Files
allwpilib/wpilibc/src/main/native/cpp/ADXRS450_Gyro.cpp
Thad House 9dc30797e4 Fix usage reporting indices (#2009)
According to NI, 0 is unspecified, and all the indices need to be
index + 1, so the first index becomes 1.
2019-10-29 21:34:10 -07:00

126 lines
3.8 KiB
C++

/*----------------------------------------------------------------------------*/
/* Copyright (c) 2015-2019 FIRST. 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 "frc/ADXRS450_Gyro.h"
#include <hal/HAL.h>
#include "frc/DriverStation.h"
#include "frc/Timer.h"
#include "frc/smartdashboard/SendableRegistry.h"
using namespace frc;
static constexpr auto kSamplePeriod = 0.0005_s;
static constexpr double kCalibrationSampleTime = 5.0;
static constexpr double kDegreePerSecondPerLSB = 0.0125;
// static constexpr int kRateRegister = 0x00;
// static constexpr int kTemRegister = 0x02;
// static constexpr int kLoCSTRegister = 0x04;
// static constexpr int kHiCSTRegister = 0x06;
// static constexpr int kQuadRegister = 0x08;
// static constexpr int kFaultRegister = 0x0A;
static constexpr int kPIDRegister = 0x0C;
// static constexpr int kSNHighRegister = 0x0E;
// static constexpr int kSNLowRegister = 0x10;
ADXRS450_Gyro::ADXRS450_Gyro() : ADXRS450_Gyro(SPI::kOnboardCS0) {}
ADXRS450_Gyro::ADXRS450_Gyro(SPI::Port port)
: m_spi(port), m_simDevice("ADXRS450_Gyro", port) {
if (m_simDevice) {
m_simAngle = m_simDevice.CreateDouble("Angle", false, 0.0);
m_simRate = m_simDevice.CreateDouble("Rate", false, 0.0);
}
m_spi.SetClockRate(3000000);
m_spi.SetMSBFirst();
m_spi.SetSampleDataOnLeadingEdge();
m_spi.SetClockActiveHigh();
m_spi.SetChipSelectActiveLow();
if (!m_simDevice) {
// Validate the part ID
if ((ReadRegister(kPIDRegister) & 0xff00) != 0x5200) {
DriverStation::ReportError("could not find ADXRS450 gyro");
return;
}
m_spi.InitAccumulator(kSamplePeriod, 0x20000000u, 4, 0x0c00000eu,
0x04000000u, 10u, 16u, true, true);
Calibrate();
}
HAL_Report(HALUsageReporting::kResourceType_ADXRS450, port + 1);
SendableRegistry::GetInstance().AddLW(this, "ADXRS450_Gyro", port);
}
static bool CalcParity(int v) {
bool parity = false;
while (v != 0) {
parity = !parity;
v = v & (v - 1);
}
return parity;
}
static inline int BytesToIntBE(uint8_t* buf) {
int result = static_cast<int>(buf[0]) << 24;
result |= static_cast<int>(buf[1]) << 16;
result |= static_cast<int>(buf[2]) << 8;
result |= static_cast<int>(buf[3]);
return result;
}
uint16_t ADXRS450_Gyro::ReadRegister(int reg) {
int cmd = 0x80000000 | static_cast<int>(reg) << 17;
if (!CalcParity(cmd)) cmd |= 1u;
// big endian
uint8_t buf[4] = {static_cast<uint8_t>((cmd >> 24) & 0xff),
static_cast<uint8_t>((cmd >> 16) & 0xff),
static_cast<uint8_t>((cmd >> 8) & 0xff),
static_cast<uint8_t>(cmd & 0xff)};
m_spi.Write(buf, 4);
m_spi.Read(false, buf, 4);
if ((buf[0] & 0xe0) == 0) return 0; // error, return 0
return static_cast<uint16_t>((BytesToIntBE(buf) >> 5) & 0xffff);
}
double ADXRS450_Gyro::GetAngle() const {
if (m_simAngle) return m_simAngle.Get();
return m_spi.GetAccumulatorIntegratedValue() * kDegreePerSecondPerLSB;
}
double ADXRS450_Gyro::GetRate() const {
if (m_simRate) return m_simRate.Get();
return static_cast<double>(m_spi.GetAccumulatorLastValue()) *
kDegreePerSecondPerLSB;
}
void ADXRS450_Gyro::Reset() {
if (m_simAngle) m_simAngle.Set(0.0);
if (m_simRate) m_simRate.Set(0.0);
m_spi.ResetAccumulator();
}
void ADXRS450_Gyro::Calibrate() {
Wait(0.1);
m_spi.SetAccumulatorIntegratedCenter(0);
m_spi.ResetAccumulator();
Wait(kCalibrationSampleTime);
m_spi.SetAccumulatorIntegratedCenter(m_spi.GetAccumulatorIntegratedAverage());
m_spi.ResetAccumulator();
}