Sometimes we like to take a few minutes away from Hackaday to spend time with our families. But just when you take your eyes off of the incoming comments, Trolls are bound to strike. Well, [Caleb] and I found a solution to the problem in the form of a troll sniffing rat. This beady-eyed vermin sits on my desk and waits. When a trolling comment is detected its eyes glow red and an alarm is sounded. Join us after the break for more about this silly project.
Software
To pull this off I need a few things to happen. First, a way to parse our incoming comments. That’s easy, we use WordPress as our content management system and that means there’s already an RSS feed for global comments. I just need to grab that data and traverse the comment authors for known trolls (who haven’t been banned). That’s not hard to do with a Python script, especially if you take advantage of the Beautiful Soup module which sanitizes and navigates HTML and XML. My script checks the feed every two minutes, stores the number that identifies each comment so as not to have duplicate alarms, and makes decisions based on the author of that comment. A simple list of usernames is used to search for trolls, but it could be used just to notify whenever one of your favorite readers leaves a comment. The script then records a message on the standard output, and sends a coded command via a serial connection.
Here’s what the terminal output looks like:
And here’s the Python script:
#!/usr/bin/pythontrolls = [ 'Mike Szczys' , 'Caleb Kraft' ]signalAllComments = TruesignalAllAudibly = Falseimport urllib2, time, serialfrom BeautifulSoup import BeautifulSoup#start a list of comments to prevent duplicate alertsdupe = []#setup Arduino communicationsser = serial.Serial('/dev/ttyUSB0', 9600)time.sleep(5)#get list of comment identifierswhile True: #Reset Arduino from the last trigger ser.write('z'); #Get the comments html = urllib2.urlopen("http://hackaday.com/comments/feed").read() soup = BeautifulSoup(html) #Check each one for item in soup('item'): thisID = item('guid')[0].string.split('comment-')[1] if thisID not in dupe: #Add to the duplicate list for next time dupe.append(thisID) #Convert post time to local time postT = item('pubdate')[0].string parsedT = time.strptime(postT, "%a, %d %b %Y %H:%M:%S +0000") offsetT = time.mktime(parsedT) - time.timezone localPostTime = time.strftime("%m/%d/%y %H:%M:%S", time.localtime(offsetT)) #Check if this is a post we're watching author = item('dc:creator')[0].string if author in trolls: print "(" + localPostTime + ") Troll Alert: " + author + " just posted a comment" print " " + item('guid')[0].string print ser.write('a') time.sleep(1) elif signalAllComments: print "(" + localPostTime + ") New Comment from: " + author print " " + item('guid')[0].string print #audible signal? if (signalAllAudibly): ser.write('b') time.sleep(1) time.sleep(120)Hardware
Next, I needed a way to sound the alarm when the parsing script identifies a troll. In my mind the easiest/quickest way to develop hardware connected to a computer is to use an Arduino connected via USB. I have an Arduino that I’ve never actually used for a project so I thought this would be a great start. I dug up a piezo buzzer and some LEDs and started looking around to see what code examples I could repurpose.
I found a post on making music using a piezo buzzer, so I altered that code to make the sounds I desired. I also looked at the serial communication examples that come with the Arduino IDE to get communications up and running. Like I mentioned above, I’m sending an ASCII char via serial connection from my Python script. The sketch below just looks for those chars and acts accordingly. I can make the hardware light the LEDs and play a bad sound when ‘A’ is received. It plays a good sound and does nothing with the LEDs when ‘B’ comes through. Any other letter turns the LEDs off, which is what the Python script uses to reset the LEDs two minutes after the last troll alert.
//Piezo code from://http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1241248988void setup() { pinMode(7, OUTPUT); pinMode(8, OUTPUT); Serial.begin(9600);}#define PIEZO_PIN 8// defines for the frequency of the notes (.5 x freq of mid C)#define AN 220 // 440 Hz#define AS 233 // 466 Hz#define BN 247 // 493 Hz#define CN 261 // 523 Hz#define CS 277 // 554 Hz#define DN 294 // 588 Hz#define DS 311 // 622 Hz#define EN 330 // 658 Hz#define FN 349 // 698 Hz#define FS 370 // 740 Hz#define GN 392 // 784 Hz#define GS 415 // 830 Hz// defines for the duration of the notes (in ms)#define wh 1024#define h 512#define dq 448#define q 256#define qt 170#define de 192#define e 128#define et 85#define oo7 1 // 007 jingle/////////////////////////////////////////////////////////////void play_tune(int tune){ // play a tune . . . switch (tune) { // a case for each tune case 1: for (unsigned char i=0; i