Class AnalogInputPortBase
Provides a base implementation for much of the common tasks of implementing IAnalogInputPort
Assembly: Meadow.Contracts.dll
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public abstract class AnalogInputPortBase : AnalogPortBase, IAnalogInputPort, IAnalogPort, IPort<IAnalogChannelInfo>, IDisposable, IObservable<IChangeResult<Voltage>>
Inheritance: System.Object -> Meadow.Hardware.PortBase<C>
Derived:
Meadow.Hardware.AnalogInputPort
Implements:
Meadow.Hardware.IAnalogInputPort, System.IDisposable, System.IObservable<Meadow.IChangeResult<Meadow.Units.Voltage>>
Properties
BufferSyncRoot
Gets the internal synchronization object for the analog buffer
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protected object BufferSyncRoot { get; }
VoltageSampleBuffer
Gets the sample buffer. Make sure to call StartUpdating() before use.
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public Voltage[] VoltageSampleBuffer { get; }
UpdateInterval
A TimeSpan that specifies how long to
wait between readings. This value influences how often *Updated
events are raised and IObservable consumers are notified.
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public TimeSpan UpdateInterval { get; protected set; }
SampleCount
Number of samples to take per reading. If > 1 then the port will
take multiple readings and These are automatically averaged to
reduce noise, a process known as oversampling.
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public int SampleCount { get; protected set; }
SampleInterval
Duration in between samples when oversampling.
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public TimeSpan SampleInterval { get; protected set; }
ReferenceVoltage
The reference voltage being used for the ADC comparison
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public Voltage ReferenceVoltage { get; protected set; }
Voltage
Gets the average value of the values in the buffer. Use in conjunction with StartUpdating() for long-running analog sampling. For occasional sampling, use Read().
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public virtual Voltage Voltage { get; }
Observers
A collection of state observers
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protected List<IObserver<IChangeResult<Voltage>>> Observers { get; }
Methods
ConvertReadingToVoltage(int)
Converts a raw 32-bit reading to a scaled value in volts
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protected double ConvertReadingToVoltage(int rawReading)
Returns
System.Double
Parameters
| Type | Name | Description |
|---|---|---|
System.Int32 | rawReading | The raw reading to convert |
Read()
Convenience method to get the current voltage. For frequent reads, use StartUpdating() and StopUpdating() in conjunction with the SampleBuffer.
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public abstract Task<Voltage> Read()
Returns
System.Threading.Tasks.Task<Meadow.Units.Voltage>
StartUpdating(TimeSpan?)
Starts continuously sampling the analog port.
This method also starts raising Changed events and IObservable
subscribers getting notified. Use the readIntervalDuration parameter
to specify how often events and notifications are raised/sent.
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public abstract void StartUpdating(TimeSpan? updateInterval)
Parameters
| Type | Name |
|---|---|
System.Nullable<System.TimeSpan> | updateInterval |
StopUpdating()
Stops sampling the analog port.
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public abstract void StopUpdating()
RaiseChangedAndNotify(IChangeResult<Voltage>)
Raises the Changed event and notifies the observers with the specified change result.
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protected void RaiseChangedAndNotify(IChangeResult<Voltage> changeResult)
Parameters
| Type | Name | Description |
|---|---|---|
| Meadow.IChangeResult<UNIT> | changeResult | The change result to be passed to the event and observers. |
Subscribe(IObserver<IChangeResult<Voltage>>)
Subscribes an observer to receive notifications of voltage change.
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public IDisposable Subscribe(IObserver<IChangeResult<Voltage>> observer)
Returns
System.IDisposable: An IDisposable object that can be used to unsubscribe from the observer.
Parameters
| Type | Name | Description |
|---|---|---|
System.IObserver<Meadow.IChangeResult<Meadow.Units.Voltage>> | observer | The observer to subscribe. |
Events
Updated
Raised when the value of the reading changes.
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public event EventHandler<IChangeResult<Voltage>> Updated
Event Type
System.EventHandler<Meadow.IChangeResult<Meadow.Units.Voltage>>
Implements
- Meadow.Hardware.IAnalogInputPort
- Meadow.Hardware.IAnalogPort
- Meadow.Hardware.IPort<C>
System.IDisposableSystem.IObservable<Meadow.IChangeResult<Meadow.Units.Voltage>>