pianosnake’s gists

pianosnake / spark-core-listener.html

Last active August 29, 2015 14:06

Setup Server Sent Events (SSE) from Spark Core. Connect potentiometer to A0 and average out the readings for sse-potentiometer.ino. Connect switch to D2 for sse-switch.ino. Clients are notified when values change.

	<html>

	<head>
	<style>
	body{
	font-family: sans-serif;
	}
	#spark{
	font-size: 90px;
	font-weight: bold;

pianosnake / hasOwnProperties.js

Created June 24, 2016 15:37

Recursive implementation of JavaScript hasOwnProperty().

	//example:
	//var nestedObj = {planet: {earth: {'@continent': 'africa'}}};
	//hasOwnProperties(nestedObj, 'planet.earth.@continent') //returns true
	//hasOwnProperties(nestedObj, 'planet.earth.@continent', 'africa') //returns true
	//hasOwnProperties(nestedObj, 'planet.earth.unicorns') //returns false

	hasOwnProperties: function(target, path, value){
	if (typeof target !== 'object' \|\| target === null) { return false; }

	var parts = path.split('.');

pianosnake / arduino-hammond-pedals.ino

Last active July 23, 2016 16:39

This enables polyphonic MIDI output from a Hammond M-3 12 pedal console through an Arduino Nano. The original wiring has all the switches connected in series. Keep the black wire coming to each key, but cut the exposed wires connecting the keys to each other. Lastly connect the ground from each key together to the main ground.

	#include <MIDI.h>

	const byte tones = 12;
	const byte midiStart = 36;
	const byte onDebounce = 10;
	const byte offDebounce = 60;
	const byte pedalPins[] = {2, 3, 4, 5, 6, 7, 8, A0, A1, 11, 12, A2};

	byte note;
	byte playing[tones];

pianosnake / remove-query-param.js

Created July 22, 2016 21:15

Remove a query param from URL

-function removeQueryParam(url, param){
-  var paramInMiddle = new RegExp('&' + param + '=\\w*');    //  &param=blah
-  var paramInFront  = new RegExp('\\?' + param + '=\\w*&'); //  ?param=blah&
-  var paramSolo     = new RegExp('\\?' + param + '=\\w*');  //  ?param=blah
-  return url
-    .replace(paramInMiddle, '')
-    .replace(paramInFront, '?')
-    .replace(paramSolo, '');
-}

pianosnake / jasmine-time-reporter.js

Last active May 31, 2017 21:35

Custom reporter for Jasmine to display the slowest tests in a Node project

	'use strict';

	//This reporter shows the slowest specs at the end of a test run

	const chalk = require('chalk');
	const specs = {};

	function sortedSpecs(){
	return Object.keys(specs)
	.map(key => specs[key]) //convert object to array

pianosnake / gist:af8b04f9db7987f55832ca2394b74ae0

Created June 2, 2017 22:54

Find out who wrote the bad JavaScript!! Use `git blame` on each line output by ESLINT

eslint "**/**.js" -f unix | perl -n -l -e '/(.*\.js):(\d*):/ && print "$1 $2"' | xargs -n 2 sh -c 'git blame $0 -L$1,$1'

pianosnake / throttle-promises.js

Created August 22, 2017 21:13

Promise throttling using a generator

	function throttlePromises(elements, asyncForEach, groupSize){
	return new Promise(function(resolve, reject){
	//create a generator object that 'yields' for every group
	const genObj = function* gen(){
	while(elements.length > 0){
	yield Promise.all(elements.splice(0, groupSize).map(asyncForEach))
	.then(() => genObj.next());
	}
	return resolve(true);
	}();

pianosnake / insistent request using generators.js

Last active September 21, 2017 19:47

retry a Request repeatedly until it succeeds or the try limit is reached

	function insistentRequest(request, tryLimit){
	if(!tryLimit) return Promise.reject('tryLimit must be above 0');
	let tries = 0;

	return new Promise(function(resolve, reject){
	//create a generator object that repeatedly 'yields' the same promise until it succeeds or the try limit is reached
	const genObj = function* gen(){
	while(1){
	yield request()
	.then(resolve)

pianosnake / cardinalDirection.js

Last active April 18, 2018 16:00

Convert bearing (0-360 degrees) to cardinal direction (N, NW, etc...)

	//divide 360 into 16 equal slices
	const degrees = (new Array(16)).fill(null).map((x, i) => 360/16 * i + 11.25);
	const directions = ['N', 'NNE', 'NE', 'ENE', 'E', 'ESE', 'SE', 'SSE', 'S', 'SSW', 'SW', 'WSW', 'W', 'WNW', 'NW', 'NNW'];

	function cardinalDirection(bearing) {
	for (let i = 0, l = degrees.length; i < l; i++) {
	if (bearing < degrees[i]) return directions[i];
	if (i == l - 1) return directions[0];
	}
	}

pianosnake / bounding-box-area.js

Last active July 16, 2018 22:38

Computes the area of a geographic bounding box assuming spherical Earth

	// adapted from http://mathforum.org/library/drmath/view/63767.html

	const r = 6371.0072; //earth radius in KM

	function toRadians(degrees) {
	return degrees * Math.PI / 180;
	};

	function computeArea(bbox){
	const [minLng, minLat, maxLng, maxLat] = bbox;