Remarks
| RgbPwmLed | |
|---|---|
| Status |  |
| Source code | GitHub |
| NuGet package |  |
RgbPwmLed represents an RGB LED whose color is controlled by the duty-cycle of three PWM signals. Can be used both with LEDs that have been current limited with in-series resistors, or LEDs without resistors.
Controlling an RGB LED via a PWM signal is more power efficient than using a current-limiting resistor, and it provides more control; allowing thousands of different colors, as opposed to the 8 colors of non-PWM powered RGB LED.
To use without resistors, pass in the forward voltages (voltage drop) of each of the LED components to the redLedForwardVoltage, greenLedForwardVoltage, and blueLedForwardVoltage, constructor parameters, and the class will limit its output to the maximum forward voltage rating for those LEDs.
To use with an LED that has a resistor in series, pass 0.0 or TypicalForwardVoltage.ResistorLimited for the forwardVoltage parameter.
Code Example
RgbPwmLed onboardLed;
public override Task Initialize()
{
Console.WriteLine("Creating peripherals...");
onboardLed = new RgbPwmLed(
Device,
Device.Pins.OnboardLedRed,
Device.Pins.OnboardLedGreen,
Device.Pins.OnboardLedBlue,
commonType: CommonType.CommonAnode);
return Task.CompletedTask;
}
public override Task Run()
{
TestColors();
RunColors();
return Task.CompletedTask;
}
public void TestColors()
{
onboardLed.SetColor(Color.Crimson);
Thread.Sleep(3000);
onboardLed.SetColor(Color.MediumPurple);
Thread.Sleep(3000);
onboardLed.SetColor(Color.FromHex("#23abe3"));
}
public void RunColors()
{
while (true) {
// loop through the entire hue spectrum (360 degrees)
for (int i = 0; i < 360; i++) {
var hue = ((double)i / 360F);
Console.WriteLine($"Hue: {hue}");
// set the color of the RGB
onboardLed.SetColor(Color.FromHsba((hue), 1, 1));
Thread.Sleep(18);
}
}
}
Sample project(s) available on GitHub
Example Code
The following example code loops through the entire 360º of hue spectrum and displays that color on the RGB LED.
public MeadowApp : App<F7Micro, MeadowApp>
{
public MeadowApp()
{
// create a new RgbPwmLed on pin 8
var pwmLed = new RgbPwmLed(
redPin: Device.Pins.D11,
greenPin: Device.Pins.D10,
bluePin: Device.Pins.D09,
redLedForwardVoltage: 1.05f,
greenLedForwardVoltage: 1.5f,
blueLedForwardVoltage: 1.5f);
);
// alternate between blinking and pulsing the LED
while (true)
{
for (int i = 0; i < 360; i++)
{
var hue = ((double)i / 360F);
Debug.Print(hue.ToString());
// set the color of the RGB
rgbPwmLed.SetColor(Color.FromHsba(((double)i / 360F), 1, 1));
// for a fun, fast rotation through the hue spectrum:
//Thread.Sleep (1);
// for a gentle walk through the forest of colors;
Thread.Sleep(18);
}
}
}
}
Sample projects available on GitHub
Wiring Example
<img src="../../API_Assets/Meadow.Foundation.Leds.RgbPwmLed/RgbPwmLed_Fritzing.svg"
| Characteristic | Locus |
|---|---|
| Inheritance | System.Object > RgbPwmLed |
| Namespace | Meadow.Foundation.Leds |
| Assembly | Meadow.Foundation.dll |
Syntax
public class RgbPwmLed : objectConstructors
