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55 lines
2.5 KiB
Python
55 lines
2.5 KiB
Python
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#!/usr/bin/env python3
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#
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# Copyright (c) FIRST and other WPILib contributors.
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# Open Source Software; you can modify and/or share it under the terms of
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# the WPILib BSD license file in the root directory of this project.
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#
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import wpilib
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import math
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class MyRobot(wpilib.TimedRobot):
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"""
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Sample program displaying the value of a quadrature encoder on the SmartDashboard. Quadrature
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Encoders are digital sensors which can detect the amount the encoder has rotated since starting
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as well as the direction in which the encoder shaft is rotating. However, encoders can not tell
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you the absolute position of the encoder shaft (ie, it considers where it starts to be the zero
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position, no matter where it starts), and so can only tell you how much the encoder has rotated
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since starting. Depending on the precision of an encoder, it will have fewer or greater ticks per
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revolution; the number of ticks per revolution will affect the conversion between ticks and
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distance, as specified by DistancePerPulse. One of the most common uses of encoders is in the
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drivetrain, so that the distance that the robot drives can be precisely controlled during the
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autonomous mode.
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"""
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def __init__(self):
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"""Robot initialization function"""
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super().__init__()
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self.encoder = wpilib.Encoder(1, 2, False, wpilib.Encoder.EncodingType.k4X)
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# Defines the number of samples to average when determining the rate.
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# On a quadrature encoder, values range from 1-255;
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# larger values result in smoother but potentially
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# less accurate rates than lower values.
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self.encoder.setSamplesToAverage(5)
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# Defines how far the mechanism attached to the encoder moves per pulse. In
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# this case, we assume that a 360 count encoder is directly
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# attached to a 3 inch diameter (1.5inch radius) wheel,
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# and that we want to measure distance in inches.
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self.encoder.setDistancePerPulse(1.0 / 360.0 * 2.0 * math.pi * 1.5)
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# Defines the lowest rate at which the encoder will
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# not be considered stopped, for the purposes of
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# the GetStopped() method. Units are in distance / second,
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# where distance refers to the units of distance
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# that you are using, in this case inches.
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self.encoder.setMinRate(1.0)
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def teleopPeriodic(self):
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wpilib.SmartDashboard.putNumber("Encoder Distance", self.encoder.getDistance())
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wpilib.SmartDashboard.putNumber("Encoder Rate", self.encoder.getRate())
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