USB fuse bypass for RPi B rev. 0003

My raspberry pi didn’t supply enough current to the connected usb devices and I didn’t want a usb hub so something had to be done..

Got the idea from Larry_Adlards post (Sun Jun 17, 2012) to but since my rev 3 board did not have polyfuses F1 and F2 (they were shorted) I had to also remove those shorts.

The 5v line on the pi usb port is now 5.04v while before the mod it was ~4,3V with the devices attached (below spec).

Two network adapters, how to change the preferred (Windows)?

It’s decided by the Gateway metric. In my case I want to make the first one the preferred one, so I have to change the “InterfaceMetric: 20” to a value smaller than 10.

C:UsersFilip>route print
IPv4 Route Table
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric

Open Interface Properties -> Internet Protocol Version 4 Properties -> Advanced -> Uncheck Automatic metric and enter 9 -> OK. Done.

10 bit PWM on ATmega32u4 (ex. Arduino Micro)

Some magic is required to get 10 bit PWM on ATmega32u4.


  pinMode(13, OUTPUT);
  pinMode(10, OUTPUT);
  // 10-bit operation
  TC4H = 0x03; OCR4C = 0xFF;
  //Configuration of Timer 4 Registers, OC4A (D13) + 0C4B (D10)
  TCCR4A = 0b10100011;
  TCCR4B = 0b00000011;

Set PWM output value, needs to be written separately to upper and lower register, in this order!

void setPwmDutyA(int val){
  TC4H = val >> 8;
  OCR4A = 0xFF & val;
void setPwmDutyB(int val){
  TC4H = val >> 8;
  OCR4B = 0xFF & val;

Simple iptables

setup iptables for ssh, zabbix, ping, http

cat /etc/network/if-pre-up.d/*
echo -e '#!/bin/bash
/sbin/iptables-restore < /etc/iptables.up.rules' > /etc/network/if-pre-up.d/iptables
chmod +x /etc/network/if-pre-up.d/iptables
echo -e '*filter
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 10050 -s SERVERIP -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
COMMIT' > /etc/iptables.up.rules

My Debian wheezy minimal postinst

nano /etc/apt/sources.list
deb wheezy main contrib non-free
deb-src wheezy main contrib non-free
deb wheezy-updates main contrib non-free
deb-src wheezy-updates main contrib non-free
deb wheezy/updates main contrib non-free
deb-src wheezy/updates main contrib non-free
deb wheezy-backports main contrib non-free
deb-src wheezy-backports main contrib non-free
aptitude update
aptitude upgrade
nano /etc/locale.gen
aptitude install screen vim ntp
vim /etc/screenrc
vim /etc/fstab

Redmine from wheezy-backports, autocreate repos and access control

I had some trouble getting Redmine with subversion installed on debian wheezy. The main problem was the outdated version in the default repositories. I decided to use wheezy-backports repo to get a fresh but reliable version installed.

I also wanted automatic repository creation and redmine usernames and passwords to control the access to the repositories. Below is the result.. 🙂

aptitude install mysql-server
aptitude -t wheezy-backports install redmine redmine-mysql
aptitude -t wheezy-backports install apache2 libapache2-mod-passenger
ln -s /usr/share/redmine/public /var/www/redmine
vim /etc/apache2/mods-available/passenger.conf
PassengerDefaultUser www-data
a2enmod passenger
vim /etc/apache2/sites-available/default
<Directory /var/www/redmine>
RailsBaseURI /redmine
PassengerResolveSymlinksInDocumentRoot on
a2enmod passenger
/etc/init.d/apache2 restart

after login

ln -s /var/cache/redmine/default/plugin_assets /usr/share/redmine/public/
aptitude install subversion libapache2-svn libapache-dbi-perl libapache2-mod-perl2 libdbd-mysql-perl libauthen-simple-ldap-perl ruby-dev make
mkdir /var/svn
chown root:www-data /var/svn
chmod 0750 /var/svn
gem install activeresource
ln -s /usr/share/redmine/extra/svn/ /usr/lib/perl5/Apache
vim /etc/apache2/mods-available/dav_svn.conf
   PerlLoadModule Apache::Redmine
   <Location /svn>
     DAV svn
     SVNParentPath "/var/svn"
     Order deny,allow
     Deny from all
     Satisfy any
     # If a client tries to svn update which involves updating many files,
     # the update request might result in an error Server sent unexpected
     # return value (413 Request  Entity Too Large) in response to REPORT
     # request,because the size of the update request exceeds the limit
     # allowed by the server. You can avoid this error by disabling the
     # request size limit by adding the line LimitXMLRequestBody 0
     # between the <Location...> and </Location> lines.
     LimitXMLRequestBody 0
     # Only check Authentication for root path, nor again for recursive
     # folder.
     # Redmine core does only permit access on repository level, so this
     # doesn't hurt security. On the other hand it does boost performance
     # a lot!
     SVNPathAuthz off
     PerlAccessHandler Apache::Authn::Redmine::access_handler
     PerlAuthenHandler Apache::Authn::Redmine::authen_handler
     AuthType Basic
     AuthName "Redmine SVN Repository"
     AuthUserFile /dev/null
     #read-only access
        Require valid-user
        Allow from SERVER_IP
        # Allow from another-ip
        Satisfy any
     # write access
       Require valid-user
     ## for mysql
     RedmineDSN "DBI:mysql:database=redmine_default;host=localhost"
     ## for postgres
     # RedmineDSN "DBI:Pg:dbname=databasename;host=my.db.server"
     ## for SQLite3
     # RedmineDSN "DBI:SQLite:dbname=database.db"
     RedmineDbUser "redmine_default"
     RedmineDbPass "PASSWORD"
a2enmod dav_svn

Add to cron:

* * * * * root ruby /usr/share/redmine/extra/svn/reposman.rb --redmine --svn-dir /var/svn --owner www-data --url http://my.svn.server/svn/ --key=my_api_key >> /var/log/reposman.log