The Meeting Light

AR/VR developer and Full-stack web dev.

December 27, 2015

3dprinter, arduino, blender, electronics, leds

The Meeting Light

My work schedule can get pretty crazy! Really crazy… I thought it might be cool to come up with a way to communicate to that to folks I work with.

I built a little wifi connected RGB LED that will display whether I’m busy, free or about to be busy inside of a 3d printed case. I’ve got all of the 3d files and code here available for download.

3d files

The construction was in two parts, the 3d Files were sent to Shapeways and printed with a SLS process. (They call it ‘strong and flexible’). The topper (transparent shark piece) was ‘clear detail’. Both the case and the topper aren’t particularly well suited to a home 3d printer because of hard drop offs on the case and the topper is very small with fine detail.

STL Files

Exploded Meeting Light Parts
Shark Top
Enclosure

Color:

Render:

Capture:

Download STL

Build Gallery

The wooden base was a pre-cut railing piece from home depot that I drilled holes for the case pegs to push into. I used a lazy method of putting a little paint from a paint pen on the bottom of the pegs, pushed it against the wood for a close approximation of where to drill. This method isn’t precise but in this case it worked well because the slightly imprecise hole placement put a little lateral pressure on the pegs and friction helps keep the case on the wood.

: Instead of being exact, I lazily used a paint pen to mark the pegs on the 3d printed model, then pressed it on to the wood. Then drilled where the marks were. The result was ‘good enough’.

: Here’s the finish I used.

: The wooden base, coated in wood finish, drying.

: The Spark core fitted into the model.

: Shark topper, translucent to allow LED light through.

: It Verks!

Photon Code

The brains behind the LED is a photon, wifi connected microcontroller. The code is pretty simple, it’s basically waiting for an rgb hex value from the Particle API. When it sees it, it parses it out and sets the three PWM channels appropriately. This is mostly from a quick example I found somewhere on the web.

#include <math .h> // only for round();
#define MAX_PARAMS 3 // 3 color channels

String firstArgs = "15,221,222";            // for testing, ints only
String secondArgs = "120.0,121.7,222.9";    // for testing, floats

int led[] = {A4,A5,A6};  // You'll need to wire the RGB-LED:
int onBoardLED = D7; // This one is the built-in tiny one to the right of the USB jack
int sensorReading = 0;
const int knockSensor = A7; // the piezo is connected to analog pin 0
const int threshold = 2080;  // threshold value to decide when the detected sound is a knock or not


void setup() {
  
  /*
  pinMode(A1, OUTPUT);
  pinMode(A2, OUTPUT); 
  pinMode(A3, OUTPUT);
  pinMode(A4, OUTPUT);
  pinMode(A5, OUTPUT);
  pinMode(A6, OUTPUT);
  pinMode(A7, OUTPUT);
  */
  
     for(int i=0;i<max_params ;i++)// 3 color channels; RGB
      {
         pinMode(led[i], OUTPUT);
      }
  pinMode(onBoardLED, OUTPUT);

    Spark.function("changeColor", changeColorFunction);
}

// This routine gets called repeatedly, like once every 5-15 milliseconds.
// Spark firmware interleaves background CPU activity associated with WiFi + Cloud activity with your code. 
// Make sure none of your code delays or blocks for too long (like more than 5 seconds), or weird things can happen.
void loop() {
}

int changeColorFunction(String args)
{
    int length = args.length();
    char separator = ',';

   double allValues[MAX_PARAMS]; // Here 3: there will be 3 values for rgb
   int allValuesCount = 0;
   int from = 0;
   
   for(int i=0;i<=length;i++)// parse all parts of args between the separators
   {
       if(args.charAt(i)==separator || i == length)
       {
         String substring = args.substring(from, i);
         int bufSize = 1+ substring.length();

         char buffer[bufSize];
         substring.toCharArray(buffer, bufSize);
         double value = atof(buffer);
         
         bool isNumber = true;
         
         if(0.0 == value)    // there maybe not a number 
            {
                        int inChar = args.charAt(from);
                         if (isDigit(inChar)) {
                           // we have a string
                           isNumber = false;
                         }

            }
            if(isNumber)
            {
              *(allValues + allValuesCount)=value;
              allValuesCount++;
            }
            // what else could be done?

