allwpilib/wpilibc/wpilibC++IntegrationTests/src/FakeEncoderTest.cpp

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2014. All Rights Reserved.                             */
/* Open Source Software - may be modified and shared by FRC teams. The code	  */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project.                                                               */
/*----------------------------------------------------------------------------*/

#include "WPILib.h"
#include "gtest/gtest.h"
#include "TestBench.h"

static const double kDelayTime = 0.001;

class FakeEncoderTest : public testing::Test {
protected:
	DigitalOutput *m_outputA;
	DigitalOutput *m_outputB;
	AnalogOutput *m_indexOutput;

	Encoder *m_encoder;
	AnalogTrigger *m_indexAnalogTrigger;
	AnalogTriggerOutput *m_indexAnalogTriggerOutput;

	virtual void SetUp() override {
		m_outputA = new DigitalOutput(TestBench::kLoop2OutputChannel);
		m_outputB = new DigitalOutput(TestBench::kLoop1OutputChannel);
		m_indexOutput = new AnalogOutput(TestBench::kAnalogOutputChannel);
                m_outputA->Set(false);
                m_outputB->Set(false);
		m_encoder = new Encoder(TestBench::kLoop1InputChannel, TestBench::kLoop2InputChannel);
		m_indexAnalogTrigger = new AnalogTrigger(TestBench::kFakeAnalogOutputChannel);
		m_indexAnalogTrigger->SetLimitsVoltage(2.0, 3.0);
		m_indexAnalogTriggerOutput = m_indexAnalogTrigger->CreateOutput(AnalogTriggerType::kState);
	}

	virtual void TearDown() override {
		delete m_outputA;
		delete m_outputB;
		delete m_indexOutput;
		delete m_encoder;
		delete m_indexAnalogTrigger;
		delete m_indexAnalogTriggerOutput;
	}

	/**
	 * Output pulses to the encoder's input channels to simulate a change of 100 ticks
	 */
	void Simulate100QuadratureTicks() {
		for(int i = 0; i < 100; i++) {
			m_outputA->Set(true);
			Wait(kDelayTime);
			m_outputB->Set(true);
			Wait(kDelayTime);
			m_outputA->Set(false);
			Wait(kDelayTime);
			m_outputB->Set(false);
			Wait(kDelayTime);
		}
	}

	void SetIndexHigh() {
		m_indexOutput->SetVoltage(5.0);
		Wait(kDelayTime);
	}

	void SetIndexLow() {
		m_indexOutput->SetVoltage(0.0);
		Wait(kDelayTime);
	}
};

/**
 * Test the encoder by reseting it to 0 and reading the value.
 */
TEST_F(FakeEncoderTest, TestDefaultState) {
	EXPECT_FLOAT_EQ(0.0f, m_encoder->Get())
		<< "The encoder did not start at 0.";
}

/**
 * Test the encoder by setting the digital outputs and reading the value.
 */
TEST_F(FakeEncoderTest, TestCountUp) {
    m_encoder->Reset();
	Simulate100QuadratureTicks();

	EXPECT_FLOAT_EQ(100.0f, m_encoder->Get())
		<< "Encoder did not count to 100.";
}

/**
 * Test that the encoder can stay reset while the index source is high
 */
TEST_F(FakeEncoderTest, TestResetWhileHigh) {
	m_encoder->SetIndexSource(m_indexAnalogTriggerOutput, Encoder::IndexingType::kResetWhileHigh);

	SetIndexLow();
	Simulate100QuadratureTicks();
	SetIndexHigh();
	EXPECT_EQ(0, m_encoder->Get());

	Simulate100QuadratureTicks();
	EXPECT_EQ(0, m_encoder->Get());
}

/**
 * Test that the encoder can reset when the index source goes from low to high
 */
TEST_F(FakeEncoderTest, TestResetOnRisingEdge) {
	m_encoder->SetIndexSource(m_indexAnalogTriggerOutput, Encoder::IndexingType::kResetOnRisingEdge);

	SetIndexLow();
	Simulate100QuadratureTicks();
	SetIndexHigh();
	EXPECT_EQ(0, m_encoder->Get());

	Simulate100QuadratureTicks();
	EXPECT_EQ(100, m_encoder->Get());
}

/**
 * Test that the encoder can stay reset while the index source is low
 */
TEST_F(FakeEncoderTest, TestResetWhileLow) {
	m_encoder->SetIndexSource(m_indexAnalogTriggerOutput, Encoder::IndexingType::kResetWhileLow);

	SetIndexHigh();
	Simulate100QuadratureTicks();
	SetIndexLow();
	EXPECT_EQ(0, m_encoder->Get());

	Simulate100QuadratureTicks();
	EXPECT_EQ(0, m_encoder->Get());
}

/**
 * Test that the encoder can reset when the index source goes from high to low
 */
TEST_F(FakeEncoderTest, TestResetOnFallingEdge) {
	m_encoder->SetIndexSource(m_indexAnalogTriggerOutput, Encoder::IndexingType::kResetOnFallingEdge);

	SetIndexHigh();
	Simulate100QuadratureTicks();
	SetIndexLow();
	EXPECT_EQ(0, m_encoder->Get());

	Simulate100QuadratureTicks();
	EXPECT_EQ(100, m_encoder->Get());
}