Bdunk

Arduino from shell

2013-05-06T00:00:00+00:00

If you want to upload a program to Arduino from the command line can be done with inotool.

First install dependences:

apt-get install python-setuptools
apt-get install python-configobj
apt-get install python-jinja2
apt-get install python-serial

For serial tests:

apt-get install picocom

Obtain source and compile it:

git clone git://github.com/amperka/ino.git
make install

Start a project:

mkdir blink
cd blink
ino init

Change it src/sketch.ino with your program. A sample:

#define LED_PIN 13

void setup()
{
    pinMode(LED_PIN, OUTPUT);
}

void loop()
{
    digitalWrite(LED_PIN, HIGH);
    delay(100);
    digitalWrite(LED_PIN, LOW);
    delay(900);
}

In my case I'm using Arduino Duemilanove so I created a configuration file ino.ini (in the same project folder):

[build]
board-model = atmega328

[upload]
board-model = atmega328

You will need arduino-core:

apt-get install arduino-core

Build project

ino build

And now upload to Arduino:

ino upload

My Arduino:

You can see a good tutorial here.

123: The Black Hole Number

2013-02-22T00:00:00+00:00

Start with any number, say 9288759
Count the number of even digits, the number of odd digits, the total number of digits.
You get 347
Repeat and you get 123
Repeat and you get 123
Repeat and you get 123
...
Once you reach 123, you never get out, just as reaching a black hole in physics implies no escape.

A simple program in Node JS to test:

/
Moncho Pena
2013-02-22
/
var myargs = process.argv.slice(2);
if (myargs[0]) {
var number=myargs[0];
number=stripAlphaChars(number);
if (number=='') {
number=0;
}
if (number<100) {
console.log('Please use a number greater than 99');
} else {
console.log(number);
var test=convert(number);
while (test[3]!=123) {
test=convert(test[3]);
}
}
} else {
console.log('Use: node 123.js number');
}
function stripAlphaChars(source) {
var out = source.replace(/[^0-9]/g, '');
return out;
}
function convert(number) {
var numbers= new Array();
var res= new Array();
var pair=0;
var odd=0;
for (var i=0;i<number.length;i++) {
var control=number.substr(i, 1);
if ((control%2)==0) {
pair++;
} else {
odd++;
}
}
res[0]=pair;
res[1]=odd;
res[2]=number.length;
var super_number=res[0].toString()+res[1].toString()+res[2].toString();
console.log(super_number);
res[3]=super_number;
return res;
}

Running:

I've read this curiosity on Gaussianos.

Every Possible Photograph in Processing

2013-02-11T00:00:00+00:00

I read in Microsiervos an interesting article about Every Possible Photograph.

I made a Processing program that generates a random image each time you make a click.

//Globals

int w=800;
int h=600;
  
int block_x = 10;
int block_y = 10;
  
int blocks_x=ceil(w/block_x);
int blocks_y=ceil(h/block_y);

void setup() {  
  size(w, h);
}

void draw() {
  
  if (mousePressed) {
    makeit();
  } 
  
}

void makeit() {
  
  for (int i=0;i<blocks_y;i++) {

    int coord_y=i*block_y;
  
    for (int w=0;w<blocks_x;w++) {
      int coord_x=w*block_x;
      color c1 = color(random(0,255), random(0,255), random(0,255));
      fill(c1);
      rect(coord_x, coord_y, coord_x+block_x, coord_y+block_y);
    }
    
  }

}

What is the possibility of hitting a recognizable image? :-)

TWiki on Nginx

2012-12-22T00:00:00+00:00

I like Twiki and I love Nginx. Can they work together? Yes they can.

First: we need a CGI for Nginx. I used to use spawn-fcgi but is not updated for 4 years. So i tried with Simple CGI support for Nginx.

git clone https://github.com/gnosek/fcgiwrap
autoreconf -i
./configure
make
make install

Maybe you need install:

apt-get install libfcgi-dev

A script for start FCGIWrap

#!/usr/bin/perl

use strict;
use warnings FATAL => qw( all );

use IO::Socket::UNIX;

my $bin_path = '/usr/local/sbin/fcgiwrap';
my $socket_path = $ARGV[0] || '/tmp/cgi.sock';
my $num_children = $ARGV[1] || 1;

close STDIN;

unlink $socket_path;
my $socket = IO::Socket::UNIX->new(
    Local => $socket_path,
    Listen => 100,
);

die "Cannot create socket at $socket_path: $!\n" unless $socket;

for (1 .. $num_children) {
    my $pid = fork;
    die "Cannot fork: $!" unless defined $pid;
    next if $pid;

    exec $bin_path;
    die "Failed to exec $bin_path: $!\n";
}

Now install TWiki. Obtain source from TWike Download Page.

