User Tools

Site Tools

TAG: research

Active Wideband Receiver Antenna for your SDR

Software Defined Radio (SDR) has finally reached a much broader mass of people, who wanted to play with RF technology, but didn't find the time or resources to learn all necessary skills, to build a hardware based radio. Thanks to the work of the GNU-Radio and OsmoCom developer crowd, this barrier is finally gone and everyone can, more or less, directly access, what the antenna receives.

Apollo, we have a problem...

Another Hackathon-Weekend passed by and the DSpace-Client and its backends are really shaping up nicely. A lot of code was refactored during the weekend, taking full advantage of amd, backbone and ender now. The first real-time data sharing overlay was tested successfully as well, so we managed to get a lot of the basic features we imagine to have in DSpace working.


This is an early draft proposal for a solid, modular and distributed communication/monitoring system shared and operated by communities (not everyone needs his own equipment in a neighboring area). It will offer services locally for community members and the nodes should be interconnected worldwide to create a global network of free-to-access Communication- & Monitoring-Nodes (CMN).

Blu-Ray nanopatterns to boost solar (PV) efficiency

There are often reports about breakthroughs in alternative technologies and when I look, I can find charts claiming that in 2014/2015 top solar conversion efficiency is reported to be at about 45%. However, when I look harder I don't seem to find obtainable Panels above 21%. The highest grade I could get were the Mobile Technology MT-ST110 panels on the Odyssey (Command-Module). I can't help but to ask myself:

BX48 Prommer generously provided by Batronix GmbH

The new Batronix BX48 Batego is an extremely powerful, compact and easy to use universal programmer, that also comes with Linux support. After 3 failed attempts with different Galep-Prommers to write an eprom, Andre Bauer, managing director of Batronix, was kind enough to sponsor one of these nifty devices for Apollo-NG's R&D Lab. Thanks a million, Andre!


DSpace aims to enable people to find, collect, edit, structure and share any kind of information in a real-time, massive-collaboration, augmented-reality-environment (like wikipedia), based on a very common ground: The map of the area, where people actually are, around their Geolocation.

DSpace Bootstrapping Day1

Today we managed to test the local providers, tile rendering, tile delivery and successfully consolidated the options for the next steps. We still have one seat failing on us, but it's good to know, that we all can buckle our seat-belts. It's been great fun, as always :)

DSpace Bootstrapping Day2

With more manpower and additional resources we've managed to finish refactoring the initial mockup client code to use the ender javascript “package manager” and decided to go with qwery, bean, bonzo, underscore, backbone, handlebars and domready instead of a fully bloated js framework like jquery or extjs.

DSpace Bootstrapping Hackparty Ended

3 nights and two days of hacking have come to a very successful end. It was a great experience, none of us ever participated in a hackparty/hackathon so we really didn't know how to go about it. On Friday we tried to establish a common ground and basic guidelines where to go and what to do, on Saturday we were all over the place and we mostly refined the way we are going to handle the repos and from Sunday morning we really digged into it. At this point I really want to personally thank all peop…

DSpace Development

After the fruitful session on the weekend, we used the opportunity of still being together in Munich to scheme up the new internal structure and models/views: Changes in the develop branch to follow the new model are already underway and DSpace is now an official Apollo-NG R&D project, so everything will start moving into the DSpace namespace from now on.

DSpace Development Updates

After the last collaborative hacking session on DSpace, the client developed and changed a lot. We've already integrated automated testing, using phantomjs and travis, the primary git repo changed from Apollo to github, in order to facilitate Pull-Requests and combined issue tracking. From now on, please don't push DSpace stuff to the Apollo-NG Repo's but use the github repo's as your origin. Every push to develop branch on github is automatically synced to the Apollo-NG repo and then automagica…

DSpace Progress

A lot is happening and a a few more people have started to contribute their time, skills and knowledge to push DSpace into the realm of reality. Last Saturday, Niklas Cathor, also a strong supporter of federated technology, dropped by and joined the hackparty to just start hacking on moving us to amd.

