How's the world feeling right now? This box tells you.
Powered by: an Arduino, a WiFly wireless module, an RGB LED, Twitter.com and a 9v battery.
I’m a news junkie. I want to know everything that is going on in the world as soon as it happens. I want to wake up and know immediately if something big has happened overnight.
However, I’m an extraordinarily busy man; I don’t have time to read news feeds; reading that headline that I already knew about or don’t care about is time that I’m never getting back!
No. What I need is some way to be constantly in touch with the world's events as they unfold, alerted when something big happens, and to be made aware of it all faster than awareness itself!
...A way to get a glimpse of the collective human consciousness as an extension of my own. Something that I don't have to continually check or poll, but instead, like a part of my body, it will tell me when it's feeling pain or generally in need of my attention ...leaving me time to get on with other things.
And so, I present: The World Mood in a Box!
The Arduino connects directly to any wireless network via the WiFly module, continually searches Twitter for tweets with emotional content, collates the tweets for each emotion, does some math, and then fades the color of the LED to reflect the current World Mood; Red for Anger, Yellow for Happy, Pink for Love, White for Fear, Green for Envy, Orange for Surprise, and Blue for Sadness.
If an unexpectedly high number of tweets of a particular emotion are found, then the LED will flash to alert us to the possibility of a world event that has caused this unusually strong emotional reaction.
For example, a world disaster and it may flash Blue or Red (sadness or anger), if the strong favourite loses a big football game it may fade to Orange (surprise), …and If it flashes White, the collective human mind is feeling extreme fear, and it's probably best to go hide in a cupboard and sit it out, waiting for sunnier skies and a return to Yellow or Pink. ...OK, I'm not that busy.
Step 1: How it works
An Arduino connects directly (no computer
required!) to any wireless network via the WiFly module, repeatedly
searches Twitter for tweets with emotional content (aka sentiment
extraction or tapping into the moodosphere), collates the tweets for
each emotion, analyzes the data, and fades the color of an LED to
reflect the current World Mood:
- Red for Anger
- Yellow for Happy
- Pink for Love
- White for Fear
- Green for Envy
- Orange for Surprise
- Blue for Sadness
- "wow"
- "can't believe"
- "unbelievable"
- "O_o"
Example signals:
- A world disaster and it may flash Blue or Red indicating it best to check a news site to see why everyone is so sad and/or angry.
- If the strong favourite loses a big football game, it may flash Orange to express the surprise at this unlikely event.
- If there is a heat wave in London it might turn Yellow to reflect how much happier people now are.
- If it flashes White, the collective human consciousness is feeling extreme fear and something terrifyingly bad is probably about to happen. Time to hide and/or panic.
- You could put it on your desk to get an early warning of something big happening somewhere in the world
- A literal 'mood light' at a party or a game whereby you guess what colour it will change to next and for what reason
- A world mood barometer perhaps next to your bed to decide if it is best to hit snooze until it's less angry outside
- A gauge of public sentiment to help you decide when to sell all your stocks and shares, and head to the hills.
- In a foyer or waiting area or other public space for people to look at and contemplate.
- Set it to connect to any wireless network and carry it around in the streets, stopping strangers to explain to them that you have managed to capture the world's mood and have it locked in this here box.
Step 2: All you need is...
I
ordered most of the electronics from Sparkfun, and picked up the rest
from the local Radioshack. The acrylic I got from a local plastic
shop(!) - they cut it and drilled a hole free of charge.