Create LocalLib.cfg and put all path (In my case):

$twikiLibPath = "/var/twiki/lib";
$TWiki::cfg{ScriptUrlPaths}{view} = '';
$TWiki::cfg{ScriptUrlPaths}{edit} = '/edit';

And now nginx configuration:

server {
        listen       81;
        server_name  192.168.1.113;
        
        access_log /var/log/nginx/acces_twiki.log;
        error_log /var/log/nginx/error_twiki.log;

         root /var/twiki;
        index index.html;
        
        location = /favicon.ico {
          return 204;
          access_log     off;
          log_not_found  off;
        }


        rewrite ^/([A-Z].*)  /bin/view/$1;
        rewrite ^/edit/(.*)  /bin/edit/$1;

        location ~ ^/pub/ { allow all; }

        location ~ ^/bin/configure {
          allow all; #remember put deny all after finish configuration
          fastcgi_pass   unix:/tmp/cgi.sock;
          include        fastcgi_params;
          fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        }

        location ~ ^/bin/ {
          allow all;
          fastcgi_pass   unix:/tmp/cgi.sock;
          fastcgi_split_path_info  ^(/bin/[^/]+)(/.*)$;
          include        fastcgi_params;
          fastcgi_param  PATH_INFO        $fastcgi_path_info;
          fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
         }

    }

And go to web page!

How to change prompt colour and motd

2012-11-30T00:00:00+00:00

When you work (hard) with many servers on terminal you need to distinguish them. The best way is.

Set the prompt

Add line to .bashrc:

export PS1="\e[1;36m\u@\h-super-dev-\w# \e[m"

Don't forget reload file:

source .bashrc

Ok there are lots of colours.

A list:

Black       0;30     Dark Gray     1;30
Blue        0;34     Light Blue    1;34
Green       0;32     Light Green   1;32
Cyan        0;36     Light Cyan    1;36
Red         0;31     Light Red     1;31
Purple      0;35     Light Purple  1;35
Brown       0;33     Yellow        1;33
Light Gray  0;37     White         1;37

Changing the motd file

When you start system you can change initial message in /etc/motd. Mental note: Don't forget make a copy when you change it.

And add colour to your live! Simple sample motd:

[moncho@bdunk.com]$ echo -en "\033[1;34m" > /etc/motd
[moncho@bdunk.com]$ echo "Text of your motd file....." >> /etc/motd
[moncho@bdunk.com]$ echo -en "\033[0m" >> /etc/motd

You can add funny ASCII Artwors:

Using Markdown in Express

2012-11-26T00:00:00+00:00

Ok. I'm a geek and I like markdown. I've been testing with Express and wanted to use markdown.

$ npm install -g express
$ express --sessions --css stylus myapp
$ cd myapp && npm install
$ node app.js

Now you can go to http://localhost:3000 and see The Express Default Page.

If we want use markdown we need install:

$ npm install node-markdown

Let's create a new markdown file into views:

$ vi views/index.mdown

Content:

***Ok*** this is a test

In app.js file add this files:

...
, fs = require('fs')
...
var md = require("node-markdown").Markdown;
...
var index_file = fs.readFileSync(__dirname + '/views/index.mdown', "utf8");
app.locals.body = md(index_file);
...

In views change file index.jade adding:

!{body}

Wonderful! I really like express!

Sent an email when the iMac is at a specified price

2012-07-19T00:00:00+00:00

The other day a friend asked me to let him know if I saw a special offer of iMac. I don't wanna be watching every little time so I made a script.

#!/bin/bash

FILE=/root/no_mess
URL="http://store.apple.com/es/browse/home/specialdeals/mac/imac/27"
PRICE="1.395"

if [ ! -f $FILE ]
then

    LINE=`curl -s $URL | grep "${PRICE}"`

    if [ -n "${LINE}" ]
    then
        echo "Go to $URL" | mail -s "Ok let's go" my.personal@email.com > $FILE
    fi

fi

All that remains is to incorporate to the Cron.

How to know the outside temperature

2012-06-24T00:00:00+00:00

From this web meteogalicia i can know the weather:

If I only want see the degrees i use commands: curl, grep see and awk.

curl --silent --data "idEst=10115&tiporede=automaticas&idprov=2" http://www2.meteogalicia.es/galego/observacion/estacions/contidos/datosxeralestacion.asp | grep -m 1 "deg" | awk '{print $2}' | sed 's/class="negro">//' | sed 's/\&deg;<\/span><\/td>//g'

How to publish an article on this website

2012-06-10T00:00:00+00:00

First: I write the article in *.mdown format.

Second: I check on my computer everything works fine.

shotgun config.ru

Third: login in heroku.

heroku login

Fourth: update the code from server.

git pull

Fifth: send to git server the changes.

git add .

git commit -a -m "How to publish"

Sixth: send to heroku server.

git push heroku master

More information about Heroku git in this page.

The sum of a sequence of odd numbers gives you the sequence for the perfect squares

2012-06-06T00:00:00+00:00

Really? We can test with a simple PHP Code:

<?php

echo '<h1>The sum of a sequence of odd numbers gives you the sequence for the perfect squares</h1>';

//The limit
$limit=1000;

$odd=array();

for ($i=1;$i<$limit;$i++) {

    if ($i%2!=0) {
        $odd[]=$i;
    }

}

$begin=0;
$end=1;

while ($end<count($odd)) {

    $write='';
    $result=0;

    for ($i=$begin;$i<$end;$i++) {

        $result=$result+$odd[$i];

        $write.=$odd[$i];

        if ($i==($end-1)) {
            $write.='=';
        } else {
            $write.='+';
        }

    }

    $write.=$result;

    echo '<h3>' . $write;

    $square=sqrt($result);

    if ($square==$end) {
        $question="Yes";
    } else {
        $question="No";
    }

    echo ' numbers=' . $end . ' sqrt(' . $result . ')=' . $square . ' Really? ' . $question . '</h3>';

    $end++;

}

?>