Elonics E4000 complete reference documents leaked

Good news for anyone playing and developing cheap SDR technology with the Elonics E4000 (e4k) tuner chip: Until now, working with the chip has mostly been guesswork and trial and error through reverse engineering, in order to get the SDR's to work. Today the complete Elonics E4000 reference documentation was leaked, so grab and mirror the e4k datasheets and application notes, while they are hot and available:

External-Antenna Hack for TP-Link TL-MR3020

Hacking devices always comes with the risk of breaking them in the process, which makes it often undesirable to hack on something, when you know, that you only have one device you may need for production purposes. Luckily, cosmo had a look at the Apollo-NG Wishlist and donated one more TL-MR3020 for the cause and as a result, it was pretty easy to figure out how to connect an external antenna to the TL-MR3020.

EZVD - Easy Voltage-Divider Calc-/Simulator

[EZVD Output on the console (python/ncurses)] If you want to learn more about voltage-dividers or need a tool to design/verify voltage-divider resistor selection for your next electronic engineering project, try EZVD - Easy Voltage-Divider Calc-/Simulator

EZVD - Easy Voltage-Divider Calc-/Simulator

When you migrate from just learning by copying open-source hardware designs/schematics towards creating your own electronic designs and solutions, you'll sooner or later will be confronted with the task of designing and selecting the right resistors for a certain voltage divider.


* Multi-Stacking Modules * Build a common model for generator scaling according to rotor size * The generator module should always be at the bottom of the mast, reducing the top load of the mast and also making the generator more accessible for maintenance.

GPS Modules & DevKits generously provided by uBlox

Even the earliest Apollo-NG design drafts already included multiple GPS dependencies for a number of subsystems. Apart from obvious navigation assistance, GPS will also discipline the reference clock module and the 10MHz reference oscillator module GPSDO. The first prototype was hacked around an old Rockwell/Connexant Jupiter TU30-420-031 GPS receiver, found on eBay.

Hacking RF controlled power switches with HackRF

In order to learn more about GNU Radio and HackRF, so that tackling more complex scenarios like The DARC side of Munich become easier, it was time to go for a much simpler training target: Those cheap RF controlled wall plugs you can use to remote control the power outlets. Now, I'm not talking about FS20, x10 or HomeMatic devices but the really cheap ones you can usually buy in sets of three combined with a handheld remote controller for 10-20 EUR.


The goal of this project is to develop a robust, versatile and resource-effective biomass micro-gasifier by combining a controlled-draft TLUD (Top-Lit Up-Draft) gasifier with an array of TEGs (Thermo Electric Generators) and a microcontroller to optimize the gasification process.

Intelligent Turn Signal

While watching some fast cars on a multi-lane street from above today, one observation came up with repetition: Fast movers, that wanted to overtake slow movers (on the right line) almost never used their turn signal (blinker) to indicate their intention to move to the left lane and afterwards to move back to the right lane. Why is that and how could that be helped?

Learning to build a simple metric scraper robot

I know that we usually fly over webpages just scanning text for keywords and structural bits and pieces of information, with the least amount of attention we can spare. We often don't really read anymore. But today I would like you to slow down, take a moment, get your favorite beverage and sit down to actually read this, because a part of my current work presented a perfect opportunity to go into learning, knowledge transfer, inspiration and of course the misconception of originality as well.


Standard-Parameters Maximum assembly height The complete assembly of rotor and mast should not be higher than 10 m. If regional communities permit higher masts, the maximum height must not exceed 20m, to avoid national and ICAO air traffic security issues and legal obligations to carry warning lights and report about their functionality.

More PiGI Geiger counter modules in the Wild

It's truly awesome to see how the PiGI - Raspberry Pi Geiger-Müller Interface, born under ghetto-style conditions with zero prior knowledge or budget, has not only spread to hackers and other individuals with a sense of independence and prudence worldwide, but was now adopted by a special working group of Computer Professionals for Peace and Social Responsibility (FIfF) called Tihange-Doel Radiation Monitoring Network.