Materials
The Arduino development tools can be downloaded from here:
www.arduino.cc/en/Main/Software
and Arduino tutorials start here:
http://arduino.cc/en/Guide/HomePage
Arduino / WiFly:
arduino.cc/en/Reference/HomePage
http://www.arduino.cc/en/Tutorial/SPIEEPROM
http://www.lammertbies.nl/comm/info/serial-uart.html
http://www.tinyclr.com/downloads/Shield/FEZ_Shields_WiFly.cs
http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=158
http://www.sparkfun.com/datasheets/Components/SMD/sc16is750.pdf
http://www.sparkfun.com/datasheets/Wireless/WiFi/WiFlyGSX-um.pdf
http://www.sparkfun.com/datasheets/Wireless/WiFi/rn-131G-ds.pdf
http://www.societyofrobots.com/microcontroller_uart.shtml
Related:
nlp.stanford.edu/courses/cs224n/2009/fp/22.pdf
www.webservius.com/corp/docs/tweetfeel_sentiment.htm
i8news.uterm.org/mood/twitter-mood-reader/
community.openamplify.com/content/docs.aspx/
www.instructables.com/id/The-Twittering-Office-Chair/
http://www.tweetfeel.com
Materials
- Arduino Duemilanove
- Wifly Shield www.sparkfun.com/commerce/product_info.php
- Breakaway headers www.sparkfun.com/commerce/product_info.php
- 9v battery
- 9v to Barrel Jack Adapter
- 5mm RGB LED
- 3x resistors (2x100 ohm,1x180 ohm)
- Wire
- Small printed circuit board
- USB Cable A to B to connect Arduino to computer
- Rosin-core solder
- Source code
- 1 x (5" x 5" x 0.25") - the top
- 4 * (4.75" x 4.75" x 0.25") - the 4 walls
- 1 x (4.5" x 4.5" x 0.25") - the base
- 1 x (4.5" x 4.5" x 0.125") - the mirror with a 6mm hole drilled in the middle
- 4 x (4.25 x 1" x 0.25") - the 4 inside walls
- Acrylic solvent cement
- Sand paper (to help diffuse the light)
- Soldering iron
- A computer
- Arduino development environment
- A wireless network (802.11b/g)
- Pliers
- Wire stripper
The Arduino development tools can be downloaded from here:
www.arduino.cc/en/Main/Software
and Arduino tutorials start here:
http://arduino.cc/en/Guide/HomePage
Arduino / WiFly:
arduino.cc/en/Reference/HomePage
http://www.arduino.cc/en/Tutorial/SPIEEPROM
http://www.lammertbies.nl/comm/info/serial-uart.html
http://www.tinyclr.com/downloads/Shield/FEZ_Shields_WiFly.cs
http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=158
http://www.sparkfun.com/datasheets/Components/SMD/sc16is750.pdf
http://www.sparkfun.com/datasheets/Wireless/WiFi/WiFlyGSX-um.pdf
http://www.sparkfun.com/datasheets/Wireless/WiFi/rn-131G-ds.pdf
http://www.societyofrobots.com/microcontroller_uart.shtml
Related:
nlp.stanford.edu/courses/cs224n/2009/fp/22.pdf
www.webservius.com/corp/docs/tweetfeel_sentiment.htm
i8news.uterm.org/mood/twitter-mood-reader/
community.openamplify.com/content/docs.aspx/
www.instructables.com/id/The-Twittering-Office-Chair/
http://www.tweetfeel.com
Step 3: Connect the Arduino and WiFly to a computer
Sparkfun have a decent tutorial on how to do this:
www.sparkfun.com/commerce/tutorial_info.php
Firstly, the Wifly breakout board needs to be stacked on top of the arduino and the RX, TX, Vin, Gnd, pin 10, pin 11, pin 12 and pin 13 needed to be connected. I used breakaway headers and soldered the required pins.
Connect to a computer using an A to B USB cable.
Download the Arduino software from here:
arduino.cc/en/Main/Software
Check that you can compile and upload a sample program by following the instructions here:
(remember to set the board and COM ports correctly)
arduino.cc/en/Guide/HomePage
www.sparkfun.com/commerce/tutorial_info.php
Firstly, the Wifly breakout board needs to be stacked on top of the arduino and the RX, TX, Vin, Gnd, pin 10, pin 11, pin 12 and pin 13 needed to be connected. I used breakaway headers and soldered the required pins.
Connect to a computer using an A to B USB cable.
Download the Arduino software from here:
arduino.cc/en/Main/Software
Check that you can compile and upload a sample program by following the instructions here:
(remember to set the board and COM ports correctly)
arduino.cc/en/Guide/HomePage
Step 4: Connecting the LED
Only some pins provide 8-bit PWM (Pulse-width modulation)
This gives 256 steps of control from full off (0) to full on (255) for each of the Red, Green and Blue channels of the LED.
This gives 256 steps of control from full off (0) to full on (255) for each of the Red, Green and Blue channels of the LED.
PWM pins on the Arduino are 3,5,6,9,10,11. (see www.arduino.cc/en/Main/ArduinoBoardDuemilanove)
I used 3, 5 and 6.
Note: The pictures illustrate using the same resistor for each colour channel, but I should have used the resistance levels in the data sheet:
180 Ohm for Red
100 Ohm for Green
100 Ohm for Blue
Also note, I covered the back with insulating tape to stop any shorts when putting it all into the box.
Also, from the datasheet, "the Sensor inputs SENS0-7 are extremely sensitive to over voltage. Under no conditions should these pins be driven above 1.2VDC. Placing any voltage above
this will permanently damage the radio module and render it useless."
wiring.org.co/learning/basics/rgbled.html
www.sparkfun.com/datasheets/Components/YSL-R596CR3G4B5C-C10.pdf
Step 5: Choosing good search terms
Twitter allows you to search for recent tweets that contain particular words or phrases.
You can search for tweets that contain any of a list of phrases by using the "+OR+" conjunction.
For example, here is a search request that might find tweets that express Fear:
GET /search.json?q="i'm+so+scared"+OR+"i'm+really+scared"+OR+"i'm+terrified"+OR+"i'm+really+afraid"+OR+"so+scared+i"&rpp=30&result_type=recent
I spent a long time finding good search phrases.