         if(i < length)    // next substring beyond separator
              from = i+1;
       }
   }
   // limit the color vaues to 3 , red, green and blue
   allValuesCount = (allValuesCount > MAX_PARAMS) ? MAX_PARAMS : allValuesCount;
   for(int i=0; i<allvaluescount ; i++)
       {
         double doubleValue = *(allValues +i);
         int value =  round(doubleValue);
         // manually clamp the value to 0-255
         value = (value < 0) ? 0: value;
         value = (value > 255) ?  255: value;
         // apply the value on the LED
        analogWrite(led[i], value) ;
        //Spark.publish(String(value));
       }

   /*
   for(int i=0;i&lt;30;i++)// just blink and wait
    {
       digitalWrite(onBoardLED, HIGH);
       delay(100);               // Wait for 100mS = 1/10 second
       digitalWrite(onBoardLED, LOW); 
       delay(100);               // Wait for 1/10 second in off mode
    }
    */
  return 1;
}
</allvaluescount></max_params></math>

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#include <math .h> // only for round();

#define MAX_PARAMS 3 // 3 color channels

String firstArgs = "15,221,222"; // for testing, ints only

String secondArgs = "120.0,121.7,222.9"; // for testing, floats

int led[] = {A4,A5,A6}; // You'll need to wire the RGB-LED:

int onBoardLED = D7; // This one is the built-in tiny one to the right of the USB jack

int sensorReading = 0;

const int knockSensor = A7; // the piezo is connected to analog pin 0

const int threshold = 2080; // threshold value to decide when the detected sound is a knock or not

void setup() {

pinMode(A1, OUTPUT);

pinMode(A2, OUTPUT);

pinMode(A3, OUTPUT);

pinMode(A4, OUTPUT);

pinMode(A5, OUTPUT);

pinMode(A6, OUTPUT);

pinMode(A7, OUTPUT);

for(int i=0;i<max_params ;i++)// 3 color channels; RGB

{

pinMode(led[i], OUTPUT);

}

pinMode(onBoardLED, OUTPUT);

Spark.function("changeColor", changeColorFunction);

}

// This routine gets called repeatedly, like once every 5-15 milliseconds.

// Spark firmware interleaves background CPU activity associated with WiFi + Cloud activity with your code.

// Make sure none of your code delays or blocks for too long (like more than 5 seconds), or weird things can happen.

void loop() {

}

int changeColorFunction(String args)

{

int length = args.length();

char separator = ',';

double allValues[MAX_PARAMS]; // Here 3: there will be 3 values for rgb

int allValuesCount = 0;

int from = 0;

for(int i=0;i<=length;i++)// parse all parts of args between the separators

{

if(args.charAt(i)==separator || i == length)

{

String substring = args.substring(from, i);

int bufSize = 1+ substring.length();

char buffer[bufSize];

substring.toCharArray(buffer, bufSize);

double value = atof(buffer);

bool isNumber = true;

if(0.0 == value) // there maybe not a number

{

int inChar = args.charAt(from);

if (isDigit(inChar)) {

// we have a string

isNumber = false;

}

if(isNumber)

{

*(allValues + allValuesCount)=value;

allValuesCount++;

}

// what else could be done?

if(i < length) // next substring beyond separator

from = i+1;

}

// limit the color vaues to 3 , red, green and blue

allValuesCount = (allValuesCount > MAX_PARAMS) ? MAX_PARAMS : allValuesCount;

for(int i=0; i<allvaluescount ; i++)

{

double doubleValue = *(allValues +i);

int value = round(doubleValue);

// manually clamp the value to 0-255

value = (value < 0) ? 0: value;

value = (value > 255) ? 255: value;

// apply the value on the LED

analogWrite(led[i], value) ;

//Spark.publish(String(value));

}

for(int i=0;i<30;i++)// just blink and wait

{

digitalWrite(onBoardLED, HIGH);

delay(100); // Wait for 100mS = 1/10 second

digitalWrite(onBoardLED, LOW);

delay(100); // Wait for 1/10 second in off mode

}

return 1;

}

</allvaluescount></max_params></math>

Color Server

On the server side, I put together a small nodeJS Script that handles colors with an API. Given a server address, it can constantly check for a color from that URL. Or it can accept arbitrary colors through GET requests.

