SpiConnectionSettings Classe

Definizione

Spazio dei nomi:

Windows.Devices.Spi

Rappresenta le impostazioni per la connessione con spiDevice.

public ref class SpiConnectionSettings sealed

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Devices.DevicesLowLevelContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Activatable(Windows.Devices.Spi.ISpiConnectionSettingsFactory, 65536, "Windows.Devices.DevicesLowLevelContract")]
class SpiConnectionSettings final

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Devices.DevicesLowLevelContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Activatable(typeof(Windows.Devices.Spi.ISpiConnectionSettingsFactory), 65536, "Windows.Devices.DevicesLowLevelContract")]
public sealed class SpiConnectionSettings

function SpiConnectionSettings(chipSelectLine)

Public NotInheritable Class SpiConnectionSettings

Ereditarietà

Object Platform::Object IInspectable SpiConnectionSettings

Attributi

ActivatableAttribute ContractVersionAttribute MarshalingBehaviorAttribute

Requisiti Windows

Famiglia di dispositivi	Windows IoT Extension SDK (è stato introdotto in 10.0.10240.0)
API contract	Windows.Devices.DevicesLowLevelContract (è stato introdotto in v1.0)

Esempio

L'esempio seguente illustra la funzionalità di base di questa e altre API SPI mostrando come aprire un bus SPI in base al nome descrittivo usando le impostazioni di connessione predefinite.

// Arduino SPIDigialPot example: http://arduino.cc/en/Tutorial/SPIDigitalPot 
// using digital potentiometer AD5206 the 50kohm variance 
async void Digipot_AD5206() 
{ 
    // Get a device selector query that will select buses with SP10 
    // property set on them (we expect only 1 SP10 bus at the end) 
    var spi0Aqs = SpiDevice.GetDeviceSelector("SPI0"); 
    // Find all buses using the AQS query formed above 
    var devicesInfo = await DeviceInformation.FindAllAsync(spi0Aqs); 

    // Construct time settings beforehand which can't be changed 
    // once a SPI device is created 
    const Int32 DigipotChipSelectLine = 0; 
    var settings = new SpiConnectionSettings(DigipotChipSelectLine); 

    // Ask the SPI bus to open a device with the connection settings 
    // provided. Once we go out of scope, the device will be released 
    using (var spiDev = await SpiDevice.FromIdAsync(devicesInfo[0].Id, settings)) 
    { 

        // data[0] is the channel address 
        // data[1] is the resistance step (0 - 255) 
        // 0 is max digipot resistance, and 255 is no resistance 
        byte[] data = { 0x0, 0x0 }; 

        // Go over the 6 channels of the digipot 
        for (byte channel = 0; channel < 6; ++channel) 
        { 
            data[0] = channel; 

            // Step the resistance on this channel from max to min 
            for (byte r = 0; r <= 255; ++r) 
            { 
                data[1] = r; 
                spiDev.Write(data); 
                await Task.Delay(100); 
            } 

            // Step the resistance on this channel from min to max 
            for (byte r = 255; r >= 0; --r) 
            { 
                data[1] = r; 
                spiDev.Write(data); 
                await Task.Delay(100); 
            } 
        } 
    } 
} 

L'esempio seguente illustra come usare questa e altre API SPI per inizializzare un dispositivo SPI con impostazioni di connessione non predefinite. Lo fa leggendo l'intensità della luce da una fotocell analogica connessa a un convertitore ADC108S102 A/D a 8 canali.

Nota

Questo esempio contiene diverse impostazioni specifiche per i dispositivi precedenti. Potrebbe essere necessario modificare queste impostazioni per tenere conto del dispositivo specifico. Ad esempio, i dispositivi Raspberry Pi supportano una lunghezza massima di 8/9 bit per SPI.

// Knowing that an SPI bus with 'spiBusId' exist, and has the ADC connected 
// on 'chipSelectLine', read a digital sample from some sensor wired to 'channel' 
async Task<int> AnalogRead_ADC108S102(string spiBusId, Int32 chipSelectLine, byte channel) 
{ 
    var settings = new SpiConnectionSettings(chipSelectLine); 

    // The defaults (4MHz, 8-bit, Mode0) will not work here according 
    // to the datasheet. 
    // e.g The datasheet specifies a clock freq range (8MHz - 16MHz) 
    settings.ClockFrequency = 8000000; 
    // CPOL=1, CPHA=1 
    settings.Mode = SpiMode.Mode3; 
    // Conversion happens on a 16-bit frame 
    settings.DataBitLength = 16; 
    // The ADC108S102 has 8 input analog channels, where each can be 
    // connected to a specific analog sensor and each sensor is 
    // used by a different application independently 
    // The IO requests to the SPI bus are implicitly synchronized 
    // by the driver model, plus that the ADC configuration is per 
    // 1 sampling read 
    settings.SharingMode = SpiSharingMode.Shared; 

    // Ask the SPI bus to open a shared device with the connection settings 
    // provided. 
    using (var spiDev = await SpiDevice.FromIdAsync(spiBusId, settings)) 
    { 
        if (spiDev == null) 
            return -1; 

        // Set up control register to get a conversion on a specific 
        // channel address 
        byte[] write16bitData = { (byte)(channel << 3), 0 }; 
        byte[] read16bitData = new byte[2]; 
        // The transfer is guaranteed to be atomic according to SpbCx model 
        spiDev.TransferFullDuplex(write16bitData, read16bitData); 

        ushort result = BitConverter.ToUInt16(read16bitData, 0); 
        // Get rid of the 2 LSB zeros and mask the 10-bit sampled value 
        return (int)((result >> 2) & 0x3ff); 
    } 
} 

Costruttori

SpiConnectionSettings(Int32)

Inizializza una nuova istanza di SpiConnectionSettings.

Proprietà

ChipSelectLine	Ottiene o imposta la riga di selezione del chip per la connessione al dispositivo SPI.
ClockFrequency	Ottiene o imposta la frequenza dell'orologio per la connessione.
DataBitLength	Ottiene o imposta la lunghezza del bit per i dati in questa connessione.
Mode	Ottiene o imposta SpiMode per questa connessione.
SharingMode	Ottiene o imposta la modalità di condivisione per la connessione SPI.