The search phrases needed to produce tweets that:
- very often express the desired emotion.
- very rarely express the opposite emotion or no emotion.
Many search phrases that I thought would work, turned out to not work that well when I searched with them.
Smileys have been used with some success to extract whether the sentence is positive or negative, but I didn't find them useful for extracting anything more.
The trouble with smileys is that a smile can mean so many things ;D
It is often used, it seems, as a kind of qualifier for the whole sentence; since people have to compress their thoughts into 140 characters, the meaning can become ambiguous.
The smiley often then acts as a qualifier that:
- 'this is a friendly comment'
- 'don't take this the wrong way'
- 'i am saying hello/goodbye with a smile'
- 'this is almost a joke'
- 'I know I'm being cheeky'
- 'I don't really mean this'
"so scared" or "really scared" is better than just "scared" which returns bad results: for example, "not scared".
Phrases in the first person seemed to produce better results.
Some search phrases give tweets that suggest the author feels the emotion: for example, "i really hate...", often sounds like they really are full of hate or angry, whereas other phrases containing the word "hate" give tweets that do not seem to express much emotion, like "why do you hate..."
Hyperbole is your best friend, ever:
Using phrases with hyperbole produced good results. Tweets with "I'm terrified" or "I'm petrified" in them were generally more fearful sounding than "I'm scared"
Regardless, the approach is still naive, but statistically, from my tests, it does seem to work well.
While testing the code, I did at one point get the horribly ominous "Flashing White" that signifies the world is feeling intense fear, but since I was still testing it all, I did not hide under the table straight away, but instead, threw caution to the winds, and went on to Twitter to see what people were suddenly so fearful about.
The recent tweets containing the Fear search string (see top of page) were largely relating to a large thunderstorm that had just started somewhere near Florida.
If you're interested, here are some of those tweets:
So... it works! ...Well, it needs the numbers tweaking to ignore the world's "tantrums", the short-lived fits of emotional outburst, and be more concerned with larger changes that signify bigger news.
- "Ahhh Thunder I'm so scared of Thunder !!!!! Help some 1"
- "I'm so scared of lightning now. Like I just ran home praying "
- "On our way to Narcosses at @Disney world's Grand Floridian hotel and there's a tropical storm right now. I'm terrified! ..."
- "I'm in my bathroom til the rain stops. I'm terrified of lightning and thunder..."
- "I'm terrified of thunder storms *hides in corner*"
- "I'm terrified of Thunder :("
- "If only I was wit my becky during this thunderstorm cause I'm really scared cause of a bad experience"
Step 6: Download the code
The attached WorldMood.zip contains 4 subdirectories (or "libraries") and the Arduino sketch WorldMood.pde
The four libraries need to be copied into the Arduino library directory and then they can be imported as shown.
WorldMood/WorldMood.pde (see below) should be opened in the Arduino development environment.
You then need to correct the "[your network]" and "[your network password]" fields. eg.
#define network ("mynetwork")
#define password ("mypassword")
Then the sketch (and libraries) should be compiled and uploaded to the Arduino board.
see arduino.cc/en/Hacking/LibraryTutorial
The next 5 programming steps just give an overview of each of the components and include the most noteworthy parts of the source code...
**** Update ****
If you have a newer board then you may need to change this
struct SPI_UART_cfg SPI_Uart_config = {0x50,0x00,0x03,0x10};
to this:
struct SPI_UART_cfg SPI_Uart_config = {0x60,0x00,0x03,0x10};
See here for more info:
http://forum.sparkfun.com/viewtopic.php?f=13&t=21846&sid=24282242d4256db0c7b7e814d7ca6952&start=15
http://www.sparkfun.com/commerce/product_info.php?products_id=9367
***** End Update ****
The four libraries need to be copied into the Arduino library directory and then they can be imported as shown.
WorldMood/WorldMood.pde (see below) should be opened in the Arduino development environment.
You then need to correct the "[your network]" and "[your network password]" fields. eg.
#define network ("mynetwork")
#define password ("mypassword")
Then the sketch (and libraries) should be compiled and uploaded to the Arduino board.
see arduino.cc/en/Hacking/LibraryTutorial
The next 5 programming steps just give an overview of each of the components and include the most noteworthy parts of the source code...
**** Update ****
If you have a newer board then you may need to change this
struct SPI_UART_cfg SPI_Uart_config = {0x50,0x00,0x03,0x10};
to this:
struct SPI_UART_cfg SPI_Uart_config = {0x60,0x00,0x03,0x10};
See here for more info:
http://forum.sparkfun.com/viewtopic.php?f=13&t=21846&sid=24282242d4256db0c7b7e814d7ca6952&start=15
http://www.sparkfun.com/commerce/product_info.php?products_id=9367
***** End Update ****
// LED setup - only some pins provide 8-bit PWM (Pulse-width modulation)
// output with the analogWrite() function.
