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  • Introduction
  • Getting Started with Control Hub
    • Connect to the Robot Controller Console
    • Updating Wi-Fi Settings
    • Connecting Driver Station to Control Hub
    • Wiring Diagram
    • Next Steps
  • Getting Started with Driver Hub
  • Adding More Motors
    • SPARKmini Motor Controller
    • Adding an Expansion Hub
  • Troubleshooting the Control System
    • General Troubleshooting
    • Control Hub Troubleshooting
    • Driver Hub Troubleshooting
      • Driver Hub Battery Troubleshooting
    • Expansion Hub Troubleshooting
    • Status LED Blink Codes
  • System Overview
    • Control Hub Specifications
    • Expansion Hub Specifications
    • Driver Hub Specifications
    • Port Pinouts
    • Protection Features
    • Cables and Connectors
      • XT-30 - Power Cable
      • JST VH - Motor Power
      • JST PH - Sensors and RS485
    • Integrated Sensors
    • Dimensions and Important Component Locations
  • Updating and Managing
    • Managing Wi-Fi on the Control Hub
    • REV Hardware Client
    • Updating Firmware
      • Firmware Changelog
    • Updating Operating System
      • Control Hub Operating System Changelog
    • Updating Robot Controller Application
      • Updating Robot Controller Application via Android Studio
    • Updating the Driver Hub
      • Driver Hub OS - Change Log
    • Accessing Log Files
    • Android Studio - Deploying Code Wirelessly
  • Hello Robot - Intro to Blocks Programming
    • Welcome to Hello Robot!
    • Where to Program - Client vs. Browser
      • What is an OpMode?
    • Setting up a Configuration
      • Common Errors in Configuration
    • Using a Gamepad
    • Part 1: Tackling the Basics
      • Tackling the Basics Directory - Blocks
      • Creating an OpMode - Blocks
      • Programming Essentials
      • Programming Servos
        • Programming Servo Basics
        • Using a Gamepad with a Servo
        • Programming Servo Telemetry
      • Programming Motors
        • Programming Motors Basics
        • Programming a Motor with a Gamepad
        • Programming Motor Telemetry
      • Programming Touch Sensors
      • Programming Color Sensors
        • Color Sensor Telemetry
        • Detecting Color
    • Part 2: Robot Control
      • Robot Control Blocks Directory
      • Programming Drivetrain Motors
      • Arcade Style TeleOp - Blocks
        • Establishing Variables in Blocks
        • Motor Power vs. Robot Movement
        • Programming Arcade Drive
      • Arm Control - Blocks
        • Adding a Limit Switch
      • Robot Control Full Program
    • Part 3: Autonomous and Encoders
      • ElapsedTime - Blocks
        • ElapsedTime Setup
        • ElapsedTime Logic
        • ElapsedTime - Multiple Movements
      • Encoder Basics
      • Drivetrain Encoders - Blocks
        • Converting Encoder Ticks to a Distance
        • Moving to a Target Distance
        • Setting Velocity
        • Turning the Drivetrain Using RUN_TO_POSITION
      • Arm Control with Encoders - Blocks
        • Estimating the Position of the Arm
        • Calculating Target Position
        • Using Limits to Control Range of Motion
    • Part 4: Going Beyond!
      • Exploring Functions
      • Programming Mecanum - Simplified
      • Programming Mecanum - Refined
  • Hello Robot - Intro to OnBot Java Programming
    • Welcome to Hello Robot!
    • Where to Program - Client vs. Browser
      • What is an OpMode?
    • Setting up a Configuration
      • Common Errors in Configuration
    • Using a Gamepad
    • Part 1: Tackling the Basics
      • Tackling the Basics Directory - OnBot
      • Creating an OpMode - OnBot
      • Programming Essentials
      • Programming Servos
        • Programming Servo Basics
        • Using a Gamepad with a Servo
        • Programming Servo Telemetry
      • Programming Motors
        • Programming Motor Basics
        • Programming a Motor with a Gamepad
        • Programming Motor Telemetry
      • Programming Touch Sensors
    • Part 2: Robot Control
      • Robot Control OnBot Java Directory
      • Programming Drivetrain Motors
      • Arcade Style TeleOp - OnBot Java
        • Establishing Variables in OnBot Java
        • Motor Power vs. Robot Movement
        • Programming Arcade Drive
      • Arm Control - OnBot Java
        • Adding a Limit Switch
      • Robot Control Full Program
    • Part 3: Autonomous and Encoders
      • ElapsedTime - OnBot Java
        • ElapsedTime Setup
        • ElapsedTime Logic
        • ElapsedTime - Multiple Movements
      • Encoder Basics
      • Drivetrain Encoders - OnBot Java
        • Converting Encoder Ticks to a Distance
        • Moving to a Target Distance
        • Setting Velocity
        • Turning the Drivetrain Using RUN_TO_POSITION
      • Arm Control with Encoders - OnBot Java
        • Estimating the Position of the Arm
        • Calculating Target Position
        • Using Limits to Control Range of Motion
  • Sensors
    • Introduction to Sensors
    • Digital
    • Analog
    • I2C
      • IMU
        • Orientating the IMU
      • Adding an External IMU to your Hub
    • Encoders
      • REV Motor Encoders
      • Through Bore Encoder
    • Using 3rd Party Sensors
      • Sensor Compatibility Chart
  • Useful Links
    • REV DUO Build System
  • Legacy Documentation
    • Configuring Your Android Devices
    • Expansion Hub with Android Device Robot Controller
      • Driver Station and Robot Controller Pairing
      • Wiring Diagram
      • Configuration
    • REV Hub Interface Software
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On this page
  • Setting up the Drivetrain Encoders
  • RUN_TO_POSITION
  • Quick Check!
  • STOP_AND_RESET_ENCODERS
  • Setting up the whileLoop

