting started with programming we needed to create a configuration file. Below is an overview of how the robot is configured for the teleop code to function as expected:
| Port Type | Port Number | Device Type | Name |
|---|---|---|---|
Motor | 0 | REV Robotics Ultraplanetary HD Hex Motor | rightDrive |
Motor | 1 | REV Robotics Ultraplanetary HD Hex Motor | leftDrive |
Motor | 2 | REV Robotics Core Hex Motor | rightarm |
Motor | 3 | REV Robotics Core Hex Motor | leftarm |
Servo | 0 | Servo | wrist |
Servo | 1 | Servo | gripper |
Configuration file download
To put this configuration file on your robot, drag this file into the "FIRST" folder of your Control Hub's file system.
For more in-depth information on the configuration process check out Hello Robot - Configuration!
Wiring Diagram
| Device Name | Device Type | Port |
|---|---|---|
rightDrive | UltraPlanetary Gearbox Kit and HD Hex Motor | Motor/Encoder Port 0 |
leftDrive | UltraPlanetary Gearbox Kit and HD Hex Motor | Motor/Encoder Port 1 |
armright | Core Hex Motor | Motor/Encoder Port 2 |
armleft | Core Hex Motor | Motor/Encoder Port 3 |
wrist | Smart Robot Servo | Servo Port 0 |
gripper | Smart Robot Servo | Servo Port 1 |
Gamepad Setup
Items to consider when mapping out your gamepad:
What kind of input does the mechanism need?
Joysticks and Triggers input floating point data to your code allowing you to adjust the speed of a motor based on the pressure applied to the trigger or position of the joystick.
Buttons, Bumpers, and D-Pad provide boolean data to your code and are ideal for triggering an action such as rotating a motor to a set position.
What drivetrain are you using and what driving style do you want to use?
We decided our robot for CENTERSTAGE would be driven with Split Arcade Drive for advantages in precision while driving.
Which input makes the most sense?
There are multiple buttons in play for this year's Starter Bot. Both bumpers control the gripper's ability to pick up Pixels. The wrist servo is bound to the "A/Cross" and "B/Circle" buttons for rotating between the intake and home position. Lastly, this year's arm is controlled by the triggers.
Not all gamepads have buttons labeled the same way. Check the manufacturer's documentation for accurate button mapping.
2023-24 REV DUO FTC Starter Bot Gamepad Layout:
| Gamepad Input | Function |
|---|---|
Right Joystick | Turn Left and Right |
Left Joystick | Drive Forward and Reverse |
Right and/or Left Bumper | Gripper Close |
A/Cross | Arm & Wrist Move to Home Position
|
B/Circle | Arm & Wrist Move to Intake Position
|
Y/Triangle | Arm & Wrist Move to Scoring Position
|
Option | Zero Encoder for Arm |
Left Trigger | Lower Arm |
Right Trigger | Raise Arm |
More information on programming gamepads for use with your robot can be found at Hello Robot - Using Gamepads.
Programming Teleop - Blocks
This section makes the assumption that you have learned some of the FTC programming basics by going through the Hello Robot guide. If you have not gone through this guide please walk through it before proceeding.
In Hello Robot- Basics of Programming Drivetrains we covered how to program arcade drive with one joystick. For this example, we will be programming arcade drive using two joysticks. This type of drive is called "split arcade". In split arcade drive, the left joystick will control forward and reverse motion of the robot, and the right joystick will control turning. This is similar to how some RC cars are driven and video games are played.
Let's break down the Blocks Code for CENTERSTAGE!
Establishing Variables:
This year's Starter Bot makes use of a lot of variables.
| Variable | Purpose |
|---|---|
homearmposition | Tells the arm where it should sit when set to "home position" |
armIntakePosition | Tells the arm where it should sit to intake pixels |
armScorePosition | Tells the arm where it should be for scoring |
manualMode | Used for checks of if the arm is being manually controlled with the triggers or using the preset positions |
armShutdownThreshold | Used in the watchdog check for if the motors are running and when to shutdown |
wristUpPosition | Sets the value for when the wrist is in the up position |
wristDownPosition | Sets the value for when the wrist is in the down position |
gripperClosedPosition | Sets the default gripper position |
gripperOpenPosition | Sets the position for where the gripper should move to when the bumpers are pressed |
running | Used in the watchdog check for if the motors are in "run_to_position" mode |
You will need to program your servos with the SRS Programmer in your kit for accurate gripper and wrist movement!
Setting Up Encoders:
This code runs AFTER the initialization is activated, but BEFORE the play button is clicked.
This section allows the encoder on the arm Core Hex Motors to be reset to zero on start up and establishes their default behavior. Additionally, this sets two of the motors to run in reverse, one on the drivetrain and one of the arm motors.
This code will run ONCE after the play button is activated.
This section acts as an additional check for resetting the arm's power and position as well as setting the Core Hex Motors to "RUN_TO_POSITION" mode as default when the play button is clicked.
Split Arcade Drive:
The following sections all run REPEATEDLY in the "while loop" once the play button is activated.
Let's begin with programming our Split Arcade Drive. This code will take input from the right and left joysticks to determine the robot's movement. The left joystick controls forward and back, while the right stick controls left and right turning movement.
Manual Arm Movement:
The triggers on the controller determine the direction of the arm's rotation. The arm's power is determined by how far down both triggers are pressed. Additionally, the if/then statement switches the arm between manual drive and being ready to run the preset positions.
Arm and Wrist Preset Positions:
There are three preset positions for the arm and wrist on the Starter Bot- intake, home, and scoring.
| Controller Button | Position |
|---|---|
A/Cross | Arm moves to the down position, Wrist moves up |
B/Circle | Arm moves to the down position, Wrist moves down |
Y/Triangle | Arm moves up to behind the robot, Wrist moves to up - the arm should adjust to its final scoring position |
Re-zero Encoder:
When you re-zero the encoder the arm and wrist should be in the HOME position.
Watchdog to Shutdown Motor in Home Position:
This check prevents the Core Hex Motors from continuing to run while in home position to prevent potential overheating.
Let's take a closer look at all the parts of this if/then statement:
This if/then statement will only run if all the following are met:
The arm is not currently moving in manual mode from the triggers being pressed
The motors are actively on
The left Core Hex Motor's current and target position are less than or equal to the threshold (currently set to five)
Home position's value is set to 0 while Intake is set to 10
Gripper Controls:
When either or both of the bumpers on the controller are held down the gripper will open fully. When released it will return to the closed position to secure the fingers around the pixel.
Programming Teleop - OnBot Java
This section makes the assumption that you have learned some of the FTC programming basics by going through the Hello Robot guide. If you have not gone through this guide please walk through it before proceeding.
In Hello Robot- Basics of Programming Drivetrains we covered how to program arcade drive with one joystick. For this example, we will be programming arcade drive using two joysticks. This type of drive is called "split arcade". In split arcade drive, the left joystick will control forward and reverse motion of the robot, and the right joystick will control turning. This is similar to how some RC cars are driven and video games are played.
Full Robot Code
To use this code with your Starter Bot, copy and paste it into a new OnBot Java OP Mode!
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