// http://www.arduino.cc/en/Main/ArduinoBoardDuemilanove
// PWM: 3,5,6,9,10,11
#define redPin (3)
#define greenPin (5)
#define bluePin (6)
// delay in ms between fade updates
// max fade time = 255 * 15 = 3.825s
#define fadeDelay (15)
// Wifi setup
#define network ([your network])
#define password ([your network password])
#define remoteServer ("twitter.com")
const char* moodNames[NUM_MOOD_TYPES] = {
"love",
"joy",
"surprise",
"anger",
"envy",
"sadness",
"fear",
};
const char* moodIntensityNames[NUM_MOOD_INTENSITY] = {
"mild",
"considerable",
"extreme",
};
// the long term ratios between tweets with emotional content
// as discovered by using the below search terms over a period of time.
float tempramentRatios[NUM_MOOD_TYPES] = {
0.13f,
0.15f,
0.20f,
0.14f,
0.16f,
0.12f,
0.10f,
};
// these numbers can be tweaked to get the system to be more or less reactive
// to be more or less susceptible to noise or short term emotional blips, like sport results
// or bigger events, like world disasters
#define emotionSmoothingFactor (0.1f)
#define moodSmoothingFactor (0.05f)
#define moderateMoodThreshold (2.0f)
#define extremeMoodThreshold (4.0f)
// save battery, put the wifly to sleep for this long between searches (in ms)
#define SLEEP_TIME_BETWEEN_SEARCHES (1000 * 5)
// Store search strings in flash (program) memory instead of SRAM.
// http://www.arduino.cc/en/Reference/PROGMEM
// edit TWEETS_PER_PAGE if changing the rpp value
prog_char string_0[] PROGMEM = "GET
/search.json?q=\"i+love+you\"+OR+\"i+love+her\"+OR+\"i+love+him\"+OR+\"all+my+love\"+OR+\"i'm+in+love\"+OR+\"i+really+love\"&rpp=30&result_type=recent";
prog_char string_1[] PROGMEM = "GET
/search.json?q=\"happiest\"+OR+\"so+happy\"+OR+\"so+excited\"+OR+\"i'm+happy\"+OR+\"woot\"+OR+\"w00t\"&rpp=30&result_type=recent";
prog_char string_2[] PROGMEM = "GET /search.json?q=\"wow\"+OR+\"O_o\"+OR+\"can't+believe\"+OR+\"wtf\"+OR+\"unbelievable\"&rpp=30&result_type=recent";
prog_char string_3[] PROGMEM = "GET
/search.json?q=\"i+hate\"+OR+\"really+angry\"+OR+\"i+am+mad\"+OR+\"really+hate\"+OR+\"so+angry\"&rpp=30&result_type=recent";
prog_char string_4[] PROGMEM = "GET
/search.json?q=\"i+wish+i\"+OR+\"i'm+envious\"+OR+
\"i'm+jealous\"+OR+\"i+want+to+be\"+OR+\"why+can't+i\"+&rpp=30&result_type=recent";
prog_char string_5[] PROGMEM = "GET
/search.json?q=\"i'm+so+sad\"+OR+\"i'm+heartbroken\"+OR+\"i'm+so+upset\"+OR+\"i'm+depressed\"+OR+\"i+can't+stop+crying\"&rpp=30&result_type=recent";
prog_char string_6[] PROGMEM = "GET
/search.json?q=\"i'm+so+scared\"+OR+\"i'm+really+scared\"+OR+\"i'm+terrified\"+OR+\"i'm+really+afraid\"+OR+\"so+scared+i\"&rpp=30&result_type=recent";
// be sure to change this if you edit the rpp value above
#define TWEETS_PER_PAGE (30)
PROGMEM const char *searchStrings[] =
{
string_0,
string_1,
string_2,
string_3,
string_4,
string_5,
string_6,
};
void setup()
{
Serial.begin(9600);
delay(100);
}
void loop()
{
// create and initialise the subsystems
WiFly wifly(network, password, SLEEP_TIME_BETWEEN_SEARCHES, Serial);
WorldMood worldMood(Serial, emotionSmoothingFactor, moodSmoothingFactor, moderateMoodThreshold, extremeMoodThreshold, tempramentRatios);
LED led(Serial, redPin, greenPin, bluePin, fadeDelay);
TwitterParser twitterSearchParser(Serial, TWEETS_PER_PAGE);
wifly.Reset();
char searchString[160];
while (true)
{
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
twitterSearchParser.Reset();
// read in new search string to SRAM from flash memory
strcpy_P(searchString, (char*)pgm_read_word(&(searchStrings[i])));
bool ok = false;
int retries = 0;
// some recovery code if the web request fails
while (!ok)
{
ok = wifly.HttpWebRequest(remoteServer, searchString, &twitterSearchParser);
if (!ok)
{
Serial.println("HttpWebRequest failed");
retries++;
if (retries > 3)
{
wifly.Reset();
retries = 0;
}
}
}
float tweetsPerMinute = twitterSearchParser.GetTweetsPerMinute();
// debug code
Serial.println("");
Serial.print(moodNames[i]);
Serial.print(": tweets per min = ");
Serial.println(tweetsPerMinute);
worldMood.RegisterTweets(i, tweetsPerMinute);
}
MOOD_TYPE newMood = worldMood.ComputeCurrentMood();
MOOD_INTENSITY newMoodIntensity = worldMood.ComputeCurrentMoodIntensity();
Serial.print("The Mood of the World is ... ");
Serial.print(moodIntensityNames[(int)newMoodIntensity]);
Serial.print(" ");
Serial.println(moodNames[(int)newMood]);
led.SetColor((int)newMood, (int)newMoodIntensity);
// save the battery
wifly.Sleep();
// wait until it is time for the next update
delay(SLEEP_TIME_BETWEEN_SEARCHES);
Serial.println("");
}
}
WorldMood.zip18 KBStep 7: Programming step 1: SPI UART
The WiFly Shield equips your Arduino with the ability to connect to 802.11b/g wireless networks.
