SpiConnectionSettings Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
public ref class SpiConnectionSettings sealed
/// [Windows.Foundation.Metadata.Activatable(Windows.Devices.Spi.ISpiConnectionSettingsFactory, 65536, Windows.Devices.DevicesLowLevelContract)]
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Devices.DevicesLowLevelContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class SpiConnectionSettings final
/// [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.Activatable(typeof(Windows.Devices.Spi.ISpiConnectionSettingsFactory), 65536, typeof(Windows.Devices.DevicesLowLevelContract))]
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Devices.DevicesLowLevelContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public sealed class SpiConnectionSettings
[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
- Inheritance
- Attributes
Windows requirements
Device family |
Windows IoT Extension SDK (introduced in 10.0.10240.0)
|
API contract |
Windows.Devices.DevicesLowLevelContract (introduced in v1.0)
|
Examples
The following sample illustrates the basic functionality of this and other SPI APIs by showing how to open an SPI bus by friendly name using the default connection settings.
// 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);
}
}
}
}
The following sample shows how to use this and other SPI APIs to initialize an SPI device with non-default connection settings. It does so by reading the light-intensity from an analog Photocell connected to an 8-channel 10-bit ADC108S102 A/D Converter.
Note
This sample contains several settings specific to the above devices. You may need to change these settings to account for your specific device. For instance, Raspberry Pi devices support a max 8/9 bit length for 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);
}
}
Constructors
SpiConnectionSettings(Int32) |
Initializes new instance of SpiConnectionSettings. |
Properties
ChipSelectLine |
Gets or sets the chip select line for the connection to the SPI device. |
ClockFrequency |
Gets or sets the clock frequency for the connection. |
DataBitLength |
Gets or sets the bit length for data on this connection. |
Mode |
Gets or sets the SpiMode for this connection. |
SharingMode |
Gets or sets the sharing mode for the SPI connection. |