forward strafe turn speed denominator runOpMode BASIC MECANUM TELEOP Left stick: drive forward/backward and strafe left/right. Right stick X: rotate. Hold the left bumper: slow mode. The loop repeats until STOP is pressed. {"commentPositionLeft":-115,"commentPositionTop":-125} MOTOR SETUP — WHY DIRECTIONS MATTER The motors on opposite sides are mounted as mirror images. If all four received +1 without correction, one side would spin backward. Reversing the left motors in software makes +1 mean forward for every wheel. BRAKE means the motor actively holds still at zero power instead of coasting. front_left_driveAsDcMotor Direction {"IDENTIFIER":"front_left_drive"} REVERSE back_left_driveAsDcMotor Direction {"IDENTIFIER":"back_left_drive"} REVERSE front_right_driveAsDcMotor Direction {"IDENTIFIER":"front_right_drive"} FORWARD back_right_driveAsDcMotor Direction {"IDENTIFIER":"back_right_drive"} REVERSE front_left_driveAsDcMotor ZeroPowerBehavior {"IDENTIFIER":"front_left_drive"} BRAKE front_right_driveAsDcMotor ZeroPowerBehavior {"IDENTIFIER":"front_right_drive"} BRAKE back_left_driveAsDcMotor ZeroPowerBehavior {"IDENTIFIER":"back_left_drive"} BRAKE back_right_driveAsDcMotor ZeroPowerBehavior {"IDENTIFIER":"back_right_drive"} BRAKE front_left_driveAsDcMotor Mode {"IDENTIFIER":"front_left_drive"} RUN_WITHOUT_ENCODER front_right_driveAsDcMotor Mode {"IDENTIFIER":"front_right_drive"} RUN_WITHOUT_ENCODER back_left_driveAsDcMotor Mode {"IDENTIFIER":"back_left_drive"} RUN_WITHOUT_ENCODER back_right_driveAsDcMotor Mode {"IDENTIFIER":"back_right_drive"} RUN_WITHOUT_ENCODER front_left_driveAsDcMotor Power {"IDENTIFIER":"front_left_drive"} 0 front_right_driveAsDcMotor Power {"IDENTIFIER":"front_right_drive"} 0 back_left_driveAsDcMotor Power {"IDENTIFIER":"back_left_drive"} 0 back_right_driveAsDcMotor Power {"IDENTIFIER":"back_right_drive"} 0 READY - basic mecanum drive INIT AND START INIT means initialize: prepare the robot without allowing it to drive. waitForStart pauses here until the human presses START on the Driver Station. This safety boundary prevents joystick noise or unfinished setup from moving the robot early. WHILE JOYSTICK COORDINATES Each joystick axis reports a decimal from -1 to +1. Left-stick X means side-to-side, and left-stick Y means up/down. Controllers report pushing upward as a negative Y number, so the program multiplies it by -1 to make pushing forward produce positive forward motion. Right-stick X becomes rotation. forward NEG gamepad1 LeftStickY {"IDENTIFIER":"gamepad1"} strafe gamepad1 LeftStickX {"IDENTIFIER":"gamepad1"} turn gamepad1 RightStickX {"IDENTIFIER":"gamepad1"} speed 1 SLOW MODE Normally speed is 1.0, meaning 100% of the calculated power. Holding the left bumper changes the scale to 0.35, or 35%. Multiplying every wheel by the same scale keeps the movement direction the same while making practice safer and more precise. gamepad1 LeftBumper {"IDENTIFIER":"gamepad1"} speed 0.35 WHY ADD ABSOLUTE VALUES? Absolute value removes the plus or minus sign, because we only need the size of each request. Adding |forward| + |strafe| + |turn| estimates the largest combined demand. A diagonal joystick command can otherwise ask a wheel for more than 1.0 power. denominator ADD ADD ABS forward ABS strafe ABS turn NORMALIZATION — SHRINK WITHOUT CHANGING SHAPE Motor power must stay between -1 and +1. If the denominator is less than 1, we replace it with 1 so we never make small commands larger. Dividing all wheels by the same denominator shrinks oversized values equally, preserving the intended direction and rotation. LT denominator 1 denominator 1 MECANUM WHEEL MIXING Mecanum rollers let the robot combine three motions: forward, sideways, and turning. Each wheel needs a different plus/minus combination. For example, adding sideways power to one diagonal and subtracting it from the other diagonal creates a strafe without rotating the robot. front_left_driveAsDcMotor Power {"IDENTIFIER":"front_left_drive"} MULTIPLY speed DIVIDE ADD ADD forward strafe turn denominator front_right_driveAsDcMotor Power {"IDENTIFIER":"front_right_drive"} MULTIPLY speed DIVIDE MINUS MINUS forward strafe turn denominator back_left_driveAsDcMotor Power {"IDENTIFIER":"back_left_drive"} MULTIPLY speed DIVIDE ADD MINUS forward strafe turn denominator back_right_driveAsDcMotor Power {"IDENTIFIER":"back_right_drive"} MULTIPLY speed DIVIDE MINUS ADD forward strafe turn denominator TELEMETRY MEANS DATA SENT BACK Telemetry is information the Robot Controller sends to the Driver Station screen. It does not control the robot. These rows help us debug by showing the joystick requests and the power actually sent to each motor. Forward command forward Strafe command strafe Rotate command turn Speed scale speed FL motor power front_left_driveAsDcMotor Power {"IDENTIFIER":"front_left_drive"} FR motor power front_right_driveAsDcMotor Power {"IDENTIFIER":"front_right_drive"} BL motor power back_left_driveAsDcMotor Power {"IDENTIFIER":"back_left_drive"} BR motor power back_right_driveAsDcMotor Power {"IDENTIFIER":"back_right_drive"} Face buttons A: gamepad1 A {"IDENTIFIER":"gamepad1"} B: gamepad1 B {"IDENTIFIER":"gamepad1"} X: gamepad1 X {"IDENTIFIER":"gamepad1"} Y: gamepad1 Y {"IDENTIFIER":"gamepad1"} D-pad U: gamepad1 DpadUp {"IDENTIFIER":"gamepad1"} D: gamepad1 DpadDown {"IDENTIFIER":"gamepad1"} L: gamepad1 DpadLeft {"IDENTIFIER":"gamepad1"} R: gamepad1 DpadRight {"IDENTIFIER":"gamepad1"} Other buttons LB: gamepad1 LeftBumper {"IDENTIFIER":"gamepad1"} RB: gamepad1 RightBumper {"IDENTIFIER":"gamepad1"} Start: gamepad1 Start {"IDENTIFIER":"gamepad1"} Back: gamepad1 Back {"IDENTIFIER":"gamepad1"} FINAL SAFETY STOP The loop ends when STOP is pressed or communication ends. Explicitly writing zero to all four motors is a final safety step so no earlier power value can remain active. front_left_driveAsDcMotor Power {"IDENTIFIER":"front_left_drive"} 0 front_right_driveAsDcMotor Power {"IDENTIFIER":"front_right_drive"} 0 back_left_driveAsDcMotor Power {"IDENTIFIER":"back_left_drive"} 0 back_right_driveAsDcMotor Power {"IDENTIFIER":"back_right_drive"} 0