Adding power and brightness ramping back in

src/devices/absolutemotor.ts

@@ -44,6 +44,7 @@ export class AbsoluteMotor extends TachoMotor {
         if (this.isWeDo2SmartHub) {
             throw new Error("Absolute positioning is not available on the WeDo 2.0 Smart Hub");
         }
+        this.cancelEventTimer();
         return new Promise((resolve) => {
             this._busy = true;
             if (speed === undefined || speed === null) {
@@ -78,6 +79,7 @@ export class AbsoluteMotor extends TachoMotor {
         if (this.isWeDo2SmartHub) {
             throw new Error("Absolute positioning is not available on the WeDo 2.0 Smart Hub");
         }
+        this.cancelEventTimer();
         return new Promise((resolve) => {
             this._busy = true;
             let message;
@@ -97,6 +99,7 @@ export class AbsoluteMotor extends TachoMotor {
     }
 
     public async calibrateServo () {
+        this.cancelEventTimer();
         const oldMode = this.mode;
         let currentAngle = 0;
         const listener = ({ angle }: { angle: number }) => {
@@ -142,6 +145,7 @@ export class AbsoluteMotor extends TachoMotor {
     }
 
     public async resetServo (angle: number) {
+        this.cancelEventTimer();
         const oldMode = this.mode;
         let currentAngle = 0;
         const listener = ({ angle }: { angle: number }) => {

src/devices/basicmotor.ts

@@ -4,7 +4,7 @@ import { IDeviceInterface } from "../interfaces";
 
 import * as Consts from "../consts";
 
-import { mapSpeed } from "../utils";
+import { calculateRamp, mapSpeed } from "../utils";
 
 export class BasicMotor extends Device {
 
@@ -20,7 +20,10 @@ export class BasicMotor extends Device {
      * @param {number} power For forward, a value between 1 - 100 should be set. For reverse, a value between -1 to -100. Stop is 0.
      * @returns {Promise} Resolved upon successful completion of command.
      */
-    public setPower (power: number) {
+    public setPower (power: number, interrupt: boolean = true) {
+        if (interrupt) {
+            this.cancelEventTimer();
+        }
         return new Promise((resolve) => {
             this.writeDirect(0x00, Buffer.from([mapSpeed(power)]));
             return resolve();
@@ -28,12 +31,33 @@ export class BasicMotor extends Device {
     }
 
 
+    /**
+     * Ramp the motor power.
+     * @method BasicMotor#rampPower
+     * @param {number} fromPower For forward, a value between 1 - 100 should be set. For reverse, a value between -1 to -100. Stop is 0.
+     * @param {number} toPower For forward, a value between 1 - 100 should be set. For reverse, a value between -1 to -100. Stop is 0.
+     * @param {number} time How long the ramp should last (in milliseconds).
+     * @returns {Promise} Resolved upon successful completion of command.
+     */
+    public rampPower (fromPower: number, toPower: number, time: number) {
+        this.cancelEventTimer();
+        return new Promise((resolve) => {
+            calculateRamp(this, fromPower, toPower, time)
+            .on("changePower", (power) => {
+                this.setPower(power, false);
+            })
+            .on("finished", resolve);
+        });
+    }
+
+
     /**
      * Stop the motor.
      * @method BasicMotor#stop
      * @returns {Promise} Resolved upon successful completion of command.
      */
     public stop () {
+        this.cancelEventTimer();
         return this.setPower(0);
     }
 
@@ -44,6 +68,7 @@ export class BasicMotor extends Device {
      * @returns {Promise} Resolved upon successful completion of command.
      */
     public brake () {
+        this.cancelEventTimer();
         return this.setPower(127);
     }
 

src/devices/device.ts

@@ -20,6 +20,7 @@ export class Device extends EventEmitter {
 
     private _isWeDo2SmartHub: boolean;
     private _isVirtualPort: boolean = false;
+    private _eventTimer: NodeJS.Timer | null = null;
 
     constructor (hub: IDeviceInterface, portId: number, modeMap: {[event: string]: number} = {}, type: Consts.DeviceType = Consts.DeviceType.UNKNOWN) {
         super();
@@ -136,6 +137,17 @@ export class Device extends EventEmitter {
         }
     }
 
