ChickenProp

I turned my Raspberry Pi into a robot, controlled by a Wii nunchuk. It's surprisingly easy to do - at least, surprisingly to me, who has not previously made a robot. But because it's surprising, it might help others to have a guide, so here one is.

Parts

I'm linking to SKPang for most of these, but Sparkfun and Adafruit would be good places to look if you're in the US.

(If you're in the UK, a word of caution - I bought motors and some other stuff from Sparkfun to save £7 over SKPang, but the package got stopped at customs and I had to pay £4 VAT and £8 handling fees. My understanding is that this will only happen on packages whose contents are worth more than £15, but you'd be a fool to trust me on this. It didn't happen when I spent £20 at Adafruit or £5 at Sparkfun. YMMV.)

• Raspberry Pi - for the robot logic. An Arduino or similar could be substituted (though the software would need to be rewritten).

max-mapper

var serialport = require('node-serialport')

var sp = new serialport.SerialPort("/dev/ttyO3", { 
  parser: serialport.parsers.raw,
  baud: 9600
})

sp.on('data', function(chunk) {
  console.log(chunk.toString('hex'), chunk.toString(), chunk)
})

max-mapper

var gpio = require("gpio")
var gpio22, intervalTimer

// Flashing lights if LED connected to GPIO22
gpio22 = gpio.export(22, {
  ready: blinkLED
})

function blinkLED() {
  intervalTimer = setInterval(function() {

rcrowley

package main

import (
	"log"
	"net"
	"os"
	"os/signal"
	"sync"
	"syscall"
	"time"

willurd

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

natritmeyer

require 'net/http'

class HttpClient
  def initialize(base_url, username = nil, password = nil)
    @base_url = base_url
    @username = username
    @password = password
  end
  
  def get(path, headers = {})

plentz

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

kevinburke

# Twilio HTTP HAProxy Configuration 
# Version: 0.1

global
        daemon
        log 127.0.0.1 local0 info
        maxconn 60000
        spread-checks 3

octplane

Life and death of Unicorns

The introduction of our Unicorn management tool, Polycorn.

Photo by Protohiro from Flickr

At Fotopedia, we use Unicorn to serve our main Rails application. Every day, we restart our application several times, spawning and killing hundred of Unicorns. Managing graceful restarts is a complex task, and requires careful monitoring and command. This article introduces our tool Polycorn, a Unicorn management program.

[[MORE]]

tadast

# 1) Create your private key (any password will do, we remove it below)

$ cd ~/.ssh
$ openssl genrsa -des3 -out server.orig.key 2048


# 2) Remove the password

$ openssl rsa -in server.orig.key -out server.key