More PiGI PCBs available

If you've missed the opportunity to get a PiGI PCB of the first batch, here's your next chance to turn your Raspberry PI into a versatile Geiger-Counter. All hail Fehlfarbe. pigi geiger pi raspberry hardware radiation monitoring research development

More PiGI prototype boards finished

Last Saturday, instead of breakfast, we wanted to have more geiger counters. So we had an early morning soldering session in the open air and with plenty of sunshine we finished two more 1.0 prototype boards so that we have more active PiGI's for tests and further development.

NFM GNU-Radio Receiver for RTL/OsmoSDR

Soon after the release of RTL-SDR a lot of people started to play with software defined radios. Although the Elonics E4000 tuner and the Realtek RTL2832U Chip are a long way from the quality and performance/stability of an USRP(2), the price of $11 - EUR30 makes these devices an ideal beginners device for SDR experiments, without having to invest +$1k into hardware.

Personal Log: Digital Exorcism

When you leave the commercial/proprietary software ecosphere and jump into open-source operating systems, you will have to learn how to handle daemons. And once you've created a couple of those daemons yourself, taught them what to do and let them work in production, you gain a lot of experience and confidence in dealing with all kinds of daemons.

Personal Log: PiGI Testing

Some time ago i stumbled upon the PiGI project, joined the chatroom and somehow convinced chrono to send me a prototype board. Thanks for that! So here will be a summary of my testing of the PiGI. The Geiger-Mueller-Tube I bought an old russian SBM-20 tube on ebay for 26$ and soldered some cable to both ends and isolated the ends with heat-shrink tubing. Then i soldered it to my PiGI with some leads that I thougt had sufficient isolation for high voltages.

picoCNC - A modular fabrication robot

Hackerspaces, FabLabs and Open-Eco-Villages need tools to bootstrap their own individual environments. Although RepRaps, Makerbots and Lasercutters are more common these days, many groups are still lacking CNC routers/mills to create really solid tools or parts for bigger machines. Maybe some of the solutions presented here will inspire other groups, to build more CNC machines and extend our ability to make stuff on our own and for each other, by sharing plans how to build machines and plans for…


Heavily modded proxxon tool and stand. [picodrill-complete-with-proxxon-tools-and-footswitch] * removed all regulators from the Proxxon Tools * added RF suppression caps to the tools (standard 3 cap triangle config) * added microcontroller to control rpms via pwm to enhance low rpm torque * added three LED's for drill area lighting * added quickconnector system, tools connect their cable directly to the stand * added foot-switch that smoothly ramps up/down the drill to save power …


Building a spray etching machine, enabling the lab to fabricate double-sided pcbs. Focus on minimizing: machine area, energy consumption, volume of hazardous materials. In the end, etching pcb's should be fully automated. Design Considerations * Capacity: 2x 160x100mm (2 Eurocard PCBs) double sided * Etching Fluid Volume: 750ml (Sodium Persulfate) * Heating Element: Resistor-Wire embedded into silicone (90-135W) * VCC: 12-14V * Controller: Atmega88 * Temperature Sensor: Dallas DS18…


More and more semiconductors are produced in packages (the chip's case) which have become impossible to hand solder with a solder iron. The switch from through-hole (THT) to surface mount technology (SMT) has actually made hand soldering much easier (although still many believe the opposite to be true) but now we are faced with BGA and other packaging forms which only have contacts on the bottom of the chip.


The picoUVX is a highly efficient, mobile 10W UV-Exposer unit, based on modern LED technology and a very efficient, yet simple step-up switch mode supply design, with a low conversion loss of about 7% (93% efficiency). It's the first member of the picoFab family, to make off-grid development of fine pitch PCB's possible anywhere, using just 12VDC/0.83A (10W).

PiGI Software Hacking & Hackathon

For the last couple of days we've been really busy pushing the pyGI/webGI software suite that goes alongside the PiGI to make it a really useful geiger counter and we're very proud and happy to show you some of our preliminary results. Our goal was simple: Build the most cost-effective, non-profit, open-source geiger counter and offer more features with an easy to use interface than any other commercially available solution. Even now in the early states we already have achieved that goal.

