Gyro tutorials (#930)

* gyro tutorials

* tutorials

* fix gyro simulator

* images

* updated image

* fix svg errors

docs/tutorials.md

@@ -25,6 +25,11 @@ Step by step guides to coding your @boardname@.
   "description": "Use the color sensor to follow line or detect colors",
   "url":"/tutorials/color-sensor",
   "imageUrl":"/static/tutorials/what-color.png"
+}, {
+  "name": "Gyro",
+  "description": "Drive straight or turn more precisely with the gyro",
+  "url":"/tutorials/gyro",
+  "imageUrl":"/static/tutorials/calibrate-gyro.png"
 }, {
   "name": "Ultrasonic Sensor",
   "description": "Use the ultrasonic sensor to detect obstacles",

docs/tutorials/calibrate-gyro.md

@@ -0,0 +1,37 @@
+# Calibrate Gyro
+
+## Introduction @fullscreen
+
+The gyroscope is a very useful sensor in the EV3 system. It detects the rotation rate
+which can be very useful to correct the trajectory of the robot and do precise turns.
+
+However, the sensor can be imprecise and subject to drifting. It is recommend to
+calibrate your sensor at least once after starting your brick. You don't have to 
+recalibrate on every run.
+
+* [EV3 Driving Base](https://le-www-live-s.legocdn.com/sc/media/lessons/mindstorms-ev3/building-instructions/ev3-rem-driving-base-79bebfc16bd491186ea9c9069842155e.pdf)
+* [EV3 Driving Base with Gyro](https://le-www-live-s.legocdn.com/sc/media/lessons/mindstorms-ev3/building-instructions/ev3-gyro-sensor-driving-base-a521f8ebe355c281c006418395309e15.pdf)
+
+
+## Step 1 Show ports
+
+Add the ``||brick:show ports||`` to see the status of the gyroscope.
+
+```blocks
+brick.showPorts()
+```
+
+
+## Step 2 Calibration
+
+Add a ``||sensors:calibrate gyro||`` block to calibrate the gyro. The block
+detects if the sensor is present and does a full reset of the sensor if necessary.
+
+```blocks
+brick.showPorts()
+sensors.gyro2.calibrate()
+```
+
+## Step 3 Download and run @fullscreen
+
+Download this program to your brick and press the ENTER button.

docs/tutorials/gyro.md

@@ -0,0 +1,19 @@
+# Gyro tutorials
+
+## Tutorials
+
+```codecard
+[{
+  "name": "Calibrate",
+  "description": "Make sure you gyro sensor is ready to use",
+  "cardType": "tutorial",
+  "url":"/tutorials/calibrate-gyro",
+  "imageUrl":"/static/tutorials/calibrate-gyro.png"
+}, {
+  "name": "Move Straight",
+  "description": "Use the gyro to correct the trajectory of the robot",
+  "cardType": "tutorial",
+  "url":"/tutorials/move-straight-with-gyro",
+  "imageUrl":"/static/tutorials/move-straight-with-gyro.png"
+}]
+```

