Powerline is a technology for transmitting data over the AC grid. All devices provide an RJ45 Ethernet plug (and some also wifi and USB), so they support client devices of all operating systems. Basic configuration of encryption is likewise OS independent, as nearly all of them use a "pairing" button for that. However, to set the encryption key manually, to make more detailed settings, to read out speed statistics and to update the firmware most come with configuration tools that only work under Windows.

So, can we find a device that can be fully managed under Linux, ideally with free software? After a long search, this turns out to be a simple task. Just use any device that supports the Homeplug AV or Homeplug AV2 standard, and manage it with Open PLC Utils, a free software full-featured management tool developed by AV/AV2 chipset maker Atheros. It  allows full device configuration, info reading and upgrading for all INT6000/6300/6400/AR7420 devices, even tampering with the parameter set in the firmware. The only alternative are DS2 chipset based devices, since at least most of them can be fully configured via a built-in web interface (such as the COMTREND Powergrid 9020, their most modern device). However, a tool like Open PLC Utils is preferred here since it effectively replaces a part of the DS2 management software with free software, allowing scripting, modifications etc., and is more powerful in general.

Recommendable devices

It is said that it does not matter so much in terms of connection speed and quality which exact device you choose, as long as you choose the right chipse. Here, we focus on the Homeplug AV chipsets (INT6000, INT6300, INT6400) and there on the most modern one (INT6400). We avoid the Homeplug AV2 chipsets because they seem not yet mature (see below) and the DS2 chipsets because they are not as readily configurable under Linux.

Recommendation for Germany: Speedport Powerline 100. The best recommendation is so far: Telekom Speedport Powerline 100. It has the INT6400 chipset (most modern one for the Homeplug AV 200 Mbit/s devices), and it is dirt cheap (ca. 20 EUR incl. shipment for a pair of them, via ebay.de) because Telekom made Germany awash with these devices. It also is good quality, since it is a whitelabel product from well-known French brand LEA Networks – see also the very detailed test on tomsnetworking.de (in German). One can use the LEA-made software tool SOFTPLUG for settings beyond simple pairing for encryption, but it runs only under Windows. It is not needed however, as the free software tool Open PLC Utils can likewise be used, also running under Linux.

Discussion of alternatives: Devolo dLAN AVsmart+. These devices are quite nice, as they have an extended status display on the device – compare the manual. They are also readil available in used condition on eBay, but not as dirt cheap as the Speedport Powerline 100. However, they use the older INT6000 chipset [source], leading to a third less speed in long-range applications [source].

Discussion of alternatiives: COMTREND PowerGrid 9020. This is not a Homeplug AB/AV2 device, but uses the non-interoperable DS2 chipset. Reviews on Amazon are good. However, it can be fully managed under Linux as all settings are available within a web interface, as argued for and against above. The Powergrid 9020 is the most modern Powerline device of Madrid-based manufacturer COMTREND so far, and avaible in UK and Europe type plug versions. The UK plug versions are very readily available online, as they are provided by UK based large ISP Britich Telecom (BT) to their customers. The Europe plug versions are quite hard to find though (but here are some). Also see the installation guide and the  full manual.

Discussion of alternatives: Homeplug AV2 devices. There are the even more modern 500 Mbit/s Homeplug AV2 devices (using the AR7420 etc. chipsets), however as of 2014-09 this generation of technology seems to not be mature still, often suffering from connection breakdowns, low throughput, the devices running hot etc. (as judged from reviews on Amazon). So we avoid them here, also because they are still more expensive on the second-hand market. But your priorities and mileage may vary. They also can be fully managed with Open PLC Utils.

Linux software for powerline adapters

While Open PLC Utils is clearly the winner, the following list is all the Linux-based powerline software I came across:

  • Open PLC Utils. As said, clearly the winner: full-featured and free software.
  • Faifa. A manufacturer independent, free software Homeplug AV/AV2 utility for Linux. Allows low-level functions such as control frame dumps. Considered to be the successor to the older plconfig utility, see below.
  • plconfig. An older, simple Linux based configuration utility. For download on Github. Superseded by Faifa now.
  • dlanlist, dlanpasswd. Open source software that can be downloaded and compiled under Linux and is meant to list (and set the password of) Devolo dLAN devices. Since these conform to the Homeplug AV/AV2 standard, the software might be used to also configure other devices, after some simple modifications.
  • devolo Cockpit. A large configuration softwre for Devolo dLAN devices. Seemingly not available as a source version, so adaptations to other devices are not possible.
  • Intellon device manager for 3.x firmware (Windows software). Allows full management of INT6x00 chipset devices when using a 3.x firmware version, incl. editing firmware parameters. Its use is described in this article.
  • Intellon device manager for 4.x firmware (Windows software). In contrast to the version for 3.x firmwares, this does not support full management of the of INT6x00 chipset devices any more.

