feat(led-ring): add LED ring element

customizable number of pixels, background color and pixel spacing

Author: urish

src/index.ts

@@ -20,3 +20,4 @@ export { DHT22Element as Dht22Element } from './dht22-element';
 export { ArduinoMegaElement } from './arduino-mega-element';
 export { ArduinoNanoElement } from './arduino-nano-element';
 export { Ds1307Element } from './ds1307-element';
+export { LEDRingElement } from './led-ring-element';

src/led-ring-element.stories.ts

@@ -0,0 +1,40 @@
+import { html } from 'lit-html';
+import './led-ring-element';
+
+export default {
+  title: 'LED Ring',
+  component: 'wokwi-led-ring',
+  argTypes: {
+    animation: { control: 'boolean' },
+    pixels: { control: { type: 'number', min: 1, max: 64, step: 1 } },
+    pixelSpacing: { control: { type: 'range', min: 0, max: 10, step: 0.1 } },
+    background: { control: { type: 'color' } },
+    pinInfo: { control: { type: null } },
+  },
+  args: {
+    background: '#363',
+    pixels: 16,
+    pixelSpacing: 0,
+    animation: true,
+  },
+};
+
+const Template = ({ animation, background, pixels, pixelSpacing }) =>
+  html`<wokwi-led-ring
+    .animation=${animation}
+    background=${background}
+    pixels=${pixels}
+    pixelSpacing=${pixelSpacing}
+  ></wokwi-led-ring>`;
+
+export const Ring8 = Template.bind({});
+Ring8.args = { pixels: 8 };
+
+export const Ring12 = Template.bind({});
+Ring12.args = { pixels: 12 };
+
+export const Ring16 = Template.bind({});
+Ring16.args = { pixels: 16 };
+
+export const Ring24 = Template.bind({});
+Ring24.args = { pixels: 24 };