The featured components of the shield are:
The Universal asynchronous receiver/transmitter (or UART) is a type of asynchronous receiver/transmitter, a piece of computer hardware that translates data between parallel and serial forms.
The code below is based on a number of sources, but primarily from this tutorial over at sparkfun:
www.sparkfun.com/commerce/tutorial_info.php
WiFly Wireless Talking SpeakJet Server
The featured components of the shield are:
- a Roving Network's RN-131G wireless module
- SC16IS750 SPI-to-UART chip.
The Universal asynchronous receiver/transmitter (or UART) is a type of asynchronous receiver/transmitter, a piece of computer hardware that translates data between parallel and serial forms.
- The PC communicates over UART with the Arduino through pins RX and TX
- The Arduino communicates over SPI with the SPI-UART chip on the WiFly shield (SC16IS750 SPI-to-UART chip) though pins 10-13 (CS, MOSI, MISO, SCLK respectively)
- The RN-131G wireless module accesses network and send/receive serial data over UART.
The code below is based on a number of sources, but primarily from this tutorial over at sparkfun:
www.sparkfun.com/commerce/tutorial_info.php
WiFly Wireless Talking SpeakJet Server
/* Test if the SPI<->UART bridge has been set up correctly by writing a test
character via SPI and reading it back.
returns true if success
*/
bool WiFly::TestSPI_UART_Bridge()
{
// Perform read/write test to check if SPI<->UART bridge is working
// write a character to the scratchpad register.
WriteByteToRegister(SPR, 0x55);
char data = ReadCharFromWiFly(SPR);
if(data == 0x55)
{
return true;
}
else
{
m_printer->println("Failed to init SPI<->UART chip");
return false;
}
}
/* A series of register writes to initialize the SC16IS750 SPI-UART bridge chip
see http://www.tinyclr.com/downloads/Shield/FEZ_Shields_WiFly.cs
*/
void WiFly::SPI_UART_Init(void)
{
WriteByteToRegister(LCR,0x80); // 0x80 to program baudrate
WriteByteToRegister(DLL,SPI_Uart_config.DivL); //0x50 = 9600 with Xtal = 12.288MHz
WriteByteToRegister(DLM,SPI_Uart_config.DivM);
WriteByteToRegister(LCR, 0xBF); // access EFR register
WriteByteToRegister(EFR, SPI_Uart_config.Flow); // enable enhanced registers
WriteByteToRegister(LCR, SPI_Uart_config.DataFormat); // 8 data bit, 1 stop bit, no parity
WriteByteToRegister(FCR, 0x06); // reset TXFIFO, reset RXFIFO, non FIFO mode
WriteByteToRegister(FCR, 0x01); // enable FIFO mode
}
Step 8: Programming step 2: Connecting to a Wireless Network
Again,
this is largely based on the sparkfun tutorial, but I've removed the
delays with "waits for response". This speeds things up and is easier to
error check.
