Posts

Showing posts from February, 2008

OpenDNS Fritzbox Howto

While I did some research on how getting this to work I saw many people trying this without success. Here is the definitive guide on how you use OpenDNS with your Fritzbox:
Make sure your firmware is up-to-dateEnable telnet
Login over telnet and type "cd /var/flash/", "nvi ar7.cfg"Search for overwritedns1 and overwritedns2 (they appear two times each) using the "/" key and "n" (next search result).
Press "i" to get into edit mode and enter the opendns server as noted in the opendns linux guideESC brings you back to command mode. ":w" saves the file and ":q" closes the editor again.type "reboot" to restart the fritzboxRestart you networking and you browser. The OpenDNS Site now should tell you that you are using OpenDNS already. Now you can create an account, set it to dynamic DNS, add network and login to dnsomatic.Now login to fritz.box using your browser and enter the following dynamic DNS settings: Update …

Workshop Project: Hot Wire Anemometer

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I just want to present my project I built as an own project in the electronics workshop hold at my university, that really has been quite interesting. Its a so called "Hot Wire Anemometer" (Airflow-meter).
Here you have the explanation as an excerpt of the project documentation:
Die Idee beim Hitzdrahtanemometer ist den Wärmeverlust an einem Glühfaden zu bestimmen und dadurch auf die Geschwindigkeit des kühlenden Luftstroms zu schließen. Um den Wärmeverlust messen zu können wird die Widerstand – Temperatur Abhängigkeit des Glühdraht benutzt um diesen auf einer konstanten Temperatur also Widerstand zu halten. Schließlich wird der dazu notwendige Strom, bzw der Spannungsabfall am Glühdraht gemessen, verstärkt und ausgewertet. Although we had a bunch of problems in the end everything worked very well and was a nice combination on analog and digital elements. As a hot wire we used a 6V light bulb where we took off the glass.