Class Mcp23xxx
Provide an interface to connect to a MCP23xxx port expander
Assembly: Mcp23xxx.dll
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public abstract class Mcp23xxx : IDigitalInputOutputController, IDigitalInputController, IDigitalOutputController, ISpiPeripheral, II2cPeripheral, IDigitalInterruptController, IPinController
Derived:
Meadow.Foundation.ICs.IOExpanders.Mcp23x0x, Meadow.Foundation.ICs.IOExpanders.Mcp23x1x
Implements:
Meadow.Hardware.IDigitalInputOutputController, Meadow.Hardware.IDigitalInputController, Meadow.Hardware.IDigitalOutputController, Meadow.Hardware.ISpiPeripheral, Meadow.Hardware.II2cPeripheral, Meadow.Hardware.IDigitalInterruptController, Meadow.Hardware.IPinController
Properties
NumberOfPins
The number of IO pins available on the device
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public abstract int NumberOfPins { get; }
DefaultSpiBusSpeed
The default SPI bus speed for the device
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public Frequency DefaultSpiBusSpeed { get; }
SpiBusSpeed
The SPI bus speed for the device
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public Frequency SpiBusSpeed { get; set; }
DefaultSpiBusMode
The default SPI bus mode for the device
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public SpiClockConfiguration.Mode DefaultSpiBusMode { get; }
SpiBusMode
The SPI bus mode for the device
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public SpiClockConfiguration.Mode SpiBusMode { get; set; }
DefaultI2cAddress
The default I2C address for the peripheral
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public byte DefaultI2cAddress { get; }
Fields
_lock
object for using lock() to do thread sync
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protected object _lock
Methods
GetAddressFromPins(bool, bool, bool)
Help method to get address from address pin configuration
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public static byte GetAddressFromPins(bool pinA0, bool pinA1, bool pinA2)
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 |
ResetMcp()
Reset the MCPxxxx expander Requires using a reset port
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public void ResetMcp()
IsValidPin(IPin)
Checks if a pin exists on the Mcp23xxx
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protected abstract bool IsValidPin(IPin pin)
Returns
System.Boolean
Parameters
| Type | Name |
|---|---|
Meadow.Hardware.IPin | pin |
CreateDigitalOutputPort(IPin, bool, OutputType)
Creates a new DigitalOutputPort using the specified pin and initial state
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public virtual IDigitalOutputPort CreateDigitalOutputPort(IPin pin, bool initialState = false, OutputType outputType = OutputType.OpenDrain)
Returns
Meadow.Hardware.IDigitalOutputPort: IDigitalOutputPort
Parameters
| Type | Name | Description |
|---|---|---|
Meadow.Hardware.IPin | pin | The pin representing the port |
System.Boolean | initialState | Whether the pin is initially high or low |
Meadow.Hardware.OutputType | outputType | The output type |
CreateDigitalInputPort(IPin, ResistorMode)
Creates a new DigitalInputPort using the specified pin
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public IDigitalInputPort CreateDigitalInputPort(IPin pin, ResistorMode resistorMode = ResistorMode.Disabled)
Returns
Meadow.Hardware.IDigitalInputPort: IDigitalInputPort
Parameters
| Type | Name | Description |
|---|---|---|
Meadow.Hardware.IPin | pin | The pin representing the port |
Meadow.Hardware.ResistorMode | resistorMode | The port resistor mode |
CreateDigitalInterruptPort(IPin, InterruptMode, ResistorMode)
Creates a new DigitalInputPort using the specified pin
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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
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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
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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 Mcp23xxx |
SetPortDirection(IPin, PortDirectionType)
Sets the direction of a port
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public void SetPortDirection(IPin pin, PortDirectionType direction)
Parameters
| Type | Name | Description |
|---|---|---|
Meadow.Hardware.IPin | pin | The pin representing the port |
Meadow.Hardware.PortDirectionType | direction | The port direction (input or output) |
WriteToPort(IPin, bool)
Sets a particular pin's value. If that pin is not in output mode, this method will first set its mode to output.
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public void WriteToPort(IPin pin, bool value)
Parameters
| Type | Name | Description |
|---|---|---|
Meadow.Hardware.IPin | pin | The pin to write to. |
System.Boolean | value | The value to write. True for high, false for low. |
ReadPort(IPin)
Gets the value of a particular port. If the port is currently configured as an output, this will change the configuration.
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public bool ReadPort(IPin pin)
Returns
System.Boolean
Parameters
| Type | Name |
|---|---|
Meadow.Hardware.IPin | pin |
WriteToPorts(byte)
Outputs a byte value across all of the pins by writing directly to the output latch (OLAT) register
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public void WriteToPorts(byte mask)
Parameters
| Type | Name |
|---|---|
System.Byte | mask |
ReadFromPorts(PortBank)
Reads a byte value from all of the pins. little-endian; the least significant bit is the value of GP0. So a byte value of 0x60, or 0110 0000, means that pins GP5 and GP6 are high.
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public byte ReadFromPorts(Mcp23xxx.PortBank bank = PortBank.A)
Returns
System.Byte: A little-endian byte mask of the pin values.
Parameters
| Type | Name |
|---|---|
| Meadow.Foundation.ICs.IOExpanders.Mcp23xxx.PortBank | bank |
ResetPin(IPin)
Sets the pin back to an input
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protected void ResetPin(IPin pin)
Parameters
| Type | Name |
|---|---|
Meadow.Hardware.IPin | pin |
GetPin(string)
Get Pin by name
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public abstract IPin GetPin(string pinName)
Returns
Meadow.Hardware.IPin: IPin object if found
Parameters
| Type | Name | Description |
|---|---|---|
System.String | pinName | The pin name |
Events
InputChanged
Raised when the value of any pin configured for input interrupts changes This provides raw port state data from the MCP23xxx It's highly recommended to prefer using the events exposed on the digital input ports instead.
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public event EventHandler<IOExpanderInputChangedEventArgs> InputChanged
Event Type
System.EventHandler<Meadow.Foundation.ICs.IOExpanders.IOExpanderInputChangedEventArgs>
Implements
Meadow.Hardware.IDigitalInputOutputControllerMeadow.Hardware.IDigitalInputControllerMeadow.Hardware.IDigitalOutputControllerMeadow.Hardware.ISpiPeripheralMeadow.Hardware.II2cPeripheralMeadow.Hardware.IDigitalInterruptControllerMeadow.Hardware.IPinController