docs/tutorials/move-straight-with-gyro.md

@@ -0,0 +1,61 @@
+# Move Straight With Gyro
+
+## Introduction @fullscreen
+
+Rotating using a wheel is not precise. The wheel can slip or the motors
+can be slightly different. 
+With the help of the gyro you can detect and correct deviations in your trajectory.
+
+* [EV3 Driving Base](https://le-www-live-s.legocdn.com/sc/media/lessons/mindstorms-ev3/building-instructions/ev3-rem-driving-base-79bebfc16bd491186ea9c9069842155e.pdf)
+* [EV3 Driving Base with Gyro](https://le-www-live-s.legocdn.com/sc/media/lessons/mindstorms-ev3/building-instructions/ev3-gyro-sensor-driving-base-a521f8ebe355c281c006418395309e15.pdf)
+
+
+## Step 1 Calibration
+
+Add a ``||sensors:calibrate gyro||`` block in a ``||brick:on button enter pressed||`` block so that you can manually start a calibration process. Run the calibration
+at least once after connecting the gyro.
+
+```blocks
+brick.showPorts()
+sensors.gyro2.calibrate()
+```
+
+## Step 2 Compute the error
+
+Make a new **error** variable and drag the ``||sensors:gyro rate||``
+and multiply it by -1. Since the rate shows the rotation rate, we will
+counter it by negating it.
+
+```blocks
+let error = 0
+brick.showPorts()
+sensors.gyro2.calibrate()
+while (true) {
+    error = sensors.gyro2.rate() * -1
+}
+```
+
+## Step 3 Steer with feedback
+
+Drag a ``||motors:steer motors||`` block under the variable and pass
+the **error** variable into the turn ratio section.
+
+If the robot is turning right, the gyro will report a positive rotation rate
+and the turn ratio will be negative which will the turn the robot left!
+
+```blocks
+let error = 0
+brick.showPorts()
+sensors.gyro2.calibrate()
+while (true) {
+    error = sensors.gyro2.rate() * -1
+    motors.largeBC.steer(error, 50)
+}
+```
+
+## Step 4 Run it!
+
+Download to your brick and test out if the robot is going straight.
+
+This kind of technique is called a proportional controller; 
+it corrects the inputs (motor speed) with a feedback proportional to the output (rotation rate).