Background information

The following in-depth articles provide relevant background information about Powerline technology and their successful use:

Modding and hacking powerline adapters

At 10 EUR for a used device or less, powerline adapters are so cheap that they offer themselves to several non-standard uses. At least teh following come to mind:

  • Powerline noise filters. Devices that include an AC plug with noise filter (such as the SpeedportPowerline 100 recommended above) are the cheapest option to use them as frequency filters to prevent contamination of the 50 Hz frequency from other digital devices, mobile phone chargers etc..
  • Powerline bridge. It is also possible to create a simple bridge by connecting two of them with a crossover Cat5e cable (or a bridge device in between, if necessary). This should allow crossing phase boundaries in the home cabling, if necessary.
  • VDSL P2P modem replacements. And then, of course, these cheap devices are a natural candidate for creating a cheap DIY replacement for pairs of VDSL modems (usually 150 EUR per piece!). It works by connecting twisted phone wire to the signal (via soldering) before it gets modulated on the AC mains power. It is possible to use this for transmitting data over several hundred meters at least.

 

This applies for example when you want to add a photovoltaics installation to your campervan, expedition vehicle, garden hut, off-grid house or similar. For having enough electricity year-round from photovoltaics alone, battery size and module size have to be properly dimensioned.

The best tool I found for this is the European Commission JRC's PV potential estimation utility. There, use the last tab "Stand-alone PV".

Note that that the tilting angle of the solar panels is important in winter. Differences of up to ca. 30° from the optimum have no large effect, but above that they get quite important. So having an angle of 0° (flat panels) while you should have an angle of 74° (Germany in winter for example) means you get only about 25% of the power you would get at a 74° angle. You can calculate the exact numbers for this with the SunAngle calculator.

Statistical Design Meeting and Workshop in Strasbourg, 2013-03-25 to -26.

We worked quite intensively and at the same time, everybody seemed to enjoy it – that's how I like work to be 🙂 Thanks to everybody involved!

All images on this page licenced under CC BY-SA 3.0 Unported, or at your option, any later version.
Please attribute to "Matt" and this page's URL (that is, do not use my real name).

Sorry for the bad image quality. My real cam broke down and I did not get around yet to repair it …

On a nice evening with a friend in Málaga this October, we developed this idea for political street art. (We were kinda oversugared from the best icecream in town … it explains something, doesn’t it? 😀 ) Initially we wanted to cut our own “Espere Revolución” signs and install them over the city’s normal push-button boxes for pedestrian traffic lights. But for now, it’s a mockup.

Political street art: Espere Revolución (small excerpt size 1024×768)

Political street art: Espere Revolución (large size 2048×1365)

The pedestrian traffic lights sign in the image reads: “Touch the button”. Then you push it, and it says then: “Expect revolution.” (It’s normally “Espere Verde” – expect green light. Plus a standing person with both hands down.)

Licence: Creative Commons Attribution Non-Commercial Share Alike 2.0

Credits: The original image was created by flickr.com user david buedo and published as flickr image 6949945397 under a Creative Commons Attribution Non-Commercial Share Alike 2.0 licence. Thank you!

Modifiable version: Just tell me in the comments if somebody wants the GIMP .xcf.bz2 file of this, with layers for easy modification to make other signs as well.

It seems like this:

  • The lashing capacity LC according to the norm (EN 12195-2) means the maximum allowed force on the strap in straight pull.
  • When buying lashing straps, you might get an additional second LC measure that is double of the normal LC. This is the lashing capacity in round pull.
  • Why is round pull LC double that of straight pull LC? Think of an application where you connect two points have 180° deflection of the lashing strap (around a tube or similar) at each, in effect making the lashing strap go a full round. A model for this is a small set of pulleys with two barrels and double string. Each of the strings of the one lashing strap (one going forward, the other going back) now has only to bear half of the force between these two points that you pull together, which doubles the lashing capacity compared to straight pull. And as in a pulley system, the force on the belt is the same everywhere as it can distribute evenly, so the part in the 180° deflection point also bears just half the load of the full system.
  • To make the confusion complete, there is a code concerning straight line seams on the lashing straps. They are called “ton lines” (German: Tonnenstreifen) and people think that they indicate: one stripe per 1000 daN lashing capacity in round pull (not in straight pull). But I have yet to see the norm text for that and could not find any source (Hey regulators! You still don’t have these as open content? C’m on, nobody wants to pay 224 USD for the EN 12195-2). In case of lifting loops, they are called “load bearing capacity stripes” (German: Tragfähigkeitsstreifen) and there, indeed, one stripe seems to mean 1000 kg of capacity, but in direct pull.