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  1. Hello Robot - Intro to Blocks Programming
  2. Part 3: Autonomous and Encoders

Drivetrain Encoders - Blocks

PreviousEncoder BasicsNextConverting Encoder Ticks to a Distance

Last updated 6 months ago

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Moving the motors to a specific position, using the encoders, removes any potential inaccuracies or inconsistencies from using Elapsed Time. The focus of this section is to move the robot to a target position using encoders.

Setting up the Drivetrain Encoders

For this tutorial, our OpMode is named HelloRobot_Encoder!

Before diving in too far, recall that for certain , like the , one of the motors needs to be reversed as the motors are mirrored. In our example, we are adding the block under the .

RUN_TO_POSITION

If we want our robot to travel a specific distance we will need to do a bit of math beforehand to calculate the TargetPosition. But for now let's start simple by setting the target position to 1000 ticks.

Order matters! The TargetPosition block must come before RUN_TO_POSITION mode is set or it will result in an error.

As mentioned, normally there would be more math involved to help determine how fast the motors should move to reach the desired position. But for testing purposes, we are going to start by keeping it simple!

Quick Check!

Save your OpMode and give it a test. What happens once you press play? What happens if you stop the program then start it again?

What happens when testing?

Likely your motors turned on when testing out the code to spin until they've reached the set position.

Some may have turned off once the position was reached, but you may also experience the motors twitching or making small adjustments in an attempt to reach the position. Then when starting the code again, the motor either continued twitching or did not move at all.

Recall we may need to reset our encoder to zero before running a program! The motor will continuously try to adjust until it hits the set position, but if it's already there it won't move!

Adjusting the power may help prevent the motor from overshooting the position and needing to repeatedly adjust.

STOP_AND_RESET_ENCODERS

For our demo code we will want to request our motors reset their encoders during the initialization process of the program.

Setting up the whileLoop

Let's say we want our program to run only for however long it takes for the motors to reach designated position. Or maybe we intend for the robot to do something else after reaching the destination. For this we will need to edit our whileLoop block!

Even though we are ending a new exit case for our loop, we must always have our call to check opModeIsActive or our program will instantly timeout!

Save your OpMode and give it a try!

As soon as the motors hit the desired position the program will end instead of continuously run in the event they do not perfectly hit the position.

As introduced in , using RUN_TO_POSITION mode requires a three step process.

The first step is setting target position. To do so, grab the block and add it to under the comment. For this example, we are setting our position after pressing Initialize, but before we hit Play on the Driver Hub.

The next step is to set both motors to the RUN_TO_POSITION mode. Place the block beneath the block.

Add the block beneath the block. Let's go ahead and change the duty cycle (or power) of both motors to 0.8, instead of 1.

Grab an block from the logic menu and add it to the while loop. On the left side of the block add the block. On the right side add the block.

Embed the in another block. Place the on the right side of the block. Our call for the OpMode will go in the lefthand side slot.

Right now the while loop is waiting for the right and left motors to reach their respective targets. There may be occasions when you want to wait for both motors to reach their target position, in this case the can be used such as:

drivetrains
Class Bot V2
Adding TargetPosition for the drivetrain motors
Changing the motors to RUN_TO_POSITION
Setting the power for the motors
Adding a block to STOP_AND_RESET_ENCODER
In this section we will edit our whileLoop
The call motor block is under the DcMotor menu
Full logic statement for the whileLoop
Setting the rightmotor to run in reverse
Using Encoders