Tuesday, 7 July 2015

Analog reader

An one day project to create an analog reader for some scientific instruments. Objective of the project is to make an interface between any analog sensors to a computer. Her we choose the following ingredients;

-Arduino Uno to read analog signals and send messages to a computer through a serial port
-pyserial to get the serial input to python environment
-matplotlib
-Bokeh to visualise the analog signal in real-time




What we have done!
1. Make sure the Arduino IDE and driver are already installed
2. Python2.7 and pyserial must be installed. Here we use Anaconda and pyserial need to be installed by "$conda install pyserial" on Windows and "pip install pyserial" on Unix.
3. Install Bokeh
4. Then we made a simple implementation for communication between Uno and PC by using the codes here.

Tuesday, 28 April 2015

cluster cheat sheet

Copy files between machines:
>>pscp localfile user@host:path

Get twitter keys
Go to https://apps.twitter.com/

Install MySQLdb
>>conda install mysql-python

User
check user detail
>>sudo cat /etc/passwd
delete user home directory
>>sudo userdel -r [username]
ec2 passwd enabled-- http://www.cyberciti.biz/faq/howto-linux-add-user-to-group/
Storage usage
>>sudo du -sh /home/
or
>>sudo df -h

Screen sharing
>>screen -S sessionName
>>screen -x

Starcluster
Error: Too many open files (sinaler.cpp:300)-- https://flenniken.net/blog/65/

Thursday, 12 February 2015

Qt creator msvc2013 + video player

I spent hours to make qml video sample run on Window 8. This should be noted for others who want to use Qt Creator on Windows (with Ubuntu is a lot easier).

The video sample needs OpenGL. However gl.h for pre-built qt-libraries msvc2013 require external OpenGL from Window SDK . Actually it is quite straightforward, if I could find the SDK directly. I wouldn't spent hours on this issue. The problem was on Qt web page they didn't point to the download link then I went to this page and install almost everything in the page until I found the right installer. So, if you have the similar problem and get an error message like below then you just install the Window SDK. All the best!

error: C1083: Cannot open include file: 'GL/gl.h': No such file or directory

Tuesday, 3 February 2015

ipcluster setup

setup ipcluster

1. install IPython please check here
2. it is better to make a snapshot at this point
3. create a IPython.parallel profile
      >>ipython profile create --parallel -profile=[profile_name]
4. find profile/ipcontroller_config.py and edit
            c = get_config()
      c.HubFactory.ip='*'
5. start a controller with --ip=[contoller_ip]
***if do the 5th step, the  3rd and 4th is unneesary

           ipcontroller --ip=10.0.1.74
    or
           ipcontroller start --ip=10.0.1.74


6. copy ipcontroller-engine.json from controller (10.0.1.74) to all engines (10.0.1.90 and the rest) by executing a script

            scp /home/ubuntu/.config/ipython/profile_default/security/ipcontroller-engine.json ubuntu@10.0.1.90:/home/ubuntu/.config/ipython/profile_default/security/

7. start engine by
            ipcluster engines
    or
            ipcluster engines --n=8




Tuesday, 13 January 2015

setup Hadoop

In cs426 we're going to use Hadoop platform and the setup instructions are following:
CDH5 and  Hortonworks


Useful hdfs commands here