RgbPwmLed(IPwmOutputController, IPin, IPin, IPin, CommonType)
Create instance of RgbPwmLed
Declaration
public RgbPwmLed(IPwmOutputController device, IPin redPwmPin, IPin greenPwmPin, IPin bluePwmPin, CommonType commonType = null)Parameters
| Type | Name | Description |
|---|---|---|
| IPwmOutputController | device | |
| IPin | redPwmPin | |
| IPin | greenPwmPin | |
| IPin | bluePwmPin | |
| CommonType | commonType |
RgbPwmLed(IPwmOutputController, IPin, IPin, IPin, Voltage, Voltage, Voltage, CommonType)
Instantiates a RgbPwmLed object with the especified IO device, connected to three digital pins for red, green and blue channels, respectively
Declaration
public RgbPwmLed(IPwmOutputController device, IPin redPwmPin, IPin greenPwmPin, IPin bluePwmPin, Voltage redLedForwardVoltage, Voltage greenLedForwardVoltage, Voltage blueLedForwardVoltage, CommonType commonType = null)Parameters
| Type | Name | Description |
|---|---|---|
| IPwmOutputController | device | |
| IPin | redPwmPin | |
| IPin | greenPwmPin | |
| IPin | bluePwmPin | |
| Voltage | redLedForwardVoltage | |
| Voltage | greenLedForwardVoltage | |
| Voltage | blueLedForwardVoltage | |
| CommonType | commonType |
RgbPwmLed(IPwmPort, IPwmPort, IPwmPort, CommonType)
Create instance of RgbPwmLed
Declaration
public RgbPwmLed(IPwmPort redPwm, IPwmPort greenPwm, IPwmPort bluePwm, CommonType commonType = null)Parameters
| Type | Name | Description |
|---|---|---|
| IPwmPort | redPwm | |
| IPwmPort | greenPwm | |
| IPwmPort | bluePwm | |
| CommonType | commonType |
RgbPwmLed(IPwmPort, IPwmPort, IPwmPort, Voltage, Voltage, Voltage, CommonType)
Implementation notes: Architecturally, it would be much cleaner to construct this class as three PwmLeds. Then each one's implementation would be self-contained. However, that would require three additional threads during ON; one contained by each PwmLed. For this reason, I'm basically duplicating the functionality for all three in here.
Declaration
public RgbPwmLed(IPwmPort redPwm, IPwmPort greenPwm, IPwmPort bluePwm, Voltage redLedForwardVoltage, Voltage greenLedForwardVoltage, Voltage blueLedForwardVoltage, CommonType commonType = null)Parameters
| Type | Name | Description |
|---|---|---|
| IPwmPort | redPwm | |
| IPwmPort | greenPwm | |
| IPwmPort | bluePwm | |
| Voltage | redLedForwardVoltage | |
| Voltage | greenLedForwardVoltage | |
| Voltage | blueLedForwardVoltage | |
| CommonType | commonType |
Properties
BlueForwardVoltage
Get the blue LED forward voltage
Declaration
public Voltage BlueForwardVoltage { get; protected set; }Property Value
| Type | Description |
|---|---|
| Voltage |
BluePwm
Get the blue LED port
Declaration
protected IPwmPort BluePwm { get; set; }Property Value
| Type | Description |
|---|---|
| IPwmPort |
Brightness
The brightness value assigned to the LED relative to Color
Declaration
public float Brightness { get; protected set; }Property Value
| Type | Description |
|---|---|
| System.Single |
Color
The color the LED has been set to.
