Once you have set-up a web server like Apache or nginx running on the Raspberry Pi it is time to create a website. From here there a several options: A CMS that relies on a database, some purely manual crafted pages or a static pages generated by a script. I chose the latter for some reasons. Static sites have a lot of advantages: no database to slow requests down offer greater security, as they do not contain dynamic content, so are immune to the most common attacks flat, text files, makes them ideal to be used with version control systems, such as Git low footprint on the server as serving raw html files But there also some limitations:

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I have been using Munin to monitor the health of my Raspberry Pi for while now. As I have more devices installed in my network I was looking for a way to monitor these devices as well. As Munin uses a client-server model you are required to install the Munin node on the device to be monitored. Every five minutes the Munin server polls its clients for the values and creates charts using RRDTool.

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After collecting some photovoltaic data using PikoPy and a some readings from the residential meter it was time to put everything together. The data is collected by a couple of scripts triggered by a cronjob every five minutes. $ crontab -l */5 * * * * python /home/solarpi/kostal_piko.py */5 * * * * python /home/solarpi/collect_meter.py */15 * * * * python /home/solarpi/collect_weather.py The results are then written into a SQLite database.

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A friend of mine had a photovoltaic system (consisting of 14 solar panels) installed on his rooftop last year. As I was looking for another raspberry pi project I convinced him I would setup a reliable monitoring solution that will lead him to an access to the data in real-time data. The current setup comes with an inverter by the company Kostal. The Kostal Piko 5.5 runs an internal web server showing statistics like current power, daily energy, total energy plus specific information for each string.

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Two days ago the official hard-float Oracle Java 7 JDK has been announced on the official Raspberry Pi blog. Prior to this there was only the OpenJDK implementation which was lacking performance. Furterhmore the Raspberry Pi Foundation announced that future Raspbian images would ship with. Oracle Java by default. If you want to give it a spin you can install the JDK with: $ sudo apt-get update && sudo apt-get install oracle-java7-jdk

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If you work a lot on the command line you are probably familiar with the top utility to see what process is taking the most CPU or memory. There’s a similar utility called htop that is much more powerful. On top of the information that top provides, htop additionally shows your usage per CPU, as well as a meaningful text graph of your memory and swap usage right at the top.

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If you are overclocking your Raspberry Pi or you just curious how hot this little guy gets, there are two ways to get the internal temperature. Assuming you are running Raspbian as your operating system. Method 1: $ /opt/vc/bin/vcgencmd measure_temp This gives you the temperate in in degrees Celsius: temp=54.1'C Method 2: If you need the temperature to be more precise (e.g. storing it in an database or for further processing) use the following command:

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If you log into your Raspberry Pi using ssh it will prompt you for a password. Having to do this multiple times a days this is very annoying. To ease the pain, and enhance security, you can use public key authentication instead. Therefor you create a pair of keys on your client, and store the public key on your Raspberry Pi. Then you set up an authentication by key. Afterwards the user can login into the Raspberry Pi using his private key.

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**tl;dr Checkout the charts on my RaspberryPi ** For quite a long time I was looking for a way to monitor and record th temperature and humidity at my apartment. What was missing was a convenient, preferably wireless solution. After receiving my RaspberryPi I started to look into that more intensively. USB-WDE1 Receiver The USB Weather Data Receiver USB-WDE1 wirelessly receives data from various weather sensors of ELV at 868 MHz.

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Once you have set up your Raspberry Pi chances are that you want to access it from remote machine or host a little web site on it. The problem is that your provider usually gives you a dynamic IP, which changes every time you connect to the Internet. In Germany most (A|V)DSL provider reset your connection every 24h. The solution for this is a dynamic DNS (DDNS), which automatically updates the name server in the Domain Name System (DNS).

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Christian Stade-Schuldt

Data Engineer @ HERE IoT innovation lab| Full-time geek | Cyclist | Learning from data

Data Engineer @ HERE

Berlin, Germany