See also another (German) site with explanations of the lashing strap norm’s abbreviations (LC, HF, SHF, STF, BF, BFmin).

Before using information in this text for security critical applications, check the facts for yourself. I do not take any responsibility!

Currently I'm building the first parts of my truck's furniture system. The system is based on gridbeam, an awesome simple DIY construction system from the 1970's. Practically this means: boxes, room partitioning walls, shelves, desks etc. all use the same sheet material and connector elements and with the same compatible hole pattern, so one can build everything from the same set of elements, and can reuse the parts from a no longer needed object to build something else. Or reconfigure the furniture according to current demands, using an inbus wrench.

I'm starting to build my furniture with some simple storage boxes that will be secured to the wall in several layers, yielding a big 70 cm deep shelf for general storage. Both this box system and gridbeam itself are detailed in the interface specs part of the EarthOS document. But here's a quick overview of my design choices:

  • Compatible with ISO pallets. Size is 700 x 350 x 350 mm, together with with handles and corner elements etc. up to 800 x 400 x 400 mm is allowed.
  • Same size walls. The basic wall size is 350 x 350 mm, and in this case I build double-depth boxes, so some walls are 700 x 350 mm. These larger walls could also be created by combining two of the smaller walls with aluminum sheet metal connectors; and likewise for even larger boxes. To allow creating a box from just same-sized walls, the walls have 45°  beveled edges.
  • 50 mm gridbeam system. This means, all sheet material has a 50 x 50 mm hole pattern starting 25 mm from all edges (holes are here only around the edges, more holes can be added on demand). Holes in boards are 8.5 mm for M8 bolts, but in the case of boxes fitting for M6 sleeve nuts. Holes in aluminum connector elements are 6.5 mm for M6 bolts.
  • Modified hammer-in nuts. I really had a problem finding reasonably priced sleeve nuts for going into the board holes – I'm just not paying 1 EUR and more for one lathed sleeve nut, that would be 55 EUR per box for 'em alone. So I finally tried ordinary M6x8 hammer-in nuts with their four spikes, and just cut away the spikes with tinsnips. By letting 1 mm of the spikes in place, these nuts will not even free-rotate when at the loose end and turning a bolt into them. They have enough grip in wood that way, while the sheet wood and the nut is still reusable infinitely (which was not the case with the spikes in place).
  • Bolts used. Currently M6 x 13 stainless steel (A2-70) bolts with inbus head. Used together with a washer to secure the bolt against loosing and to better distribute the force to the (relatively soft) aluminium sheet metal.
  • Apt for cheap and salvage materials. I'm currently creating the corner elements from simple aluminum sheet metal that I had lying around and that can be had from the local recycling yard nearly for free (as in free beer, not as in FREE BEER). Using 50 x 50 mm and 100 x 50 mm aluminum L-profile is also possible and looks better (examples in second picture) but is of course more expensive and less autarkic. Also, one can use many different types of material for the box walls: any thickness will fit because of the beveled edges and because the box's outer measures are standardized, not the inner ones.

Writing this I realize how trivially simple this design is. Yet the simple ones are hard, for whatever reason. I had developed thoughts for the box system over months, and even started building one variant which was way too complex and too expensive. The current variant emerged after some great, inspiring discussions with my Dad on the matter. (I should know where my hacker genes come from ;))

And here are some pictures of the current progress with the boxes. (Some parts are obviously still missing: corner elements for stacking, handles, a flap, locking bolts.)

See this unrelated item in the media gallery? It's a rare Thermoflash fluid-heated jacket that I got as a bargain on eBay. Can keep everybody warm through German winter. Yep, really everybody 😉 Normally used on motorbikes and connected to the engine's cooling circuit via a heat exchanger and digital temperature control.

Oops, no wheels :) But we're checking the brakes.

Here’s a little page with images and videos from the make-a-truck-my-home project that I have going on since … well, too long already 🙂 Enjoy!

A video of the raw box body the morning after we transported it home:

And a video of driving the truck to the petrol station immediately after buying it: