login: root

Month: February 2014

  • Power OFF and ON USB device in linux (ubuntu)

    Power OFF and ON USB device in linux (ubuntu)

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    nsc
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    There are two methods of doing this. So first method is for kernels after 2.6.32, and second for older ones. To view kernel version, simply enter: > uname -r 3.8.0-29-generic   find Your USB device, no mather what it is USB flash drive, Yubikey, USB disk drive: > lsusb Bus 001 Device 002: ID 8087:0024…

  • Squirrelmail hangs forever (DNS cache problem)

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    nsc
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    Noticed that one squirrelmail sometime hangs. It contained default directadmin installation configs. Straced proccess, and found that it queries DNS servers for a quite long time (only snippet):

  • MX backup server with postfix on debian

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    nsc
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    Not to lose mails when main mail server is down, best solution is – mx backup server. This is configuration to have backup mx server set up and running. myhostname = mx2.loginroot.com mynetworks = 127.0.0.0/8 maximal_queue_lifetime = 120d smtpd_banner = $myhostname ESMTP relay_domains = hash:/etc/postfix/relaydomains transport_maps = hash:/etc/postfix/transportmaps smtpd_recipient_restrictions = permit_mynetworks, reject_unauth_destination

  • RC car steering solution?

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    nsc
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    One solution came in mind for RC car steering. Control servo (planned or RC car steering) with potentiometer. Testing setup is very simple. Servo setup: +, – and control pin. Same as here: Simple servo setup Potentiometer will work as voltage divider. Here is more info about it: Voltage divider.

  • New project idea – RC car

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    nsc
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    One day thought that would be nice to make a RC car controlled with arduino. Unfortunately I don’t know how make such hardware, I needed to to find any car, that has possibility to turn front wheels to both sides. After few days of searching (all of them were expensive or front wheels were “fixed”…

  • Arduino + servo simple setup

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    nsc
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    Using servo with arduino is pretty easy. Here is my setup:

  • Exim mail via different IP

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    nsc
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    In /etc/exim.conf You need to change: remote_smtp: driver = smtp to remote_smtp: driver = smtp interface = 11.22.33.44

  • CP2102 + Arduino pro mini HOW TO

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    nsc
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    One day I noticed, that arduino pro mini are quite cheap for everyday stuff. It’s very small, and to keep lower price, this Arduino does not have USB interface. On ebay it’s ~3$: