Battery monitor for M5Paper

main.js

/*
 * Copyright (c) 2016-2022  Moddable Tech, Inc.
 *
 *   This file is part of the Moddable SDK.
 * 
 *   This work is licensed under the
 *       Creative Commons Attribution 4.0 International License.
 *   To view a copy of this license, visit
 *       <http://creativecommons.org/licenses/by/4.0>.
 *   or send a letter to Creative Commons, PO Box 1866,
 *   Mountain View, CA 94042, USA.
 *
 */

import parseBMF from "commodetto/parseBMF";
import Poco from "commodetto/Poco";
import Resource from "Resource";
import Timer from "timer";

let render = new Poco(screen, { displayListLength: 2048 });

let black = render.makeColor(0, 0, 0);
let white = render.makeColor(255, 255, 255);
let gray = render.makeColor(128, 128, 128);

let battery = new device.peripheral.battery.Default;

let font = parseBMF(new Resource("OpenSans-Semibold-66.bf4"));

let lastPercent = undefined;
Timer.repeat(() => {
	const percent = Math.round(battery.read() * 100);
	if (Math.abs(percent - lastPercent) < 2)
		return;
	lastPercent = percent;
	const percentStr = percent + "%"

	render.begin();
		render.fillRectangle(white, 0, 0, render.width, render.height);

		render.drawText(percentStr, font, black,
			(render.width - render.getTextWidth(percentStr, font)) >> 1,
			-100 + ((render.height - font.height) >> 1));
		
		render.origin(320, 250);
		render.fillRectangle(black, 0, 0, 300, 100);
		render.fillRectangle(white, 10, 10, 280, 80);
		render.fillRectangle(gray, 10, 10, 280 * (percent / 100), 80);
		render.fillRectangle(black, 300, 30, 10, 40);
		render.origin();
	render.end();
}, 200, 0);

new device.peripheral.button.A({
	onPush() {
		if (this.pressed) {
			let t = black;
			black = white;
			white = t;
			lastPercent = undefined;
		}
	}
})

manifest.json

{
	"include": [
		"$(MODDABLE)/examples/manifest_base.json",
		"$(MODDABLE)/examples/manifest_commodetto.json"
	],
	"modules": {
		"*": "./main"
	},
	"resources": {
		"*-mask": [
			{
				"source": "$(MODDABLE)/tools/xsbug/fonts/OpenSans-Semibold",
				"size": 66
			}
		]
	}
}