/// <summary>
/// Constructs SenseHat instance
/// </summary>
public SenseHat(I2cBus?i2cBus = null, bool shouldDispose = false)
{
_shouldDispose = shouldDispose || i2cBus == null;
_i2cBus = i2cBus ?? I2cBus.Create(DefaultI2cBusId);
Debug.Assert(SenseHatLedMatrixI2c.I2cAddress == SenseHatJoystick.I2cAddress, $"Default addresses for {nameof(SenseHatLedMatrixI2c)} and {nameof(SenseHatJoystick)} were expected to be the same");
I2cDevice joystickAndLedMatrixI2cDevice = _i2cBus.CreateDevice(SenseHatLedMatrixI2c.I2cAddress);
_ledMatrix = new SenseHatLedMatrixI2c(joystickAndLedMatrixI2cDevice);
_joystick = new SenseHatJoystick(joystickAndLedMatrixI2cDevice);
_gyro = new SenseHatAccelerometerAndGyroscope(_i2cBus.CreateDevice(SenseHatAccelerometerAndGyroscope.I2cAddress));
_mag = new SenseHatMagnetometer(_i2cBus.CreateDevice(SenseHatMagnetometer.I2cAddress));
_temp = new SenseHatTemperatureAndHumidity(_i2cBus.CreateDevice(SenseHatTemperatureAndHumidity.I2cAddress));
_press = new SenseHatPressureAndTemperature(_i2cBus.CreateDevice(SenseHatPressureAndTemperature.I2cAddress));
}
public static Bme280 CreateBme280(I2cBus i2cBus)
{
var bme280 = new Bme280(i2cBus.CreateDevice(Bme280.DefaultI2cAddress));
SetupBme280(bme280);
return(bme280);
}
/// <summary>
/// Creates a device on this bus
/// </summary>
/// <param name="deviceAddress">The device address</param>
/// <returns>An I2C device</returns>
/// <remarks>No test is performed whether the given device exists and is usable</remarks>
public override I2cDevice CreateDevice(int deviceAddress)
{
if (_devices.TryGetValue(deviceAddress, out var device))
{
return(device);
}
var newDevice = _busInstance.CreateDevice(deviceAddress);
_devices.Add(deviceAddress, newDevice);
return(newDevice);
}
public static GpioExpander GetGpioExpander(this I2cBus bus, int address = GpioExpander.DefaultAddress)
{
if (bus is null)
{
throw ThrowHelper.ArgumentNullException(nameof(bus));
}
if (address is < 0 or > 127)
{
throw ThrowHelper.ArgumentOutOfRangeException(nameof(address), address);
}
return(new RaspberryPiExpander(bus.CreateDevice(address)));
}
/// <summary>
/// Create an I2C device instance on a default bus.
/// </summary>
/// <param name="connectionSettings">Connection parameters (contains I2C address and bus number)</param>
/// <returns>An I2C device instance</returns>
/// <remarks>This method can only be used for bus numbers where the corresponding pins are hardwired
/// (i.e. bus 0 and 1 on the Raspi always use pins 0/1 and 2/3)</remarks>
public I2cDevice CreateI2cDevice(I2cConnectionSettings connectionSettings)
{
Initialize();
// Returns logical pin numbers for the selected bus (or an exception if using a bus number > 1, because that
// requires specifying the pins)
if (_i2cBuses.TryGetValue(connectionSettings.BusId, out var bus))
{
return(bus.CreateDevice(connectionSettings.DeviceAddress));
}
int[] pinAssignment = GetDefaultPinAssignmentForI2c(connectionSettings.BusId);
I2cBus newBus = CreateOrGetI2cBus(connectionSettings.BusId, pinAssignment);
return(newBus.CreateDevice(connectionSettings.DeviceAddress));
}
/// <summary>
/// Performs a scan on the I2C bus, returning the addresses for all connected devices.
/// </summary>
/// <param name="bus">The bus to scan</param>
/// <param name="lowest">The lowest address to scan. Default 0x03</param>
/// <param name="highest">The highest address to scan. Default 0x77</param>
/// <returns>A list of bus addresses that are in use, an empty list if no device was found</returns>
/// <remarks>This method should never throw an exception. Bus scanning may interfere with normal device operation,
/// so this should not be done while devices are being used.</remarks>
public static List <int> PerformBusScan(this I2cBus bus, int lowest = 0x3, int highest = 0x77)
{
List <int> ret = new List <int>();
for (int addr = lowest; addr <= highest; addr++)
{
try
{
using (var device = bus.CreateDevice(addr))
{
device.ReadByte(); // Success means that this does not throw an exception
ret.Add(addr);
}
}
catch (Exception x) when(x is IOException || x is UnauthorizedAccessException)
{
// Ignore and continue
}
}
return(ret);
}
