ASCII to Binary and Binary to ASCII Utility functions in Javascript.

binaryUtil.js

var Util = {
	toBinary: function(input) {
		var result = "";
		for (var i = 0; i < input.length; i++) {
			var bin = input[i].charCodeAt().toString(2);
			result += Array(8 - bin.length + 1).join("0") + bin;
		} 
		return result;
	},

	toAscii: function(input) {
		var result = "";
		var arr = input.match(/.{1,8}/g);
		for (var i = 0; i < arr.length; i++) {
			result += String.fromCharCode(parseInt(arr[i], 2).toString(10));
		}
		return result;
	}
}

I did modified a bit your toAscii() function:
function toAscii(str) { return str.split(' ').map(i => String.fromCharCode(parseInt(i, 2)).toString(10)).join(''); }
in ES6 it looks more nice:
const toAscii= (str) => str.split(' ').map(i => String.fromCharCode(parseInt(i, 2)).toString(10)).join('');