It’s not quite fleshed out here but I thought a fun way to extend this script would be a robust way of keeping track of ‘color devices’, what their current color is, an API to set a new one and an ‘input’ source that would affect it’s color automatically.

var http = require("http");
var request = require('request');
var Router = require('routes');
var router = Router();
var url = require('url')

var handle = null;
var current_color = null;

handle = setInterval(checkColor, 10000);
router.addRoute('/', handleHome);
router.addRoute('/color/:red/:green/:blue/:time', handleColor);
router.addRoute('/*', handle404);


http.createServer(function (req, res) {
        var path = url.parse(req.url).pathname;
        var match = router.match(path);
        match.fn(req, res, match);
}).listen(12415)

function handleHome(req, res, match) {
        fs = require('fs')
        fs.readFile('~/webapps/rgb/index.html', 'utf8', function (err,data) {
        if (err) {
                return console.log(err);
        }
                res.statusCode = 200;
                res.write(data);
                res.end();
        });
}

function handle404(req, res, match) {
        res.statusCode = 404;
        res.write("404, page not found");
        res.end();
}

function handleColor(req, res, match) {
        clearInterval(handle);
        res.statusCode = 200;
        res.end();

        current_color = null;
        console.log(match);
        setColor(match.params.red, match.params.green, match.params.blue);
        handle = setInterval(checkColor, match.params.time * 1000);
}

function setColor(r,g,b) {
        console.log("set the color!" + r + "," + g + "," + b);
        request.post('https://api.spark.io/v1/devices/YOUR_DEVICE_ID/changeColor',
            { form: { "access_token": 'YOUR_ACCESS_TOKEN', "args": r + "," + g + "," + b } },
            function (error, response, body) {
                if (!error) { // && response.statusCode == 200) {
                    console.log(body)
                }
            }
        );
}

function checkColor() {
        request('BUSY_URL_HERE', function (error, response, body) {
                if (!error && response.statusCode == 200) {
                        if(current_color != body) {
                                console.log(body) // Show the HTML for the Google homepage.
                                switch(body) {
                                        case "yes":
                                                setColor(255,1,1);
                                                break;
                                        case "no":
                                                setColor(1,255,1);
                                                break;
                                        case "almost":
                                                setColor(255,255,1);
                                                break;
                                }
                                current_color = body;
                        } else {
                                console.log("already set this color");
                        }
                }
        });
}

var http = require("http");

var request = require('request');

var Router = require('routes');

var router = Router();

var url = require('url')

var handle = null;

var current_color = null;

handle = setInterval(checkColor, 10000);

router.addRoute('/', handleHome);

router.addRoute('/color/:red/:green/:blue/:time', handleColor);

router.addRoute('/*', handle404);

http.createServer(function (req, res) {

var path = url.parse(req.url).pathname;

var match = router.match(path);

match.fn(req, res, match);

}).listen(12415)

function handleHome(req, res, match) {

fs = require('fs')

fs.readFile('~/webapps/rgb/index.html', 'utf8', function (err,data) {

if (err) {

return console.log(err);

}

res.statusCode = 200;

res.write(data);

res.end();

});

}

function handle404(req, res, match) {

res.statusCode = 404;

res.write("404, page not found");

res.end();

}

function handleColor(req, res, match) {

clearInterval(handle);

res.statusCode = 200;

res.end();

current_color = null;

console.log(match);

setColor(match.params.red, match.params.green, match.params.blue);

handle = setInterval(checkColor, match.params.time * 1000);

}

function setColor(r,g,b) {

console.log("set the color!" + r + "," + g + "," + b);

request.post('https://api.spark.io/v1/devices/YOUR_DEVICE_ID/changeColor',

{ form: { "access_token": 'YOUR_ACCESS_TOKEN', "args": r + "," + g + "," + b } },

function (error, response, body) {

if (!error) { // && response.statusCode == 200) {

console.log(body)

}

);

}

function checkColor() {

request('BUSY_URL_HERE', function (error, response, body) {

if (!error && response.statusCode == 200) {

if(current_color != body) {

console.log(body) // Show the HTML for the Google homepage.

switch(body) {

case "yes":

setColor(255,1,1);

break;

case "no":

setColor(1,255,1);

break;

case "almost":

setColor(255,255,1);

break;

}

current_color = body;

} else {

console.log("already set this color");

}

});

}

Outlook Calendar (Busy/Free) Parser

This server side php file will look at a local .VFB file, and parse it out to figure out, am I busy, free or about to be busy (15 minutes or less from being busy) and returns a JSONP file. Pretty simple, the color server will look for this file at it’s URL and use it to determine color!