www.sparkfun.com/commerce/tutorial_info.php
www.sparkfun.com/commerce/tutorial_info.php
/*
Send the correct commands to connect to a wireless network using the parameters used on construction
*/
void WiFly::AutoConnect()
{
delay(DEFAULT_TIME_TO_READY);
FlushRX();
// Enter command mode
EnterCommandMode();
// Reboot to get device into known state
WriteToWiFlyCR("reboot");
WaitUntilReceived("*Reboot*");
WaitUntilReceived("*READY*");
FlushRX();
// Enter command mode
EnterCommandMode();
// turn off auto joining
WriteToWiFlyCR("set wlan join 0");
WaitUntilReceived(AOK, ERR);
// Set authentication level to
WriteToWiFly("set w a ");
WriteToWiFlyCR(auth_level);
WaitUntilReceived(AOK, ERR);
// Set authentication phrase to
WriteToWiFly("set w p ");
WriteToWiFlyCR(m_password);
WaitUntilReceived(AOK, ERR);
// Set localport to
WriteToWiFly("set i l ");
WriteToWiFlyCR(port_listen);
WaitUntilReceived(AOK, ERR);
// Deactivate remote connection automatic message
WriteToWiFlyCR("set comm remote 0");
WaitUntilReceived(AOK, ERR);
// Join wireless network
WriteToWiFly("join ");
WriteToWiFlyCR(m_network);
delay(DEFAULT_TIME_TO_JOIN);
bool ok = WaitUntilReceived("IP=");
delay(DEFAULT_TIME_TO_WAIT);
FlushRX();
if(ok == false)
{
m_printer->print("Failed to associate with '");
m_printer->print(m_network);
m_printer->println("'\n\rRetrying...");
FlushRX();
AutoConnect();
}
else
{
m_printer->println("Associated!");
ExitCommandMode();
}
// TODO save this configuration
}
/*
Enter command mode by sending: $$$
Characters are passed until this exact sequence is seen. If any bytes are seen before these chars, or
after these chars, in a 1 second window, command mode will not be entered and these bytes will be passed
on to other side.
*/
void WiFly::EnterCommandMode()
{
FlushRX();
delay(1000); // wait 1s as instructed above
m_printer->println("Entering command mode.");
WriteToWiFly("$$$");
WaitUntilReceived("CMD");
}
/*
exit command mode
send the "exit" command and await the confirmation result "EXIT"
*/
void WiFly::ExitCommandMode()
{
WriteToWiFlyCR("exit");
WaitUntilReceived("EXIT");
}
Step 9: Programming step 3: Searching Twitter with TCP/IP port 80
Http is just TCP/IP on port 80
for example:
"Open www.google.com 80"
will open a Http connection to www.google.com.
Twitter actually requires more of the Http protocol than google.
For example, the "Host" field is often required in case there's more than one
domain name mapped to the server's IP address so it can tell which
website you actually want.
Twitter also requires a final linefeed and carriage return ("\r\n")
I use search.json rather than search.atom to give results in non-html format, and more easily parsed. (see apiwiki.twitter.com/Twitter-API-Documentation)
for example:
"Open www.google.com 80"
will open a Http connection to www.google.com.
Twitter actually requires more of the Http protocol than google.
For example, the "Host" field is often required in case there's more than one
domain name mapped to the server's IP address so it can tell which
website you actually want.
Twitter also requires a final linefeed and carriage return ("\r\n")
"GET /\n"
"Host: server\r\n"
"\r\n"
"Host: server\r\n"
"\r\n"
I use search.json rather than search.atom to give results in non-html format, and more easily parsed. (see apiwiki.twitter.com/Twitter-API-Documentation)
/*
Parameters: The server to telnet into, the get command that needs to be sent, a custom HtmlParser that
is called every time a character is received. The parser is responsible for processing the HTML
that is returned.
*/
bool WiFly::HttpWebRequest(const char* server, const char* getCommand, HtmlParser* parser)
{
m_printer->println(getCommand);
FlushRX();
FlushRX();
// Enter command mode
EnterCommandMode();
FlushRX();
// open a TCP connection, port 80 for HTTP
WriteToWiFly("open ");
WriteToWiFly(server);
WriteToWiFlyCR(" 80");
bool openOK = WaitUntilReceived(COMM_OPEN);
if (openOK == false)
{
m_printer->println("open port failed!");
delay(1000);
WriteToWiFlyCR("close");
WaitUntilReceived(COMM_CLOSE);
ExitCommandMode();
return false;
}
// eg. "GET /search.json?q=foo HTTP/1.1\r\n"
WriteToWiFlyCRLF(getCommand);
// eg. "Host: search.twitter.com\r\n"
WriteToWiFly("Host: ");
WriteToWiFlyCRLF(server);
// "\r\n"
WriteToWiFlyCRLF("");
// now wait for the response
int timeOut = 0;
bool ok = false;
while(timeOut < 5000)// timeout after 5 seconds
{
if((ReadCharFromWiFly(LSR) & 0x01))
{
char incoming_data = ReadCharFromWiFly(RHR);
m_printer->print(incoming_data,BYTE);
bool done = parser->Parse(incoming_data);
if (done)
{
ok = true;
break;
}
timeOut = 0; //reset the timeout
}
else
{
delay(1);
timeOut++;
}
}
FlushRX();
// disconnect TCP connection.
