Remarks
| Si1145 | |
|---|---|
| Status |  |
| Source code | GitHub |
| Datasheet(s) | GitHub |
| NuGet package |  |
The SI1145 is a low power infrared, ultraviolet and ambient light sensor with an I2C interface.
- Ultraviolet / Infrared / ambient light sensor
- Proximity sensor
- Independent LED drivers
- I2C interface up to 3.4 MBps
Sample projects available on GitHub
Purchasing
The following application reads the sensor output Infrared, Ultraviolet and Visibility once per second and outputs the result on the output console:
Code Example
Si1145 sensor;
public override Task Initialize()
{
Resolver.Log.Info("Initialize...");
sensor = new Si1145(Device.CreateI2cBus());
// Example that uses an IObservable subscription to only be notified when the filter is satisfied
var consumer = Si1145.CreateObserver(
handler: result => Resolver.Log.Info($"Observer: filter satisifed: {result.New.VisibleLight?.Lux:N2}Lux, old: {result.Old?.VisibleLight?.Lux:N2}Lux"),
// only notify if the visible light changes by 100 lux (put your hand over the sensor to trigger)
filter: result => {
if (result.Old is { } old) { //c# 8 pattern match syntax. checks for !null and assigns var.
// returns true if > 100lux change
return ((result.New.VisibleLight.Value - old.VisibleLight.Value).Abs().Lux > 100);
}
return false;
});
sensor.Subscribe(consumer);
// classical .NET events can also be used:
sensor.Updated += (sender, result) => {
Resolver.Log.Info($" Visible Light: {result.New.VisibleLight?.Lux:N2}Lux");
Resolver.Log.Info($" Infrared Light: {result.New.Infrared?.Lux:N2}Lux");
Resolver.Log.Info($" UV Index: {result.New.UltravioletIndex:N2}Lux");
};
return Task.CompletedTask;
}
public override async Task Run()
{
var (VisibleLight, UltravioletIndex, Infrared) = await sensor.Read();
Resolver.Log.Info("Initial Readings:");
Resolver.Log.Info($" Visible Light: {VisibleLight?.Lux:N2}Lux");
Resolver.Log.Info($" Infrared Light: {Infrared?.Lux:N2}Lux");
Resolver.Log.Info($" UV Index: {UltravioletIndex:N2}Lux");
sensor.StartUpdating(TimeSpan.FromSeconds(1));
}
Sample project(s) available on GitHub
Wiring Example
Syntax
public class Si1145 : ByteCommsSensorBase<(Illuminance? VisibleLight, double? UltravioletIndex, Illuminance? Infrared)>, ISamplingSensor<(Illuminance? VisibleLight, double? UltravioletIndex, Illuminance? Infrared)>, ISamplingSensor<(Illuminance? VisibleLight, double? UltravioletIndex, Illuminance? Infrared)>, IDisposableConstructors
Si1145(II2cBus)
Create a new SI1145 sensor object
Declaration
public Si1145(II2cBus i2cBus)Parameters
| Type | Name | Description |
|---|---|---|
| II2cBus | i2cBus | I2cBus (default to 400 KHz) |
Methods
ReadSensor()
Read data from the sensor
Declaration
protected override Task<(Illuminance? VisibleLight, double? UltravioletIndex, Illuminance? Infrared)> ReadSensor()Returns
| Type | Description |
|---|---|
| Task<System.ValueTuple<System.Nullable<Illuminance>, System.Nullable<System.Double>, System.Nullable<Illuminance>>> | Returns visible, ultraviolet index and ifrared data |
Overrides
Meadow.Foundation.SamplingSensorBase<System.ValueTuple<System.Nullable<Illuminance>, System.Nullable<System.Double>, System.Nullable<Illuminance>>>.ReadSensor()