Basically, have a look at this link about how to publish your free/busy schedule to an FTP location. Then, put this php script somewhere that can see the file locally.

< ?php

$busyonly = $_REQUEST['busyonly'];

// Output one line until end-of-file
$myfile = fopen("tom.vfb", "r") or die("Unable to open file!");

$busy = false;
date_default_timezone_set('America/New_York');
$now = date(time());
$busy = "no";

$json = 'jsonCallback({"events": [';

$myfile = fopen("tom.vfb", "r") or die("Unable to open file!");
while(!feof($myfile)) {
	$line = fgets($myfile);
	if( startswith($line, "FREEBUSY:") ){
		$start = strtotime(substr($line, 9, 16));
		$startminus = $start - 900;
		$end =   strtotime(substr($line, 26, 16));
		if($now > $startminus && $now < $end) 
		{
			$busy = "almost";
		}
		//date('l dS \o\f F Y h:i:s A', $start)
	}
}
fclose($myfile);


$myfile = fopen("tom.vfb", "r") or die("Unable to open file!");
while(!feof($myfile)) {
	$line = fgets($myfile);
	if( startswith($line, "FREEBUSY:") ){
		$start = strtotime(substr($line, 9, 16));
		$end =   strtotime(substr($line, 26, 16));
		if($now > $start && $now < $end) 
		{
			$busy = "yes";
		}
		//date('l dS \o\f F Y h:i:s A', $start)
		$json .= '{"start":"' . date('Y-m-d H:i:s', $start) . '","end":"' . date('Y-m-d H:i:s', $end) . '"},';
	}
}

fclose($myfile);

$json = rtrim($json, ",");
//$busystring = ($busy) ? 'true' : 'false';
$busystring = $busy;


$json .= '],"busy": "' . $busystring . '"});';


if($busyonly == "true") {
	echo $busystring;
} else {
	header('Content-Type: application/javascript');
	echo $json;
}


function startsWith($haystack, $needle)
{
	$length = strlen($needle);
	return (substr($haystack, 0, $length) === $needle);
}

?>

< ?php

$busyonly = $_REQUEST['busyonly'];

// Output one line until end-of-file

$myfile = fopen("tom.vfb", "r") or die("Unable to open file!");

$busy = false;

date_default_timezone_set('America/New_York');

$now = date(time());

$busy = "no";

$json = 'jsonCallback({"events": [';

$myfile = fopen("tom.vfb", "r") or die("Unable to open file!");

while(!feof($myfile)) {

$line = fgets($myfile);

if( startswith($line, "FREEBUSY:") ){

$start = strtotime(substr($line, 9, 16));

$startminus = $start - 900;

$end = strtotime(substr($line, 26, 16));

if($now > $startminus && $now < $end)

{

$busy = "almost";

}

//date('l dS \o\f F Y h:i:s A', $start)

}

fclose($myfile);

$myfile = fopen("tom.vfb", "r") or die("Unable to open file!");

while(!feof($myfile)) {

$line = fgets($myfile);

if( startswith($line, "FREEBUSY:") ){

$start = strtotime(substr($line, 9, 16));

$end = strtotime(substr($line, 26, 16));

if($now > $start && $now < $end)

{

$busy = "yes";

}

//date('l dS \o\f F Y h:i:s A', $start)

$json .= '{"start":"' . date('Y-m-d H:i:s', $start) . '","end":"' . date('Y-m-d H:i:s', $end) . '"},';

}

fclose($myfile);

$json = rtrim($json, ",");

//$busystring = ($busy) ? 'true' : 'false';

$busystring = $busy;

$json .= '],"busy": "' . $busystring . '"});';

if($busyonly == "true") {

echo $busystring;

} else {

header('Content-Type: application/javascript');

echo $json;

}

function startsWith($haystack, $needle)

{

$length = strlen($needle);

return (substr($haystack, 0, $length) === $needle);

}

Hey thanks for reading this far! Maybe you'll be interested in more of my projects? Check out my homepage :)