Aron Steg blindman2k

This was the result of a fun hackathon project at Electric Imp. I turned a NeoPixel ring and an Impeeduino (Arduino and Imp hybrid) into a basic audio spectrum display. The video can be seen on YouTube.

The arduino code is responsible for reading audio data from the microphone, running a fast fourier transform on the data captured to product a spectrum and then handing it off to the Imp device code via UART.
The agent code is responsible only for assisting with the programming of new Arduino code and could be done with the Arduino IDE directly.
The device code is responsible for reading the spectrum data and displaying the animation on the NeoPixels.

This code is provided without warantee or support because I can't remember much about it.

Securing Electric Imp agents acting as API providers

There are a myriad of different ways to secure requests to agent URLs. By default, all requests have three simple security features:

the unique URL for each device is randomly generated during the BlinkUp process;
the commands required to activate the agent are unknown to anyone but the developers; and
all requests to https://agent.electricimp.com are SSL encrypted which prevents anyone from sniffing the contents of any request.

For many applications, this encryption plus obfuscation is sufficient security, especially if the requests to the agent are coming from a server or a controlled application. If further security/obfuscation is required we propose a few simple and common methods here. These methods also provide a bonus feature that, if the security is compromised at any point in the future, the parameters can be easily changed to reassert the security.

	/* 9 Degrees of Freedom Sensor Tail Firmware
	* Uses LSM9DS0 IMU from ST
	* http://www.adafruit.com/datasheets/LSM9DS0.pdf
	*/

	const XM_ADDR = 0x3C; // 8-bit I2C Student Address for Accel / Magnetometer
	const G_ADDR = 0xD4; // 8-bit I2C Student Address for Angular Rate Sensor
	const READING_INTERVAL = 1; // seconds between readings

	/* CLASS AND GLOBAL FUNCTION DEFINITIONS ------------------------------------ */

	/* Environmental Sensor Tail Firmware
	* Ambient Light Sensor: APDS-9007-020 (http://www.avagotech.com/docs/AV02-0512EN)
	* Air Pressure Sensor: LPS25HTR (http://www.st.com/web/en/resource/technical/document/datasheet/DM00066332.pdf)
	* Humidity/Temp Sensor: SI7020-A10-GMR (http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7020.pdf)
	*/

	const LPS25H_ADDR = 0xB8; // 8-bit I2C Student Address for LPS25HTR
	const SI7020_ADDR = 0x80; // 8-bit I2C Student Address for SI7020
	const ALS_RLOAD = 47000.0; // load resistor value on ALS
	const READING_INTERVAL = 3; // seconds between readings

	//------------------------------------------------------------------------------------------------
	const CALENDAR_URL = "http://devious-dorris.gopagoda.com/meeting_minder";
	const REFRESH_TIME = 60; // Once a minute

	SESSION_TOKEN <- "token" in server.load() ? server.load().token : "";
	// server.log(SESSION_TOKEN);

	function check_calendar(reschedule = true) {
	local headers = {};
	headers["X-GCal-Session-Token"] <- SESSION_TOKEN;



	// -----------------------------------------------------------------------------
	const html = @"
	<!DOCTYPE html>
	<html lang='en'>
	<head>
	<meta charset='utf-8'>
	<meta http-equiv='X-UA-Compatible' content='IE=edge'>
	<meta name='viewport' content='width=device-width, initial-scale=1'>

	function number_format(num, decimals=null, separator=",") {
	// Fix the decimals
	if (decimals == null) {
	if (typeof num == "string") decimals = 0;
	else if (typeof num == "integer") decimals = 0;
	else if (typeof num == "float") decimals = 2;
	else return num;
	}
	// Check we have a number or convert to one if required
	if (typeof num == "string") {

	// -----------------------------------------------------------------------------
	class HTTPPlus {

	_http = null;

	// .........................................................................
	// Keep a copy of the original http object for internal use
	constructor() {
	_http = http;
	}

	HTTPRetry.get("http://icanhazip.com").sendasync(function(res) {
	if (res.statuscode == 200) {
	server.log(res.body);
	} else {
	server.log("Error: " + res.statuscode);
	}
	});

	// ------------------------------------------------------------------------
	// Takes a string, renders it and sends it to the device for display
	text <- null;
	function displayText(_text) {
	device.send("text", _text);
	text = _text;
	}


	// ------------------------------------------------------------------------