internal static I2cDevice FindDevice(I2cController controller, int index)
{
for (int i = 0; i < controller.DeviceCollection.Count; i++)
{
if (((I2cDevice)controller.DeviceCollection[i])._deviceId == index)
{
return((I2cDevice)controller.DeviceCollection[i]);
}
}
return(null);
}
internal I2cDevice(string i2cBus, I2cConnectionSettings settings)
{
// generate a unique ID for the device by joining the I2C bus ID and the slave address, should be pretty unique
// the encoding is (I2C bus number x 1000 + slave address)
// i2cBus is an ASCII string with the bus name in format 'I2Cn'
// need to grab 'n' from the string and convert that to the integer value from the ASCII code (do this by subtracting 48 from the char value)
var controllerId = i2cBus[3] - 48;
var deviceId = (controllerId * deviceUniqueIdMultiplier) + settings.SlaveAddress;
I2cController controller;
if (!I2cControllerManager.ControllersCollection.Contains(controllerId))
{
// this controller doesn't exist yet, create it...
controller = new I2cController(i2cBus);
}
else
{
// get the controller from the collection...
controller = (I2cController)I2cControllerManager.ControllersCollection[controllerId];
}
// check if this device ID already exists
if (!controller.DeviceCollection.Contains(deviceId))
{
// device doesn't exist, create it...
_connectionSettings = new I2cConnectionSettings(settings.SlaveAddress)
{
BusSpeed = settings.BusSpeed,
SharingMode = settings.SharingMode
};
// save device ID
_deviceId = deviceId;
// call native init to allow HAL/PAL inits related with I2C hardware
NativeInit();
// ... and add this device
controller.DeviceCollection.Add(deviceId, this);
_syncLock = new object();
}
else
{
// this device already exists, throw an exception
throw new I2cDeviceAlreadyInUseException();
}
}
private void Dispose(bool disposing)
{
if (!_disposed)
{
bool disposeController = false;
if (disposing)
{
// get the controller
var controller = I2cController.FindController(_deviceId / deviceUniqueIdMultiplier);
if (controller != null)
{
// find device
var device = FindDevice(controller, _deviceId);
if (device != null)
{
// remove from device collection
controller.DeviceCollection.Remove(device);
// it's OK to also remove the controller, if there is no other device associated
if (controller.DeviceCollection.Count == 0)
{
I2cControllerManager.ControllersCollection.Remove(controller);
// flag this to native dispose
disposeController = true;
}
}
}
}
NativeDispose(disposeController);
_disposed = true;
}
}
/// <summary>
/// Retrieves an Advanced Query Syntax (AQS) string for all of the inter-integrated circuit (I2C) bus controllers on the system. You can use this string with the DeviceInformation.FindAll
/// method to get DeviceInformation objects for those bus controllers.
/// </summary>
/// <returns>An AQS string for all of the I2C bus controllers on the system, which you can use with the DeviceInformation.FindAllAsync method to get DeviceInformation
/// objects for those bus controllers.</returns>
public static string GetDeviceSelector()
{
return(I2cController.GetDeviceSelector());
}