Declaration
public Color Color { get; protected set; }Property Value
| Type | Description |
|---|---|
| Color |
Common
Gets the common type
Declaration
public CommonType Common { get; protected set; }Property Value
| Type | Description |
|---|---|
| CommonType |
GreenForwardVoltage
Get the green LED forward voltage
Declaration
public Voltage GreenForwardVoltage { get; protected set; }Property Value
| Type | Description |
|---|---|
| Voltage |
GreenPwm
Get the green LED port
Declaration
protected IPwmPort GreenPwm { get; set; }Property Value
| Type | Description |
|---|---|
| IPwmPort |
IsOn
Turns on LED with current color or turns it off
Declaration
public bool IsOn { get; set; }Property Value
| Type | Description |
|---|---|
| System.Boolean |
MAX_FORWARD_VOLTAGE
Maximum forward voltage (3.3 Volts)
Declaration
public Voltage MAX_FORWARD_VOLTAGE { get; }Property Value
| Type | Description |
|---|---|
| Voltage |
MIN_FORWARD_VOLTAGE
Minimum forward voltage (0 Volts)
Declaration
public Voltage MIN_FORWARD_VOLTAGE { get; }Property Value
| Type | Description |
|---|---|
| Voltage |
RedForwardVoltage
Get the red LED forward voltage
Declaration
public Voltage RedForwardVoltage { get; protected set; }Property Value
| Type | Description |
|---|---|
| Voltage |
RedPwm
Get the red LED port
Declaration
protected IPwmPort RedPwm { get; set; }Property Value
| Type | Description |
|---|---|
| IPwmPort |
Methods
ResetPwms()
Resets all PWM ports
Declaration
protected void ResetPwms()SetColor(Color, Single)
Sets the current color of the LED.
Declaration
public void SetColor(Color color, float brightness = null)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | |
| System.Single | brightness |
StartBlink(Color, Single, Single)
Start the Blink animation which sets the brightness of the LED alternating between a low and high brightness setting.
Declaration
public void StartBlink(Color color, float highBrightness = 1F, float lowBrightness = 0F)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | |
| System.Single | highBrightness | |
| System.Single | lowBrightness |
StartBlink(Color, TimeSpan, TimeSpan, Single, Single)
Start the Blink animation which sets the brightness of the LED alternating between a low and high brightness setting, using the durations provided.
Declaration
public void StartBlink(Color color, TimeSpan onDuration, TimeSpan offDuration, float highBrightness = 1F, float lowBrightness = 0F)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | |
| TimeSpan | onDuration | |
| TimeSpan | offDuration | |
| System.Single | highBrightness | |
| System.Single | lowBrightness |
StartBlinkAsync(Color, TimeSpan, TimeSpan, Single, Single, CancellationToken)
Start blinking led
Declaration
protected Task StartBlinkAsync(Color color, TimeSpan onDuration, TimeSpan offDuration, float highBrightness, float lowBrightness, CancellationToken cancellationToken)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | color to blink |
| TimeSpan | onDuration | on duration in ms |
| TimeSpan | offDuration | off duration in ms |
| System.Single | highBrightness | maximum brightness |
| System.Single | lowBrightness | minimum brightness |
| CancellationToken | cancellationToken | token to cancel blink |
Returns
| Type | Description |
|---|---|
| Task |
StartPulse(Color, Single, Single)
Start the Pulse animation which gradually alternates the brightness of the LED between a low and high brightness setting.
Declaration
public void StartPulse(Color color, float highBrightness = null, float lowBrightness = 0.15F)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | |
| System.Single | highBrightness | |
| System.Single | lowBrightness |
StartPulse(Color, TimeSpan, Single, Single)
Start the Pulse animation which gradually alternates the brightness of the LED between a low and high brightness setting, using the durations provided.
Declaration
public void StartPulse(Color color, TimeSpan pulseDuration, float highBrightness = null, float lowBrightness = 0.15F)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | |
| TimeSpan | pulseDuration | |
| System.Single | highBrightness | |
| System.Single | lowBrightness |
StartPulseAsync(Color, TimeSpan, Single, Single, CancellationToken)
Start led pulsing
Declaration
protected Task StartPulseAsync(Color color, TimeSpan pulseDuration, float highBrightness, float lowBrightness, CancellationToken cancellationToken)Parameters
| Type | Name | Description |
|---|---|---|
| Color | color | color to pulse |
| TimeSpan | pulseDuration | pulse duration in ms |
| System.Single | highBrightness | maximum brightness |
| System.Single | lowBrightness | minimum brightness |
| CancellationToken | cancellationToken | token to cancel pulse |
Returns
| Type | Description |
|---|---|
| Task |
Stop()
Stops any running animations.
Declaration
public void Stop()