in sim/visuals/neopixel.ts [202:222]
public init(bus: EventBus, state: NeoPixelState, svgEl: SVGSVGElement, otherParams: Map<string>): void {
U.assert(!!otherParams["mode"], "NeoPixels assumes a RGB vs RGBW mode is passed to it");
U.assert(!!otherParams["pin"], "NeoPixels assumes a pin is passed to it");
let modeStr = otherParams["mode"];
this.mode = parseNeoPixelMode(modeStr);
this.state = state;
this.stripGroup = <SVGGElement>svg.elt("g");
this.element = this.stripGroup;
let pinStr = otherParams["pin"];
this.pin = digitalPinToPinNumber(pinStr);
this.lastLocation = [0, 0];
let part = mkNeoPixelPart();
this.part = part;
this.stripGroup.appendChild(part.el);
let canvas = new NeoPixelCanvas(this.pin);
this.canvas = canvas;
let canvasG = svg.elt("g", { class: "sim-neopixel-canvas-parent" });
this.overElement = canvasG;
canvasG.appendChild(canvas.canvas);
this.updateStripLoc();
}