WriteToWiFlyCR("close");
WaitUntilReceived(COMM_CLOSE);
ExitCommandMode();
return ok;
}
Step 10: Programming step 4: RGB LED
A
simple library for setting the colour of an RGB LED. The library will
fade between the colours as the world mood changes, and will flash if it
is a significant change in mood.
*** update ***
If you find the colours look wrong, try removing the "255 -" from the analogWrite calls.
Thanks to shobley for finding this.
More info at http://www.stephenhobley.com/blog/2010/06/11/arduino-world-mood-light-using-twitter-and-wishield/
*** end update ***
*** update ***
If you find the colours look wrong, try removing the "255 -" from the analogWrite calls.
Thanks to shobley for finding this.
More info at http://www.stephenhobley.com/blog/2010/06/11/arduino-world-mood-light-using-twitter-and-wishield/
*** end update ***
/*
The led is initially set to be currentColorID and over time will fade
to desiredColorID with a time delay, fadeDelay, measured in ms, between
each step. No effort is made to scale the step size for each rgb
channel so each may not complete at the same time.
*/
void LED::FadeTo(int desiredColorID)
{
// check for valid colorID
if (desiredColorID >= NUM_COLORS ||
desiredColorID < 0)
{
//logger.log("invalid Color id")
return;
}
// get a local copy of the colors
Color currentColor;
currentColor.r = Colors[m_currentColorID].r;
currentColor.g = Colors[m_currentColorID].g;
currentColor.b = Colors[m_currentColorID].b;
Color desiredColor;
desiredColor.r = Colors[desiredColorID].r;
desiredColor.g = Colors[desiredColorID].g;
desiredColor.b = Colors[desiredColorID].b;
bool done = false;
while (!done)
{
// move each of r,g,b a step closer to the desiredColor value
if (currentColor.r < desiredColor.r)
{
currentColor.r++;
}
else if (currentColor.r > desiredColor.r)
{
currentColor.r--;
}
if (currentColor.g < desiredColor.g)
{
currentColor.g++;
}
else if (currentColor.g > desiredColor.g)
{
currentColor.g--;
}
if (currentColor.b < desiredColor.b)
{
currentColor.b++;
}
else if (currentColor.b > desiredColor.b)
{
currentColor.b--;
}
// write the new rgb values to the correct pins
analogWrite(m_redPin, 255 - currentColor.r);
analogWrite(m_greenPin, 255 - currentColor.g);
analogWrite(m_bluePin, 255 - currentColor.b);
// hold at this color for this many ms
delay(m_fadeDelay);
// done when we have reach desiredColor
done = (currentColor.r == desiredColor.r &&
currentColor.g == desiredColor.g &&
currentColor.b == desiredColor.b);
} // while (!done)
m_currentColorID = desiredColorID;
}
Step 11: Programming 5: Computing the World Mood
The
mood light should be responsive enough to reflect what has just
happened in the world, but it must not be so overly sensitive as to be
susceptible to noise, and also not be too sluggish to be late in
informing you of a big world event.
The important thing is to carefully normalize and smooth the data, and to adjust the thresholds to give the right level of responsiveness and alarm. (i.e. it should flash when a headline news story
happens and not when a TV show starts, GMT)
Emotion, mood, and temperament
Firstly, the "world's emotion" is calculated by searching twitter for tweets with each of the 7 mood types (love, joy, surprise, anger, fear, envy, sad) .
A measure of "tweets per minute" is used to calculate the current emotion. A higher number of tweets per minute suggests more people are currently feeling that emotion.
Emotions are volatile, so these short-lived emotional states are smoothed over time by using a "fast exponential moving average"
(see en.wikipedia.org/wiki/Moving_average#Exponential_moving_average)
This gives us ratios for the different moods.
Each mood ratio is then compared to a base line, a "slow exponential moving average", that I call the "world temperament".
The mood that has deviated furthest from its baseline temperament value is considered to be the current world mood.
The deviation is measured as a percentage, so, for example, if fear changes from accounting for 5% of tweets to 10% then this is more significant than joy changing from 40% to 45% (They are both a +5% in additive terms, but fear increased by 100% in multiplicative terms.)
Finally, the world temperament values are tweaked slightly in light of this new result. This gives the system a self adjusting property so that the world temperament can very slowly change over time.
These values in WorldMood.pde are used to adjust how sensitive the system is to information.
#define emotionSmoothingFactor (0.1f)
#define moodSmoothingFactor (0.05f)
#define moderateMoodThreshold (2.0f)
#define extremeMoodThreshold (4.0f)
The important thing is to carefully normalize and smooth the data, and to adjust the thresholds to give the right level of responsiveness and alarm. (i.e. it should flash when a headline news story
happens and not when a TV show starts, GMT)
Emotion, mood, and temperament
Firstly, the "world's emotion" is calculated by searching twitter for tweets with each of the 7 mood types (love, joy, surprise, anger, fear, envy, sad) .
