edu.wpi.first.wpilibj
Class SPIDevice

java.lang.Object
  edu.wpi.first.wpilibj.SensorBase
      edu.wpi.first.wpilibj.SPIDevice

public class SPIDevice
extends SensorBase

Represents a device on an SPI bus Note that the cRIO only supports one SPI bus Attempting to open a second SPI device with a different shared pin (clk, mosi, miso) will result in an exception

Nested Class Summary

static class

SPIDevice.BadSPIConfigException

Field Summary

static boolean	BIT_ORDER_LSB_FIRST When transferring data the it is sent and received with the least significant bit first
static boolean	BIT_ORDER_MSB_FIRST When transferring data the it is sent and received with the most significant bit first
static boolean	CLOCK_POLARITY_ACTIVE_HIGH When transferring data the clock will be active high This corresponds to CPOL=0
static boolean	CLOCK_POLARITY_ACTIVE_LOW When transferring data the clock will be active low This corresponds to CPOL=1
static boolean	CS_ACTIVE_HIGH The CS will be brought high when the device is selected
static boolean	CS_ACTIVE_LOW The CS will be brought low when the device is selected
static boolean	DATA_ON_LEADING_EDGE Data is valid on the leading edge of the clock pulse This corresponds to CPHA=0
static boolean	DATA_ON_TRAILING_EDGE Data is valid on the trailing edge of the clock pulse This corresponds to CPHA=1
static char	FRAME_MODE_CHIP_SELECT The chip select line is active for the duration of the frame.
static char	FRAME_MODE_POST_LATCH The chip select line pulses after the transfer of each frame.
static char	FRAME_MODE_PRE_LATCH The chip select line pulses before the transfer of each frame.
static char	FRAME_MODE_PRE_POST_LATCH_PULSE The chip select line pulses before and after each frame.
double	MAX_CLOCK_FREQUENCY The maximum rate the clock can transmit at
double	MIN_CLOCK_FREQUENCY The minimum rate the clock can transmit at

Fields inherited from class edu.wpi.first.wpilibj.SensorBase

kAnalogChannels, kAnalogModules, kDigitalChannels, kPwmChannels, kRelayChannels, kSolenoidChannels, kSolenoidModules, kSystemClockTicksPerMicrosecond

Constructor Summary

SPIDevice(DigitalOutput cs)
Create a new device on the SPI bus.

SPIDevice(DigitalOutput cs, boolean csActiveHigh)
Create a new device on the SPI bus.

SPIDevice(DigitalOutput clk, DigitalOutput mosi, DigitalInput miso, DigitalOutput cs)
Create a new device on the SPI bus.

SPIDevice(DigitalOutput clk, DigitalOutput mosi, DigitalInput miso, DigitalOutput cs, boolean csActiveHigh)
Create a new device on the SPI bus.

SPIDevice(int slot, int csChannel)
Create a new device on the SPI bus.

SPIDevice(int slot, int csChannel, boolean csActiveHigh)
Create a new device on the SPI bus.

SPIDevice(int slot, int clkChannel, int mosiChannel, int misoChannel, int csChannel)
Create a new device on the SPI bus.

SPIDevice(int slot, int clkChannel, int mosiChannel, int misoChannel, int csChannel, boolean csActiveHigh)
Create a new device on the SPI bus.

Method Summary

void	free() Free the resources used by this object
void	setBitOrder(boolean bitOrder) Sets the bit order of the transfer sent and received values.
void	setClockPolarity(boolean clockPolarity) Sets the polarity of the clock when transferring data to the device
void	setClockRate(double hz) Set the frequence of the clock when sending data
void	setDataOnTrailing(boolean dataOnTrailing) If Data is valid at the beginning of the clock pulse or the end of the clock pulse
void	setFrameMode(char frameMode) Sets the Frame Mode which specifies the behavior of the chip select line in relation to the duration of the frame.
long[]	transfer(long[] writeValues, int[] numBits) Perform a SPI transfer where an array of bits are written and read.
long	transfer(long writeValue, int numBits) Perform a SPI transfer with the length of this device's current configuration.

