l i k a . b e

Category: Electronics

  • Search for text in files on Linux

    Searching for a certain text in mulitple files? Just run: grep -lir “word” * And you’re all set. It will return you the name of the files containing “word” in the current folders and subfolders. E.g.: ~/projects/xap $ grep -lir “header” * hub.c If you then need the lines that contain the search term, just…

  • Recovering from a RAID ‘Degraded Array’ event

    OK, so you have that nice and shiny server up and running with a RAID array, and all of a sudden you start getting ‘Degraded Array’ messages… Assuming the error is not hardware-related (i.e. one drive of the array that is failing) you can easily recover from this message.

  • Tracing a signal in ModelSim

    To log a specific signal in a ModelSim simulation, make  a script like this:

  • Adding MGE UPS support to SME server

    MGE UPS support Enable the monitor service config set nut service status enabled config setprop nut Model mge-shut config setprop nut Device /dev/ttyS0 signal-event post-upgrade /etc/init.d/ups start Verify if the UPS was detected upsc ups@localhost | grep mfr should show something like ups.mfr: MGE UPS SYSTEMS

  • Ethernet connected PIC: the NetNode

    I’ve designed a circuit with a PIC that has ethernet connectivity. The plan is to use this as a basis for a home automation system. Prototype boards have been running for over a year now to monitor our ventilation system and our solar heating installation.

  • Making a fresh install of a NSLU2 (SLUG)

    OK, it’s time to reinstall my Linksys NSLU2 NAS device (petnamed ‘slug’) to finally put it into ‘production’. This is a list of steps that I have taken, together with some notes that might come in handy if I ever need to do this again.

  • Installing RRDtool with perl bindings on the NSLU

    RRDtool is a nifty database mechanism that is widely used for monitoring parameters of routers, switches, weather stations, solar installations, … I use it to monitor various parameters of our home. Since this is a 24/7 task, I run it on a low-power devic: the NSLU2. This article describes how to install the RRDtools on…

  • Adding the smartd service to SME server

    It is interesting to monitor the hard drives of your Linux server for possible problems. The smartd package allows you to monitor the SMART parameters of any drive attached to your system. In case things are going wrong, smartd will warn you by email and chances are that you will be able to gracefully shut…

  • DCF controlled time switch

    I needed a way to automatically control the main heating of my parents house. The basic idea is to start the heating at a certain time in the morning, and to switch it off at night. The switching points are different on various weekdays. Of course, I could have bought a time switch. However, those…

  • WRT54G and the Dynamic IP services of BNamed.net

    BNamed.net offers a dynamic IP service as a part of their domain name registration services. They offer client software for updating your IP address, but the provided script requires some changes in order to work on your WRT54G(S). Below, you can a modified script for the Linksys WRT54G that updates your registered IP address when…