A measure of "tweets per minute" is used to calculate the current emotion. A higher number of tweets per minute suggests more people are currently feeling that emotion.
Emotions are volatile, so these short-lived emotional states are smoothed over time by using a "fast exponential moving average"
(see en.wikipedia.org/wiki/Moving_average#Exponential_moving_average)
This gives us ratios for the different moods.
Each mood ratio is then compared to a base line, a "slow exponential moving average", that I call the "world temperament".
The mood that has deviated furthest from its baseline temperament value is considered to be the current world mood.
The deviation is measured as a percentage, so, for example, if fear changes from accounting for 5% of tweets to 10% then this is more significant than joy changing from 40% to 45% (They are both a +5% in additive terms, but fear increased by 100% in multiplicative terms.)
Finally, the world temperament values are tweaked slightly in light of this new result. This gives the system a self adjusting property so that the world temperament can very slowly change over time.
These values in WorldMood.pde are used to adjust how sensitive the system is to information.
- Do you want it to pick up when people are happy about a sport result or scared about the weather?
- Or would you prefer to only track big events like natural disasters or terrorist attacks?
#define emotionSmoothingFactor (0.1f)
#define moodSmoothingFactor (0.05f)
#define moderateMoodThreshold (2.0f)
#define extremeMoodThreshold (4.0f)
MOOD_TYPE WorldMood::ComputeCurrentMood()
{
// find the current ratios
float sum = 0;
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
sum += m_worldMoodCounts[i];
}
if (sum < 1e-4f)
{
#ifdef DEBUG
m_printer->print("unexpected total m_worldMoodCounts");
#endif // ifdef DEBUG
return m_worldMood;
}
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
m_worldMoodRatios[i] = m_worldMoodCounts[i] / sum;
}
// find the ratio that has increased by the most, as a proportion of its moving average.
// So that, for example, an increase from 5% to 10% is more significant than an increase from 50% to 55%.
float maxIncrease = -1.0f;
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
float difference = m_worldMoodRatios[i] - m_worldTemperamentRatios[i];
if (m_worldTemperamentRatios[i] < 1e-4f)
{
#ifdef DEBUG
m_printer->print("unexpected m_worldTemperamentRatios");
#endif // ifdef DEBUG
continue;
}
difference /= m_worldTemperamentRatios[i];
if (difference > maxIncrease)
{
maxIncrease = difference;
m_worldMood = (MOOD_TYPE)i; // this is now the most dominant mood of the world!
}
}
// update the world temperament, as an exponential moving average of the mood.
// this allows the baseline ratios, i.e. world temperament, to change slowly over time.
// this means, in affect, that the 2nd derivative of the world mood wrt time is part of the current mood calcuation.
// and so, after a major anger-inducing event, we can see when people start to become less angry.
sum = 0;
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
if (m_worldTemperamentRatios[i] <= 0)
{
#ifdef DEBUG
m_printer->print("m_worldTemperamentRatios should be initialised at construction");
#endif // #ifdef DEBUG
m_worldTemperamentRatios[i] = m_worldMoodRatios[i];
}
else
{
const float a = m_moodSmoothingFactor;
m_worldTemperamentRatios[i] = (m_worldTemperamentRatios[i] * (1.0f - a)) + (m_worldMoodRatios[i] * a);
}
sum += m_worldTemperamentRatios[i];
}
if (sum < 1e-4f)
{
#ifdef DEBUG
m_printer->print("unexpected total m_worldTemperamentRatios total");
#endif // #ifdef DEBUG
return m_worldMood;
}
// and finally, renormalise, to keep the sum of the moving average ratios as 1.0f
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
m_worldTemperamentRatios[i] *= 1.0f / sum;
#ifdef DEBUG
m_printer->print("temperament ratio: ");
m_printer->println(m_worldTemperamentRatios[i]);
#endif
}
#ifdef DEBUG
// debug code - check sum is 1.
sum = 0;
for (int i = 0; i < NUM_MOOD_TYPES; i++)
{
sum += m_worldTemperamentRatios[i];
}
if (sum > 1.0f + 1e-4f || sum < 1.0f - 1e-4f)
{
m_printer->println("unexpected renormalise result");
}
#endif // #ifdef DEBUG
return m_worldMood;
}
Step 13: Enjoy!
Some possible extensions include:
I am very interested to hear any comments, corrections or questions. Please do contact me, if you so wish.
- Making it multilingual and not just English speaking places.
- Perhaps just associating with a keyword, for example every tweet must contain the word "Obama", then you could gauge public opinion on just that subject.
- Location specific. Perhaps you just care about your town or country. Twitter allows you to use the geocoding to do this.
- Make it tweet what the world mood is so as to complete the circle
- Ability to connect to it from a computer to see what keywords people are so emotive about.
I am very interested to hear any comments, corrections or questions. Please do contact me, if you so wish.
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