Methods inherited from class edu.wpi.first.wpilibj.SensorBase

checkAnalogChannel, checkAnalogModule, checkDigitalChannel, checkDigitalModule, checkPWMChannel, checkPWMModule, checkRelayChannel, checkRelayModule, checkSolenoidChannel, checkSolenoidModule, getDefaultAnalogModule, getDefaultDigitalModule, getDefaultSolenoidModule, setDefaultAnalogModule, setDefaultDigitalModule, setDefaultSolenoidModule

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BIT_ORDER_MSB_FIRST

public static final boolean BIT_ORDER_MSB_FIRST

When transferring data the it is sent and received with the most significant bit first

See Also:

setBitOrder(boolean), Constant Field Values

BIT_ORDER_LSB_FIRST

public static final boolean BIT_ORDER_LSB_FIRST

When transferring data the it is sent and received with the least significant bit first

See Also:

setBitOrder(boolean), Constant Field Values

CLOCK_POLARITY_ACTIVE_HIGH

public static final boolean CLOCK_POLARITY_ACTIVE_HIGH

When transferring data the clock will be active high
This corresponds to CPOL=0

See Also:

setClockPolarity(boolean), Constant Field Values

CLOCK_POLARITY_ACTIVE_LOW

public static final boolean CLOCK_POLARITY_ACTIVE_LOW

When transferring data the clock will be active low
This corresponds to CPOL=1

See Also:

setClockPolarity(boolean), Constant Field Values

DATA_ON_LEADING_EDGE

public static final boolean DATA_ON_LEADING_EDGE

Data is valid on the leading edge of the clock pulse
This corresponds to CPHA=0

See Also:

#setDataOnFalling(boolean), Constant Field Values

DATA_ON_TRAILING_EDGE

public static final boolean DATA_ON_TRAILING_EDGE

Data is valid on the trailing edge of the clock pulse
This corresponds to CPHA=1

See Also:

#setDataOnFalling(boolean), Constant Field Values

CS_ACTIVE_HIGH

public static final boolean CS_ACTIVE_HIGH

The CS will be brought high when the device is selected

See Also:

Constant Field Values

CS_ACTIVE_LOW

public static final boolean CS_ACTIVE_LOW

The CS will be brought low when the device is selected

See Also:

Constant Field Values

FRAME_MODE_CHIP_SELECT

public static final char FRAME_MODE_CHIP_SELECT

The chip select line is active for the duration of the frame.

See Also:

setFrameMode(char), Constant Field Values

FRAME_MODE_PRE_LATCH

public static final char FRAME_MODE_PRE_LATCH

The chip select line pulses before the transfer of each frame.

See Also:

setFrameMode(char), Constant Field Values

FRAME_MODE_POST_LATCH

public static final char FRAME_MODE_POST_LATCH

The chip select line pulses after the transfer of each frame.

See Also:

setFrameMode(char), Constant Field Values

FRAME_MODE_PRE_POST_LATCH_PULSE

public static final char FRAME_MODE_PRE_POST_LATCH_PULSE

The chip select line pulses before and after each frame.

See Also:

setFrameMode(char), Constant Field Values

MAX_CLOCK_FREQUENCY

public final double MAX_CLOCK_FREQUENCY

The maximum rate the clock can transmit at

MIN_CLOCK_FREQUENCY

public final double MIN_CLOCK_FREQUENCY

The minimum rate the clock can transmit at

Constructor Detail

SPIDevice

public SPIDevice(int slot,
                 int clkChannel,
                 int mosiChannel,
                 int misoChannel,
                 int csChannel)

Create a new device on the SPI bus. The chip select line is active low

Parameters:

slot - The module of the digital IO for the device

clkChannel - The channel number for the clk channel

mosiChannel - The channel number for the mosi (output) channel

misoChannel - The channel number for the miso (input) channel

csChannel - The channel number for the chip select channel

SPIDevice

public SPIDevice(int slot,
                 int clkChannel,
                 int mosiChannel,
                 int misoChannel,
                 int csChannel,
                 boolean csActiveHigh)

Create a new device on the SPI bus.

Parameters:

slot - The module of the digital IO for the device

clkChannel - The channel number for the clk channel

mosiChannel - The channel number for the mosi (output) channel

misoChannel - The channel number for the miso (input) channel

csChannel - The channel number for the chip select channel

csActiveHigh - True if the chip select line should be high when the device is selected. False if it should be low.