+    public setEventTimer (timer: NodeJS.Timer) {
+        this._eventTimer = timer;
+    }
+
+    public cancelEventTimer () {
+        if (this._eventTimer) {
+            clearTimeout(this._eventTimer);
+            this._eventTimer = null;
+        }
+    }
+
     private _ensureConnected () {
         if (!this.connected) {
             throw new Error("Device is not connected");

src/devices/light.ts

@@ -3,6 +3,7 @@ import { Device } from "./device";
 import { IDeviceInterface } from "../interfaces";
 
 import * as Consts from "../consts";
+import { calculateRamp } from "../utils";
 
 export class Light extends Device {
 
@@ -14,11 +15,14 @@ export class Light extends Device {
 
     /**
      * Set the light brightness.
-     * @method Light#brightness
+     * @method Light#setBrightness
      * @param {number} brightness Brightness value between 0-100 (0 is off)
      * @returns {Promise} Resolved upon successful completion of command.
      */
-    public setBrightness (brightness: number) {
+    public setBrightness (brightness: number, interrupt: boolean = true) {
+        if (interrupt) {
+            this.cancelEventTimer();
+        }
         return new Promise((resolve) => {
             this.writeDirect(0x00, Buffer.from([brightness]));
             return resolve();
@@ -26,4 +30,24 @@ export class Light extends Device {
     }
 
 
+    /**
+     * Ramp the light brightness.
+     * @method Light#rampBrightness
+     * @param {number} fromBrightness Brightness value between 0-100 (0 is off)
+     * @param {number} toBrightness Brightness value between 0-100 (0 is off)
+     * @param {number} time How long the ramp should last (in milliseconds).
+     * @returns {Promise} Resolved upon successful completion of command.
+     */
+    public rampBrightness (fromBrightness: number, toBrightness: number, time: number) {
+        this.cancelEventTimer();
+        return new Promise((resolve) => {
+            calculateRamp(this, fromBrightness, toBrightness, time)
+            .on("changePower", (power) => {
+                this.setBrightness(power, false);
+            })
+            .on("finished", resolve);
+        });
+    }
+
+
 }

src/devices/tachomotor.ts

@@ -40,6 +40,7 @@ export class TachoMotor extends BasicMotor {
         if (this.isWeDo2SmartHub) {
             throw new Error("Motor speed is not available on the WeDo 2.0 Smart Hub");
         }
+        this.cancelEventTimer();
         return new Promise((resolve) => {
             this._busy = true;
             if (speed === undefined || speed === null) {
@@ -81,6 +82,7 @@ export class TachoMotor extends BasicMotor {
         if (this.isWeDo2SmartHub) {
             throw new Error("Rotation is not available on the WeDo 2.0 Smart Hub");
         }
+        this.cancelEventTimer();
         return new Promise((resolve) => {
             this._busy = true;
             if (speed === undefined || speed === null) {

src/utils.ts

@@ -1,3 +1,6 @@
+import { EventEmitter } from "events";
+import { Device } from "./devices/device";
+
 // @ts-ignore
 export const isWebBluetooth = (typeof navigator !== "undefined" && navigator && navigator.bluetooth);
 
@@ -55,3 +58,33 @@ export const roundAngleToNearest90 = (angle: number) => {
     }
     return -180;
 };
+
+export const calculateRamp = (device: Device, fromPower: number, toPower: number, time: number) => {
+    const emitter = new EventEmitter();
+    const steps = Math.abs(toPower - fromPower);
+    let delay = time / steps;
+    let increment = 1;
+    if (delay < 50 && steps > 0) {
+        increment = 50 / delay;
+        delay = 50;
+    }
+    if (fromPower > toPower) {
+        increment = -increment;
+    }
+    let i = 0;
+    const interval = setInterval(() => {
+        let power = Math.round(fromPower + (++i * increment));
+        if (toPower > fromPower && power > toPower) {
+            power = toPower;
+        } else if (fromPower > toPower && power < toPower) {
+            power = toPower;
+        }
+        emitter.emit("changePower", power);
+        if (power === toPower) {
+            clearInterval(interval);
+            emitter.emit("finished");
+        }
+    }, delay);
+    device.setEventTimer(interval);
+    return emitter;
+};