SpiConnectionSettings 类

定义

命名空间:

Windows.Devices.Spi

表示与 SpiDevice 的连接的设置。

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

继承

Object Platform::Object IInspectable SpiConnectionSettings

属性

ActivatableAttribute ContractVersionAttribute MarshalingBehaviorAttribute

Windows 要求

设备系列	Windows IoT Extension SDK (在 10.0.10240.0 中引入)
API contract	Windows.Devices.DevicesLowLevelContract (在 v1.0 中引入)

示例

以下示例通过演示如何使用默认连接设置按友好名称打开 SPI 总线来演示此 API 和其他 SPI API 的基本功能。

// 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); 
            } 
        } 
    } 
} 

以下示例演示如何使用此 API 和其他 SPI API 通过非默认连接设置初始化 SPI 设备。 它通过读取连接到 8 通道 10 位 ADC108S102 A/D 转换器的模拟 Photocell 的光强度来实现。

注意

此示例包含多个特定于上述设备的设置。 可能需要更改这些设置，以考虑到你的特定设备。 例如，Raspberry Pi 设备支持 SPI 的最大 8/9 位长度。

// 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); 
    } 
} 

构造函数

SpiConnectionSettings(Int32)

初始化 SpiConnectionSettings 的新实例。

属性

ChipSelectLine	获取或设置用于连接到 SPI 设备的芯片选择线。
ClockFrequency	获取或设置连接的时钟频率。
DataBitLength	获取或设置此连接上数据的位长度。
Mode	获取或设置此连接的 SpiMode 。
SharingMode	获取或设置 SPI 连接的共享模式。