# validated: 2016-12-31 JW 8f67f2c24cb9 athena/java/edu/wpi/first/wpilibj/ADXL362.java
#----------------------------------------------------------------------------
# Copyright (c) FIRST 2008-2012. 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.
#----------------------------------------------------------------------------
import hal
from .driverstation import DriverStation
from .interfaces import Accelerometer
from .spi import SPI
from .sensorbase import SensorBase
from .livewindow import LiveWindow
__all__ = ["ADXL362"]
[docs]class ADXL362(SensorBase):
"""
ADXL362 SPI Accelerometer.
This class allows access to an Analog Devices ADXL362 3-axis accelerometer.
.. not_implemented: init
"""
kRegWrite = 0x0A
kRegRead = 0x0B
kPartIdRegister = 0x02
kDataRegister = 0x0E
kFilterCtlRegister = 0x2C
kPowerCtlRegister = 0x2D
kFilterCtl_Range2G = 0x00
kFilterCtl_Range4G = 0x40
kFilterCtl_Range8G = 0x80
kFilterCtl_ODR_100Hz = 0x03
kPowerCtl_UltraLowNoise = 0x20
kPowerCtl_AutoSleep = 0x04
kPowerCtl_Measure = 0x02
Range = Accelerometer.Range
[docs] class Axes:
kX = 0x00
kY = 0x02
kZ = 0x04
def __init__(self, range, port=None):
"""Constructor.
:param range: The range (+ or -) that the accelerometer will measure.
:type range: :class:`.ADXL362.Range`
:param port: The SPI port that the accelerometer is connected to
:type port: :class:`.SPI.Port`
"""
if port is None:
port = SPI.Port.kOnboardCS1
self.spi = SPI(port)
self.spi.setClockRate(3000000)
self.spi.setMSBFirst()
self.spi.setSampleDataOnFalling()
self.spi.setClockActiveLow()
self.spi.setChipSelectActiveLow()
# Validate the part ID
data = [self.kRegRead, self.kPartIdRegister, 0]
data = self.spi.transaction(data)
if data[2] != 0xF2:
DriverStation.reportError("could not find ADXL362 on SPI port " + port, False)
self.spi.free()
self.spi = None
return
self.setRange(range)
# Turn on the measurements
self.spi.write([self.kRegWrite, self.kPowerCtlRegister,
self.kPowerCtl_Measure | self.kPowerCtl_UltraLowNoise])
hal.report(hal.UsageReporting.kResourceType_ADXL362,
port)
LiveWindow.addSensor("ADXL362", port, self)
[docs] def free(self):
LiveWindow.removeComponent(self)
if self.spi:
self.spi.free()
super().free()
# Accelerometer interface
[docs] def setRange(self, range):
"""Set the measuring range of the accelerometer.
:param range: The maximum acceleration, positive or negative, that
the accelerometer will measure.
:type range: :class:`ADXL362.Range`
"""
if range == self.Range.k2G:
value = self.kFilterCtl_Range2G
self.gsPerLSB = 0.001
elif range == self.Range.k4G:
value = self.kFilterCtl_Range4G
self.gsPerLSB = 0.002
# 16G not supported; treat as 8G
elif range == self.Range.k8G or \
range == self.Range.k16G:
value = self.kFilterCtl_Range8G
self.gsPerLSB = 0x004
else:
raise ValueError("Invalid range argument '%s'" % range)
self.spi.write([self.kRegWrite, self.kFilterCtlRegister,
self.kFilterCtl_ODR_100Hz | value])
[docs] def getX(self):
"""Get the x axis acceleration
:returns: The acceleration along the x axis in g-forces
"""
return self.getAcceleration(self.Axes.kX)
[docs] def getY(self):
"""Get the y axis acceleration
:returns: The acceleration along the y axis in g-forces
"""
return self.getAcceleration(self.Axes.kY)
[docs] def getZ(self):
"""Get the z axis acceleration
:returns: The acceleration along the z axis in g-forces
"""
return self.getAcceleration(self.Axes.kZ)
[docs] def getAcceleration(self, axis):
"""Get the acceleration of one axis in Gs.
:param axis: The axis to read from.
:returns: An object containing the acceleration measured on each axis in Gs.
"""
if self.spi is None:
return 0.0
data = [self.kRegRead,
self.kDataRegister + axis, 0, 0]
data = self.spi.transaction(data)
# Sensor is little endian... swap bytes
rawAccel = (data[2] << 8) | data[1]
return rawAccel * self.gsPerLSB
[docs] def getAccelerations(self):
"""Get the acceleration of all axes in Gs.
:returns: X,Y,Z tuple of acceleration measured on all axes in Gs.
"""
if self.spi is None:
return 0.0, 0.0, 0.0
# Select the data address.
data = [0] * 8
data[0] = self.kRegRead
data[1] = self.kDataRegister
data = self.spi.transaction(data)
# Sensor is little endian... swap bytes
rawData = []
for i in range(3):
rawData.append((data[i*2+2] << 8) | data[i*2+1])
return (rawData[0] * self.gsPerLSB,
rawData[1] * self.gsPerLSB,
rawData[2] * self.gsPerLSB)
# Live Window code, only does anything if live window is activated.
def getSmartDashboardType(self):
return "3AxisAccelerometer"
def updateTable(self):
if self.table is not None:
self.table.putNumber("X", self.getX())
self.table.putNumber("Y", self.getY())
self.table.putNumber("Z", self.getZ())