Digicom Router USB current-limit Hack

Recently I’ve bought a Digicom ADSL WiFi router (RAW304G) with USB… Just to find out that you can’t attach a USB external HDD… Not enough current provided by the USB port ! WTF?!

Let’s change this…

20161119_121343.jpg

All the details are given here in my dokuwiki.

Result: a 2TB NAS from a 30€ router. Awesome !

How to solve WiFi not working in a fresh installed Linux Mint 17 (Sony Vaio, Atheros ATH9K)

While working with the USB-stick version of Linux Mint 17, the WiFi stopped to work once the OS installed…

I tried to load manually the ath9k module:

sudo modprobe ath9k

but all I could get was the following error:

modprobe: ERROR: ../libkmod/libkmod.c:556 kmod_search_moddep() could not open moddep file '/lib/modules/3.13.0-43-generic/modules.dep.bin'

SOLUTION: Reinstall or install the corresponding linux-image and reboot…

sudo apt-get install --reinstall linux-image-3.13.0-43

Ati Radeon (HD 4330) FGLRX legacy driver on Linux (Mint/Ubuntu)

The video performances of my Aspire 4810T were disappointing… I couldn’t watch a small Youtube video without experiencing lags and overheating… Not even in full screen… WTF?!

So I decided to pass to proprietary drivers, no matter what. This is how:

  • I downloaded the driver (the last version that support this card is the 13.1 Catalyst Legacy Driver)
  • I downgraded the system… Yes, the driver don’t support recent releases (the last supported versions are Mint Maya 13 and Ubuntu Precise 12.04). I opted for Maya.
  • I installed everything manually like well explained here

After this, the graphical interface didn’t work (a bad fglrx: No matching Device section for instance (BusID PCI:0@0:1:1) at boot-up)… This is because there is one more step to do (which is not present in the aforementioned guide):
in the BIOS, the option Switchable graphic needs to be set to Discrete

Immagine

After that, it worked !

Realtek SD reader mounting problems under Linux (Mint/Ubuntu)

This is a solution to SD mounting problems of a Realtek RTS5209 card read.
This affects my new Sony Vaio (SVE151G) with Linux Mint 15 but the solution can be extended to other operating systems/PCs (Ubuntu for example, and some HP notebooks).

Basically, when a SD card is inserted nothing happens… The device is not mounted and DMESG command says something like:

mmc0: error -110 whilst initialising SD card

This is how I solved the problem… :

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Farfisa Matador (611-E) 1973 Organ Repair

Immagine

A friend of mine bought this vintage keyboard: a Farfisa Matador (Mod. 611-E) coming directly from the ’70s. By the way the seller forgot to mention that, despite being very well conserved on the outside, it produced a strong and unpleasant hiss that made it almost unusable; it sounded like a out-of-tune chord, so the guy said it was just some dirt under the keys. False…

So I had the honour to put my hands inside this beautiful keyboard. I want to share this experience with you posting some photos I made during the troubleshoot process (se serve una traduzione in italiano chiedete nei commenti).

An overview of the Farfisa family can be found at combo-organ.com, luckily the schematics are available as well: Farfisa.org.

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LED Boost converter (aka “Joule Thief”) analysis

In the past I already tested a nice boost circuit that allows us to power a 3 V LED with a discharged battery (around 1 V or less). This circuit uses just one transistor, one resistor and a small transformer (1:1 ratio) and it is better known, at least on the internet, under the name of “Joule Thief”.

The theory behind this circuit seems to be obscure as we can find lot of comments and questions like: “can I add turns ?”, “can I increase the resistor ?”, “will it work with two batteries ?” and so on…

I decided to figure out the working mechanism of this smart circuit in order to understand the rules behind it and try to improve the efficiency. I’ll carry out a theoretical analysis, supported by some scope screen-shots.

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MSP430 LaunchPad: my 9600 Baud Serial Connection

I wanted to create a 9600 asynchronous serial connection with my TI LaunchPad.
I started my development from the source code of the example program that I found in it (temp. sensor with serial connection and leds modulation) but I wanted three more things: a faster link (9600 which is four times greater), a mspgcc4 compatibility (the free-software compiler that I’m using) and a CPU working at 16 MHz (instead of 1 MHz of the example).

The task is not very difficult and I carried it in a completely free environment (Ubuntu + MSPGCC + mspDebug).
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Skype non funziona con il microfono integrato su Linux Ubuntu, ecco come risolvere…

Nel mio nuovo portatile Acer Aspire 4810T, ho constatato che il microfono integrato funzionava con il registratore di suoni ma non funzionava con Skype.

Ciò è dovuto al fatto che Skype ritiene che sia un microfono stereo e, nel tentativo di rimuovere il rumore, fa la differenza dei 2 canali arrivando così ad annullare il segnale.

La soluzione è installare un mixer per PulseAudio

sudo apt-get install pavucontrol

e, una volta avviato, modificare i livelli audio del microfono, andando ad abbassare a livello 0 uno dei 2 canali.

Nelle impostazioni Skype, inoltre, va inibito l’auto-settaggio dei volumi.

How to type accents on a keyboard without them, on Ubuntu

Quando si studia una nuova lingua, può capitare di avere a che fare con lettere o accenti particolari, non presenti nella lingua natia e, più gravemente, nemmeno nella tastiera…
Esattamente ciò che mi è successo studiando francese: nella tastiera italiana non ci sono “ê” or “â”…

Fortunatamente ho trovato una soluzione estremamente comoda…

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