SPIDevice

public SPIDevice(DigitalOutput clk,
                 DigitalOutput mosi,
                 DigitalInput miso,
                 DigitalOutput cs)

Create a new device on the SPI bus. The chip select line is active low

Parameters:

clk - The clock channel

mosi - The mosi (output) channel

miso - The miso (input) channel

cs - The chip select channel

SPIDevice

public SPIDevice(DigitalOutput clk,
                 DigitalOutput mosi,
                 DigitalInput miso,
                 DigitalOutput cs,
                 boolean csActiveHigh)

Create a new device on the SPI bus.

Parameters:

clk - The clock channel

mosi - The mosi (output) channel

miso - The miso (input) channel

cs - The chip select channel

csActiveHigh - True if the chip select line should be high when the device is selected. False if it should be low.

SPIDevice

public SPIDevice(int slot,
                 int csChannel)

Create a new device on the SPI bus. Must only be used after a device has been created establishing the clk, mosi and miso channels. The chip select line is active low

Parameters:

slot - The module of the digital output for the device's chip select pin

csChannel - The channel for the digital output for the device's chip select pin

SPIDevice

public SPIDevice(int slot,
                 int csChannel,
                 boolean csActiveHigh)

Create a new device on the SPI bus. Must only be used after a device has been created establishing the clk, mosi and miso channels.

Parameters:

slot - The module of the digital output for the device's chip select pin

csChannel - The channel for the digital output for the device's chip select pin

csActiveHigh - True if the chip select line should be high when the device is selected. False if it should be low.

SPIDevice

public SPIDevice(DigitalOutput cs)

Create a new device on the SPI bus. Must only be used after a device has been created establishing the clk, mosi and miso channels. The chip select line is active low

Parameters:

cs - The chip select channel

SPIDevice

public SPIDevice(DigitalOutput cs,
                 boolean csActiveHigh)

Create a new device on the SPI bus. Must only be used after a device has been created establishing the clk, mosi and miso channels.

Parameters:

cs - The chip select channel

csActiveHigh - True if the chip select line should be high when the device is selected. False if it should be low.

Method Detail

free

public void free()

Free the resources used by this object

Overrides:

free in class SensorBase

transfer

public long transfer(long writeValue,
                     int numBits)

Perform a SPI transfer with the length of this device's current configuration. This will select the device, transfer the data and then deselect the device

Parameters:

writeValue - The value to write to the device

numBits - The number of bits to write/read

transfer

public long[] transfer(long[] writeValues,
                       int[] numBits)

Perform a SPI transfer where an array of bits are written and read. The number of bits to write and read is specified in numBits
The whole transfer will occur with the cs line held active throughout

Parameters:

writeValues - The value to write to the device

numBits - The number of bits to write/read

setBitOrder

public final void setBitOrder(boolean bitOrder)

Sets the bit order of the transfer sent and received values. The value transfered/received will always be the lowest bits of the value. This method just sets the order in which those bits are transfered.

Parameters:

bitOrder - true=Most significant bit first, false=Least significant bit first

See Also:

BIT_ORDER_MSB_FIRST, BIT_ORDER_LSB_FIRST

setClockPolarity

public final void setClockPolarity(boolean clockPolarity)

Sets the polarity of the clock when transferring data to the device

Parameters:

clockPolarity - true=Clock active low, false=Clock active high

See Also:

CLOCK_POLARITY_ACTIVE_HIGH, CLOCK_POLARITY_ACTIVE_LOW

setDataOnTrailing

public final void setDataOnTrailing(boolean dataOnTrailing)

If Data is valid at the beginning of the clock pulse or the end of the clock pulse

Parameters:

dataOnTrailing - true=Process data on the trailing edge of the clock, false=Process data on leading edge of the clock

See Also:

DATA_ON_LEADING_EDGE, DATA_ON_TRAILING_EDGE

setFrameMode

public final void setFrameMode(char frameMode)

Sets the Frame Mode which specifies the behavior of the chip select line in relation to the duration of the frame.

Parameters:

frameMode - 0 = low for duration of frame, 1 = pulse before transfer, 2 = pulse after transfer, 3 = pulse before and after transfer

See Also:

FRAME_MODE_CHIP_SELECT, FRAME_MODE_PRE_LATCH, FRAME_MODE_POST_LATCH, FRAME_MODE_PRE_POST_LATCH_PULSE

setClockRate

public final void setClockRate(double hz)

Set the frequence of the clock when sending data

Parameters:

hz - The frequency of the clock in hz

See Also:

MIN_CLOCK_FREQUENCY, MAX_CLOCK_FREQUENCY