src/led-ring-element.ts

@@ -0,0 +1,152 @@
+import { customElement, html, LitElement, property, queryAll, svg } from 'lit-element';
+import { ElementPin } from './pin';
+import { RGB } from './types/rgb';
+
+const pinHeight = 3;
+const pcbWidth = 6;
+
+@customElement('wokwi-led-ring')
+export class LEDRingElement extends LitElement {
+  /**
+   * Number of pixels to in the LED ring
+   */
+  @property() pixels = 16;
+
+  /**
+   * Space between pixels (in mm)
+   */
+  @property({ type: Number }) pixelSpacing = 0;
+
+  /**
+   * Background (PCB) color
+   */
+  @property() background = '#363';
+
+  /**
+   * Animate the LEDs in the matrix. Used primarily for testing in Storybook.
+   * The animation sequence is not guaranteed and may change in future releases of
+   * this element.
+   */
+  @property() animation = false;
+
+  @queryAll('.pixel') pixelElements: SVGCircleElement[] = [];
+
+  private animationFrame: number | null = null;
+
+  get radius() {
+    return ((this.pixelSpacing + 5) * this.pixels) / 2 / Math.PI + pcbWidth;
+  }
+
+  get pinInfo(): ElementPin[] {
+    const { radius } = this;
+    const mmToPix = 3.78;
+    const pinSpacing = 2.54;
+    const y = (radius * 2 + pinHeight) * mmToPix;
+    const cx = radius * mmToPix;
+    const p = pinSpacing * mmToPix;
+
+    return [
+      {
+        name: 'GND',
+        x: cx - 1.5 * p,
+        y,
+        signals: [{ type: 'power', signal: 'GND' }],
+      },
+      { name: 'VCC', x: cx - 0.5 * p, y, signals: [{ type: 'power', signal: 'VCC' }] },
+      { name: 'DIN', x: cx + 0.5 * p, y, signals: [] },
+      { name: 'DOUT', x: cx + 1.5 * p, y, signals: [] },
+    ];
+  }
+
+  setPixel(pixel: number, { r, g, b }: RGB) {
+    const { pixelElements } = this;
+    if (pixel < 0 || pixel >= pixelElements.length) {
+      return;
+    }
+    pixelElements[pixel].style.fill = `rgb(${r * 255},${g * 255},${b * 255})`;
+  }
+
+  /**
+   * Resets all the pixels to off state (r=0, g=0, b=0).
+   */
+  reset() {
+    for (const element of this.pixelElements) {
+      element.style.fill = '';
+    }
+  }
+
+  private animateStep = () => {
+    const time = new Date().getTime();
+    const { pixels } = this;
+    const pixelValue = (n: number) => (n % 2000 > 1000 ? 1 - (n % 1000) / 1000 : (n % 1000) / 1000);
+    for (let pixel = 0; pixel < pixels; pixel++) {
+      this.setPixel(pixel, {
+        r: pixelValue(pixel * 100 + time),
+        g: pixelValue(pixel * 100 + time + 200),
+        b: pixelValue(pixel * 100 + time + 400),
+      });
+    }
+    this.animationFrame = requestAnimationFrame(this.animateStep);
+  };
+
+  updated() {
+    if (this.animation && !this.animationFrame) {
+      this.animationFrame = requestAnimationFrame(this.animateStep);
+    } else if (!this.animation && this.animationFrame) {
+      cancelAnimationFrame(this.animationFrame);
+      this.animationFrame = null;
+    }
+  }
+
+  render() {
+    const { pixels, radius, background } = this;
+    const pixelElements = [];
+    const width = radius * 2;
+    const height = radius * 2 + pinHeight;
+    for (let i = 0; i < pixels; i++) {
+      const angle = (i / pixels) * 360;
+      pixelElements.push(
+        svg`<rect
+          class="pixel"
+          x="${radius - 2.5}"
+          y="${pcbWidth / 2 - 2.5}"
+          width="5"
+          height="5"
+          fill="white"
+          stroke="black"
+          stroke-width="0.25"
+          transform="rotate(${angle} ${radius} ${radius})"/>`
+      );
+    }
+    return html`
+      <svg
+        width="${width}mm"
+        height="${height}mm"
+        version="1.1"
+        viewBox="0 0 ${width} ${height}"
+        xmlns="http://www.w3.org/2000/svg"
+      >
+        <defs>
+          <pattern id="pin-pattern" height="2" width="2.54" patternUnits="userSpaceOnUse">
+            <rect x="1.02" y="0" height="2" width="0.5" fill="#aaa" />
+          </pattern>
+        </defs>
+        <rect
+          fill="url(#pin-pattern)"
+          height="${pinHeight + 1}"
+          width=${4 * 2.54}
+          transform="translate(${radius - (4 * 2.54) / 2}, ${radius * 2 - 1})"
+        />
+        <circle
+          cx="${radius}"
+          cy="${radius}"
+          r="${radius - pcbWidth / 2}"
+          fill="transparent"
+          stroke-width="${pcbWidth}"
+          stroke="${background}"
+        />
+        ${pixelElements}
+      </svg>
+    `;
+  }
+}

src/neopixel-matrix-element.ts

@@ -1,15 +1,10 @@
 import { css, customElement, html, LitElement, property, svg } from 'lit-element';
 import { ElementPin, GND, VCC } from './pin';
+import { RGB } from './types/rgb';
 
 const pixelWidth = 5.66;
 const pixelHeight = 5;
 
-export interface RGB {
-  r: number;
-  g: number;
-  b: number;
-}
-
 /**
  * Renders a matrix of NeoPixels (smart RGB LEDs).
  * Optimized for displaying large matrices (up to thousands of elements).

src/react-types.ts

@@ -19,6 +19,7 @@ import { DHT22Element } from './dht22-element';
 import { ArduinoMegaElement } from './arduino-mega-element';
 import { ArduinoNanoElement } from './arduino-nano-element';
 import { Ds1307Element } from './ds1307-element';
+import { LEDRingElement } from './led-ring-element';
 
 declare global {
   namespace JSX {
@@ -41,6 +42,7 @@ declare global {
       'wokwi-arduino-mega': Partial<ArduinoMegaElement>;
       'wokwi-arduino-nano': Partial<ArduinoNanoElement>;
       'wokwi-ds1307': Partial<Ds1307Element>;
+      'wokwi-neopixel-ring': Partial<LEDRingElement>;
     }
   }
 }

src/types/rgb.ts

@@ -0,0 +1,5 @@
+export interface RGB {
+  r: number;
+  g: number;
+  b: number;
+}