Class Pcx857x

Represents a Pcx857x I2C IO Expander

Assembly: Pcx857x.dll

View Source

Declaration

public abstract class Pcx857x : IDigitalOutputController, IDigitalInputController, IDigitalInterruptController, IPinController, II2cPeripheral, IDisposable

Derived:
Meadow.Foundation.ICs.IOExpanders.Pcx8574

Implements:
Meadow.Hardware.IDigitalOutputController, Meadow.Hardware.IDigitalInputController, Meadow.Hardware.IDigitalInterruptController, Meadow.Hardware.IPinController, Meadow.Hardware.II2cPeripheral, System.IDisposable

Properties

NumberOfPins

The number of IO pins available on the device

View Source

Declaration

public abstract int NumberOfPins { get; }

DefaultI2cAddress

The default I2C address for the peripheral

View Source

Declaration

public byte DefaultI2cAddress { get; }

IsDisposed

Is the object disposed

View Source

Declaration

public bool IsDisposed { get; }

Fields

createdPorts

Did we create the port(s) used by the peripheral

View Source

Declaration

protected bool createdPorts

i2cComms

The I2C Communications object

View Source

Declaration

protected readonly II2cCommunications i2cComms

Methods

GetAddressFromPins(bool, bool, bool, bool)

Helper method to get address from address pin configuration

View Source

Declaration

public static byte GetAddressFromPins(bool pinA0, bool pinA1, bool pinA2, bool isATypeDevice = false)

Returns

System.Byte: The device address

Parameters

Type	Name	Description
System.Boolean	pinA0	State of A0 address pin - true if high
System.Boolean	pinA1	State of A1 address pin - true if high
System.Boolean	pinA2	State of A2 address pin - true if high
System.Boolean	isATypeDevice	Is an A hardware variant, this shifts the address returned by 24

CreateDigitalOutputPort(IPin, bool, OutputType)

Creates an IDigitalOutputPort on the specified pin.

View Source

Declaration

public IDigitalOutputPort CreateDigitalOutputPort(IPin pin, bool initialState = false, OutputType initialOutputType = OutputType.PushPull)

Returns

Meadow.Hardware.IDigitalOutputPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin on which to create the port.
System.Boolean	initialState	The default initial state of the port,
either LOW (false), or HIGH (true).
Meadow.Hardware.OutputType	initialOutputType	Whether the port is initially configured
as PushPull or OpenDrain. PushPull by default.

CreateDigitalInputPort(IPin, ResistorMode)

Creates an IDigitalInputPort on the specified pin.

View Source

Declaration

public IDigitalInputPort CreateDigitalInputPort(IPin pin, ResistorMode resistorMode)

Returns

Meadow.Hardware.IDigitalInputPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin on which to create the port.
Meadow.Hardware.ResistorMode	resistorMode	The ResistorMode specifying whether an

        external pull-up/pull-down resistor is used, or an internal pull-up/pull-down
        resistor should be configured for default state. |

CreateDigitalInterruptPort(IPin, InterruptMode, ResistorMode)

Creates a new DigitalInputPort using the specified pin

View Source

Declaration

public IDigitalInterruptPort CreateDigitalInterruptPort(IPin pin, InterruptMode interruptMode = InterruptMode.None, ResistorMode resistorMode = ResistorMode.Disabled)

Returns

Meadow.Hardware.IDigitalInterruptPort: IDigitalInterruptPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin representing the port
Meadow.Hardware.InterruptMode	interruptMode	The port interrupt mode
Meadow.Hardware.ResistorMode	resistorMode	The port resistor mode

CreateDigitalInterruptPort(IPin, InterruptMode, ResistorMode, TimeSpan)

Creates a new DigitalInputPort using the specified pin

View Source

Declaration

public IDigitalInterruptPort CreateDigitalInterruptPort(IPin pin, InterruptMode interruptMode, ResistorMode resistorMode, TimeSpan debounceDuration)

Returns

Meadow.Hardware.IDigitalInterruptPort: IDigitalInterruptPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin representing the port
Meadow.Hardware.InterruptMode	interruptMode	The port interrupt mode
Meadow.Hardware.ResistorMode	resistorMode	The port resistor mode
System.TimeSpan	debounceDuration	The debounce duration

CreateDigitalInterruptPort(IPin, InterruptMode, ResistorMode, TimeSpan, TimeSpan)

Creates a new DigitalInputPort using the specified pin

View Source

Declaration

public IDigitalInterruptPort CreateDigitalInterruptPort(IPin pin, InterruptMode interruptMode, ResistorMode resistorMode, TimeSpan debounceDuration, TimeSpan glitchDuration)

Returns

Meadow.Hardware.IDigitalInterruptPort: IDigitalInterruptPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin representing the port
Meadow.Hardware.InterruptMode	interruptMode	The port interrupt mode
Meadow.Hardware.ResistorMode	resistorMode	The port resistor mode
System.TimeSpan	debounceDuration	The debounce duration
System.TimeSpan	glitchDuration	The glitch duration - not configurable on Mcpxxxx

GetPin(string)

View Source

Declaration

public abstract IPin GetPin(string pinName)

Returns

Meadow.Hardware.IPin

Parameters

Type	Name
System.String	pinName

IsValidPin(IPin)

Checks if a pin exists on the Pcx857x

View Source

Declaration

protected abstract bool IsValidPin(IPin pin)

Returns

System.Boolean

Parameters

Type	Name
Meadow.Hardware.IPin	pin

ReadState()

Reads the peripheral state register for 8 pin devices

View Source

Declaration

protected abstract ushort ReadState()

Returns

System.UInt16

WriteState(ushort)

Writes to the peripheral state register

View Source

Declaration

protected abstract void WriteState(ushort state)

Parameters

Type	Name
System.UInt16	state

SetState(ushort)

Writes to the peripheral state register and saves internal output state

View Source

Declaration

protected abstract void SetState(ushort state)

Parameters

Type	Name
System.UInt16	state

SetPinDirection(bool, byte)

Set the pin direction

View Source

Declaration

protected abstract void SetPinDirection(bool input, byte pinKey)

Parameters

Type	Name	Description
System.Boolean	input	true for input, false for output
System.Byte	pinKey	The pin key value

AllOff()

Convenience method to turn all outputs off

View Source

Declaration

public void AllOff()

AllOn()

Convenience method to turn all outputs on

View Source

Declaration

public void AllOn()

GetPinState(IPin)

Retrieves the state of a pin

View Source

Declaration

protected abstract bool GetPinState(IPin pin)

Returns

System.Boolean

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin to query

SetPinState(IPin, bool)

Sets the state of a pin

View Source

Declaration

protected abstract void SetPinState(IPin pin, bool state)

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin to affect
System.Boolean	state	<b>True</b> to set the pin state high, <b>False</b> to set it low

Dispose(bool)

Dispose of the object

View Source

Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing	Is disposing

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

View Source

Declaration

public void Dispose()

Implements

• Meadow.Hardware.IDigitalOutputController
• Meadow.Hardware.IDigitalInputController
• Meadow.Hardware.IDigitalInterruptController
• Meadow.Hardware.IPinController
• Meadow.Hardware.II2cPeripheral
• System.IDisposable