FTC Moving 202008

Encoder Notes

Documentation and tutorials

• Lesson: Exercise: Using Encoders on PDX STEM
• [https://docs.revrobotics.com/docs/first-tech-challenge FIRST Tech Challenge - REV Documentation}
• Motor PIDF Tuning Guide
• Motor Encoder Guide
• Control Hub and Expansion Hub Firmware Update Guide

issues with pidf

• PIDF for goBilda 5202 very slow #150
• Tuning PIDF - slow movement for small errors

Issue reported and solved

• [https://github.com/ftctechnh/ftc_app/issues/287 DC motor running too slow in RUN_USING_ENCODER run mode #287}
• Robot getting stuck with RUN_TO_POSITION
• DcMotor - Run to position not working
• Drive Straight
• Not going straight
• Straight line driving
• App Update 5.3-64b: PID vs PIDF

Firmware https://www.revrobotics.com/software/#exphubpreviousfirmware

api

• DcMotor
• DcMotor RunMode

PID

• isPIDMode
• https://stemrobotics.cs.pdx.edu/node/7268
• https://github.com/ftctechnh/ftc_app/wiki/Changing-PID-Coefficients Changing PID Coefficients]
• https://github.com/ftctechnh/ftc_app/wiki

pid api

PIDCoefficients DcMotorEx

• DcMotorEx

Code snipets

 DcMotorEx motorExLeft;
 motorExLeft = (DcMotorEx)hardwareMap.get(DcMotor.class, "left_drive”);
 PIDCoefficients pidOrig = motorExLeft.getPIDCoefficients(DcMotor.RunMode.RUN_USING_ENCODER);
 pidOrig.
 PIDCoefficients pidNew = new PIDCoefficients(NEW_P, NEW_I, NEW_D);
 motorExLeft.setPIDCoefficients(DcMotor.RunMode.RUN_USING_ENCODER, pidNew);

• getVelocity in ticks per second
• f is the tolerance