My participation in Global Hackathon

The past weekend I was lucky enough to participate in an event held by Koding (http://koding.com) titled "Global Hackathon" (https://koding.com/Hackathon).

Hackathon - is a kind of time-limited events, where participants work on projects for which in ordinary daily life there is no time as a rule. The main idea is to bring the idea to the finished prototype of the final product in the shortest possible time. Hackathon is named this way because participants can use all possible tools and ways to achieve this goal.

The event was attended by 2000 teams from all around the world, selected from more than 19,000 applications. Maximum number of participants in the team was equal to 5. Many people like me was not fortunate enough to find teammates and had to work alone. 51 of the judges will find winners among completed projects and the most worthy of them will be awarded.

Arduino without IDE

For my pet project I need to upload sketches to Arduino board connected to RaspPI. As usual I have only SSH access to PI and don't want to install a lot of unnecessary packages. So the only one thing you have to install it arduino-mk package:

 $ sudo apt-get install arduino-mk  

RFID sensor (Funduino RFID-RC522)

Recently I bought a set of Arduino-compatible components including RFID sensor (RC522).

After short search I've found good tutorial telling how to use this sensor, downloaded a library and connected sensor to my Arduino (be careful there is a typo in original blog post):

• MOSI: Pin 11
• MISO: Pin 12
• SCK: Pin 13
• SS: Pin 10
• RST: Pin 5
• GND: Gnd
• VCC: 3V3

Connect RaspPI to WiFi

Recently I've ordered two WiFi dongles for my Raspberry PI home project and today I received a parcel.

Prices:
2 x Wireless Adapter Network LAN Card 802.11n/g/b 2.4GHz - $3.41 / piece

Honestly said I had to investigate this topic before purchase, but in fact when I connected it to PI and set up wireless connection I was upset - it seemed not working.

Ultrasonic Sensor: first try

After few weeks waiting they finally came to me direct from China: my new Arduino Nano and a couple of ultrasonic sensors.

Price:

• 1 x Ultrasonic Module HC-SR04 Distance Measuring Transducer Sensor - $2.56 / piece
• 1 x Funduino Nano 3.0 controller - $7.89 / piece.

As soon as I have time I decided so do simple experiment.

First of all I connected VCC and GND pins to common rails and then to corresponding pins of ultrasonic sensor. After that I connected Trigger to Pin 3 and Echo to Pin 2 of Arduino board. As in many existing examples I decided to output signal through Piezo Buzzer. I simply connected Pin 4 of Arduino to positive leg of buzzer and the other leg to common ground.

API documentation for SBT project

Laika can help you easily add documentation to your SBT project. Whole process is described here and following list contains necessary steps:

1. Add a line to your project/plugins.sbt file
   

   addSbtPlugin("org.planet42" % "laika-sbt" % "0.5.0")

2. These lines to build.sbt
   

   import laika.sbt.LaikaSbtPlugin.{LaikaPlugin, LaikaKeys}
   import LaikaKeys._
   LaikaPlugin.defaults

3. If you want to redefine default settings
   

   sourceDirectories in Laika := Seq(new java.io.File("app/docs"))
   includeAPI in Laika := true

4. Build documentation by executing following command from SBT console
   

   laika:site  

Change Jenkins default port on Mac

If you want to run Jenkins locally on Mac OS X and change default port 8080 you have to change httpPost parameter using following command:

sudo defaults write /Library/Preferences/org.jenkins-ci.plist httpPort 9000

 After that you have to restart Jenkins:

sudo launchctl unload /Library/LaunchDaemons/org.jenkins-ci.plist
sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist

Thats it.

CloudControl - setup Scala/Play application

CloudControl (https://www.cloudcontrol.com) is a Platform as a Service solution.

You can deploy on it Java  NodeJS  PHP  Python  Ruby applications as well as a lot of Third-Party Buildpacks including Scala/Play (https://github.com/heroku/heroku-buildpack-play). Its main particularity is that it supports vertical and horizontal scaling.

The following guide explains how to deploy your application on CloudControl.