Category Archives: opensource

RMAP – important resource

Weather-Station-128x128I would like to be the first or one of first people quoting it: RMAP project. It is a very interesting initiative for a network of environmental data agents. The acronym stays for Rete di Monitoraggio Ambientale Partecipativo (Environmental and Participated Monitoring Network).

RMAP provides a whole set of – absolutely open source – tools, from hardware sensors up to web server for data gathering and distributing.

I am sure you will hear again about it. For the meanwhile… stay in touch.

Raspberry Pi: how to read pin status without shutting it down in Python

From now on, sometimes I would like to publish results of internet searching… that I did NOT find. The results I wanted and I found after just after a long wandering.


Raspi-PGB001_reasonably_small When you work with Raspberry Pi, and you are controlling something via output port, say a relay, you can have set a status on it, i.e. you can have put it HIGH, with the usual

import RPi.GPIO as GPIO
GPIO.setup(25, GPIO.OUT)
GPIO.output(25, HIGH)

Then, some times after, you are willing to know if pin 25 is HIGH o LOW. You have forgot it, or you are not you, but another person willing to know that. Problem: if you set pin 25 as input, you suddenly switch off it. So DO NOT DO this, in the same or another program:

GPIO.setup(25, GPIO.IN)
print GPIO.input(25)

because you will always get a False, at least with default pullups.

Fortunately the answer is simple: just set that pin as output… but read it!

GPIO.setup(25, GPIO.OUT)
print GPIO.input(25)

and you will get a True or a False depending on the real status.

LibreOffice vs OpenOffice 1-0 in pdf editing

I recently discovered that I can open directly (File->Open) pdfs  in my LibreOffice on Windows. I am eager LibreOffice logoto try in Ubuntu at home. Anyway, as presented in this interesting column, the same is not valid for OpenOffice: sure, you can use an extension, but it is a frankly awkward path you need follow…

LibreOffice opens it in LibreOffice Draw, and you can edit it like any other Draw document, so you can alter, delete, or add any item you like. If you, as usual for me, just want to “edit pdf”, remember to export to pdf exiting!

How I met Ubuntu Linux

In the simplest way: I was a lazy Windows user, but curious about Linux. I remembered I had tried something many years before, and I had a vague but not so good memory: yes, pretty, but too difficult, good for initiates.

But when my old PC broke, I changed a lot of hardware, and I didn’t want to fuss over neither complicated and expensive Windows licenses, nor piracy. So I gave Linux a chance: I took the usual (in 2008) Ubuntu CD-ROM sold with a magazine issue and put it in the tray. If you, dear Ubuntu, start smoothly, I will foster you. And that’s what happened.

Everything went fine, no strange questions, no locking. Ubuntu was not so difficult, and much, much more similar to my usual environment than I expected. Five years have passed since then, and now Ubuntu is my usual environment.

So, dear reader, please give you too a chance to Linux: the only thing you really risk, if you reflect, is to find a free and live resource!

USB Serial Light Adapter for Arduino in Windows 7 x64

Arduino Ethernet

Arduino Ethernet

I am now trying to use Arduino Ethernet, in order to communicate in LAN with Arduino. Arduino Ethernet allows you to handle just only one board, saving space and money (you could have everything running in – almost – the same way by adding an Ethernet shield to a standard Arduino UNO).

USB serial adapter

USB serial adapter

It seems a straightforward operation, but a problem arises: the board lacks a USB port. A little (reusable) adapter USB-serial is the simplest solution.

Yes, but in my Windows 7 x64 environment the way turns out to be very steep. I searched the net thoroughly. At the end I found, buried in a technical document of FTDI Ltd. about drivers installation, at chapter 5.4, the indication that their driver will not install on Windows 7 x64. In general

Windows 7 x64 OS will only allow certified drivers to be installed. The certified driver supplied by FTDI will work with VID 0403 and PID 6001 for FT232 and FT245 devices. It will also work with VID 0403 and PID 6010 for FT2232 devices and VID 0403 and PID 6011 for FT4232.
If you have a product where the manufacture has customised the driver but has not re-certified it, then the driver will not load. You should contact your vendor to determine if they will support Windows 7 x64.

So, I’ll now retry with Ubuntu. Can anyone suggest other solutions to this problem?

My favorite things – what I look for in applications

MaToolsn is a tool-using animal. Without tools he is nothing, with tools he is all  – Carlyle, Thomas

This time I present an important (for me) list of applications. They meet my own criteria for choosing them.

They aim at solving problems already solved for a long time. So they are not experimental, but built on long experience in their field. Hence they are mature to be developed by open source community without depriving the very first developers of their somehow fair reward. But I find quite annoying revenues of a position (so popular here in Italy), even if they are perfectly legitimate.

Take Microsoft Word, good solution for word processing twenty years ago, when alternatives were not so robust and appealing. But more or less around the end of last century novelties ran out: you were able to organize your document in every possible way, with styles, formatting, image insertion, movie insertion (! – do you really need them?)… From then on, it was time to give room to free developing.

Going back to my criteria for applications, the second one is that they run on both Windows AND Linux. I work using both of them, and I don’t want to change my way of work every time I change location.

Interestingly, I discovered that – nowadays – finding solutions meeting my criteria is really easy!

ownCloud… not yet cloud

ownCloud logo

It’s now just one month since I installed ownCloud on my Ubuntu machine. Everything started when I realized I needed something similar to Dropbox, but totally mine. I wanted something faster than it,  with the possibility to grow without a specific limit, and without a monthly fee.
As I wrote in a previous post, I also explored Google Drive, directly comparable with Dropbox. I found that the both of them are very good products, but they share the dependence from internet band, surely narrower than the one in your LAN. So you cannot use them for your movies or CD mp3 version collection. And, yes, I don’t like too much it, having to pay a monthly fee for, say, 300 GB of data, if you really use just a handful of them.
So I wandered a lot around the net to find something similar, but installable in your machine, and I discovered this beautiful open source project, young but not too… unripe.

ownCloud is what I would define a sharing tool. Thanks to web power, it allows you to make your world accessible from everywhere: files, music, pictures, contacts. In concrete terms, it is a web application, based on a web server (usually Apache) and a database (usually mySql), taking care of your files and making them available via a standard browser.

The reason that initially pushed me was that you can install a client in your system allowing you to align a local copy of a directory tree with the one in charge of ownCloud – exactly like Dropbox.

Just to help you to better get the concept, ownCloud is very, very similar to the kind of software mounted on NAS like the QNAP or Synology ones. But in this case you are completely tied to the manifacturer by its proprietary software.

As I said, I installed it on my not-so-performant machine, and I found quite nice that it was not too difficult to install and it performs well.

On the side of access, obviously, if you don’t run a public server (in house or with an internet provider) you can make your private ownCloud accessible by the whole internet via Dynamic DNS.

Finally, a list of service providers exist, that rent ownClouds on their server. I consider it a strong confirmation of robustness of software.

The only funny consideration about ownCloud, at the end, is that – for now – it is not based on cloud! Authors are anyway working actively in order to add this little feature…