libs/gyro-sensor/docs/reference/sensors/gyro/calibrate.md

@@ -1,6 +1,6 @@
 # calibrate
 
-Reset the zero reference for the gyro to current position of the brick.
+Detects if the gyro is drifting and performs a full reset if needed.
 
 ```sig
 sensors.gyro2.calibrate()

libs/gyro-sensor/gyro.ts

@@ -73,7 +73,7 @@ namespace sensors {
         }
 
         /**
-         * Forces a calibration of the with light progress indicators. 
+         * Detects if calibration is necessary and performs a full reset, drift computation.
          * Must be called when the sensor is completely still.
          */
         //% help=sensors/gyro/calibrate
@@ -95,6 +95,19 @@ namespace sensors {
             // give time for robot to settle
             pause(700);
 
+            // compute drift
+            this.computeDriftNoCalibration();
+            if (Math.abs(this.drift()) < 0.1) {
+                // no drift, skipping calibration
+                brick.setStatusLight(StatusLight.Green); // success
+                pause(1000);
+                brick.setStatusLight(statusLight); // resture previous light
+
+                // and we're done
+                this.calibrating = false;
+                return;
+            }
+
             // calibrating
             brick.setStatusLight(StatusLight.OrangePulse);
 

sim/state/gyro.ts

@@ -1,5 +1,5 @@
 namespace pxsim {
-    const enum GyroSensorMode {
+    export const enum GyroSensorMode {
         None = -1,
         Angle = 0,
         Rate = 1,
@@ -20,6 +20,7 @@ namespace pxsim {
         }
 
         setAngle(angle: number) {
+            angle = angle | 0;
             if (this.angle != angle) {
                 this.angle = angle;
                 this.setChangedState();
@@ -27,6 +28,7 @@ namespace pxsim {
         }
 
         setRate(rate: number) {
+            rate = rate | 0;
             if (this.rate != rate) {
                 this.rate = rate;
                 this.setChangedState();

sim/visuals/controlView.ts

@@ -49,11 +49,13 @@ namespace pxsim.visuals {
         }
 
         private updateDimensions(width: number, height: number, strict?: boolean) {
+            width = Math.max(0, width);
+            height = Math.max(0, height);
             if (this.content) {
                 const currentWidth = this.getInnerWidth();
                 const currentHeight = this.getInnerHeight();
-                const newHeight = currentHeight / currentWidth * width;
+                const newHeight = Math.max(0, currentHeight / currentWidth * width);
-                const newWidth = currentWidth / currentHeight * height;
+                const newWidth = Math.max(0, currentWidth / currentHeight * height);
                 if (strict) {
                     this.content.setAttribute('width', `${width}`);
                     this.content.setAttribute('height', `${height}`);

sim/visuals/controls/rotationSlider.ts

@@ -1,13 +1,16 @@
 
 
 namespace pxsim.visuals {
+    const MAX_RATE = 40;
+    const MAX_ANGLE = 360;
 
     export class RotationSliderControl extends ControlView<GyroSensorNode> {
         private group: SVGGElement;
         private slider: SVGGElement;
+        private text: SVGTextElement;
 
         private static SLIDER_WIDTH = 70;
-        private static SLIDER_HEIGHT = 78;
+        //private static SLIDER_HEIGHT = 78;
 
         getInnerView(parent: SVGSVGElement, globalDefs: SVGDefsElement) {
             this.group = svg.elt("g") as SVGGElement;
@@ -23,6 +26,14 @@ namespace pxsim.visuals {
             pxsim.svg.child(this.slider, "circle", { 'cx': 9, 'cy': 50, 'r': 13, 'style': 'fill: #f12a21' });
             pxsim.svg.child(this.slider, "circle", { 'cx': 9, 'cy': 50, 'r': 12.5, 'style': 'fill: none;stroke: #b32e29' });
 
+            this.text = pxsim.svg.child(this.group, "text", {
+                'x': RotationSliderControl.SLIDER_WIDTH / 2, 
+                'y': RotationSliderControl.SLIDER_WIDTH * 1.2,
+                'text-anchor': 'middle', 'dominant-baseline': 'middle',
+                'style': 'font-size: 16px',
+                'class': 'sim-text inverted number'
+            }) as SVGTextElement;
+
             const dragSurface = svg.child(this.group, "rect", {
                 x: 0,
                 y: 0,
@@ -61,7 +72,17 @@ namespace pxsim.visuals {
                 return;
             }
             const node = this.state;
-            const percentage = node.getValue();
+            let percentage = 50;
+            if (node.getMode() == GyroSensorMode.Rate) {
+                const rate = node.getValue();
+                this.text.textContent = `${rate}°/s`
+                // cap rate at 40deg/s
+                percentage = 50 + Math.sign(rate) * Math.min(MAX_RATE, Math.abs(rate)) / MAX_RATE * 50;
+            } else {  //angle
+                const angle = node.getValue();
+                this.text.textContent = `${angle}°`
+                percentage = 50 + Math.sign(angle) * Math.min(MAX_ANGLE, Math.abs(angle)) / MAX_ANGLE * 50;
+            }
             const x = RotationSliderControl.SLIDER_WIDTH * percentage / 100;
             const y = Math.abs((percentage - 50) / 50) * 10;
             this.slider.setAttribute("transform", `translate(${x}, ${y})`);
@@ -73,8 +94,14 @@ namespace pxsim.visuals {
             const bBox = this.content.getBoundingClientRect();
             let t = Math.max(0, Math.min(1, (width + bBox.left / this.scaleFactor - cur.x / this.scaleFactor) / width))
 
+            t = -(t - 0.5) * 2; // [-1,1]
+
             const state = this.state;
-            state.setRate((1 - t) * (100));
+            if (state.getMode() == GyroSensorMode.Rate) {
+                state.setRate(MAX_RATE * t);
+            } else {
+                state.setAngle(MAX_ANGLE * t)
+            }
         }
     }
 

targetconfig.json

@@ -18,6 +18,7 @@
         "Touch Sensor Tutorials": "tutorials/touch-sensor",
         "Color Sensor Tutorials": "tutorials/color-sensor",
         "Ultrasonic Sensor Tutorials": "tutorials/ultrasonic-sensor",
+        "Gyro Sensor Tutorials": "tutorials/gyro",
         "Infrared Sensor Tutorials": "tutorials/infrared-sensor",
         "FLL / City Shaper": "tutorials/city-shaper",
         "Design Engineering": "design-engineering",