Project Release: PiGI Module

Thanks to Maximilian Batz from <>, who sponsored two Raspberry Pi B models for the cause of Apollo-NG, it was time to see what more could be done with them. This essentially forked two subprojects: * Raspberry Pi based autonomous Antenna Tracker (following a MAVLink enabled UAV/Drone) * Raspberry Pi based geiger-counter

Project Release: UCSSPM

The Unified Clear-Sky Solar output Prediction Model is an open-source clear-sky prediction model, incorporating math algorithms based on latest research by the Environmental and Water Resources Institute of the American Society of Civil Engineers and a few veteran but still valid and publicly available NOAA/NASA computations. It has been around for a while but received a major revision, code refactoring and got bumped to primary project status, since it's becoming an essential tool in predicting…


Compared to drag-only type rotors (Savonius), lift-only type rotors (Darrieus) have been proven to be generally less suitable for low wind environments since they're difficult to start up. The maximum speed of drag-only type rotors is always lower than a comparable lift-only type rotor, because a lift-only type rotor can rotate faster than the wind speed at the tips but with less torque. However, the Gorlov rotor with a NACA 0015 airfoil may be a very well suited lift-type rotor for small-scale,…

SEEDStack - Open 3D printable seed/sprout system

Food Hacker? Low on Kitchen estate? Small Budget? Mobile/Ghetto Kitchen? A nomadic Hacker in need of protein rich and vitamin packed food supplement with a very low weight/volume footprint in your backpack, which you can grow on-site? Afraid of the Zombie apocalypse and thinking about solutions for supply needs similar to the nomadic hacker's? Want to personally make a change and stop/reduce eating out-of-local-season import fruit, which would otherwise have to travel up to 12.000 km to get to y…

SEEDStack - Open 3D printable seed/sprout system

Food Hacker? Low on Kitchen estate? Small Budget? Mobile/Ghetto Kitchen? A nomadic Hacker in need of protein rich and vitamin packed food supplement with a very low weight/volume footprint in your backpack, which you can grow on-site? Afraid of the Zombie apocalypse and thinking about solutions for supply needs similar to the nomadic hacker's? Want to personally make a change and stop/reduce eating out-of-local-season import fruit, which would otherwise have to travel up to 12.000 km to get to y…

The DARC Knight rises

It seems like it's time to pre-warm our oscillators and prepare our SDRs for more DARC action in the near future. For more than the last 4 month, the traffic to The DARC side of Munich revealed an interesting pattern: There was a steady increase of traffic coming first from the big European & Asian automobile manufacturers, then from automotive subcontractors globally and now from Asian electronics manufacturers.

The DARC side of Munich

When you live in Munich and use public transportation, especially Buses and Trams, you will have noticed that during the last couple of month a lot of new displays appeared at almost any station which had no real-time info display before. They obviously have no cables/connections and no visible antennas, so I kept wondering:

The evolution of fire

Open Fire Stove Hobo/Rocket-Stove <> TLUD Natural Draft (ND) Forced Draft (FD) Controlled Draft (CD) energy helios research tlud biomass


The Tiny Vertical Axis Wind Turbine is a prototyping model for the Zephyr Wind-Park Construction Kit. Prototyping Gathering the material for the first prototypes. Do you have something available for this project? Please add yourself to this list and describe the parts, tools or experience you have to share.

UmTRX publicly released

The UmTRX is a dual-channel, wide-band SDR transceiver (so it can send & receive) with 1GbE connection. It is developed by Fairwaves team to be used as a transceiver for OpenBTS GSM base stations, but due to its software defined nature, it could be used for many other radio applications as well.

Unified Clear-Sky Solar output Prediction Model

Using the sun as a sustainable energy source isn't really a new invention. Plants have been relying on it for millions of years and have developed and optimized the process of photosynthesis over a very long bio-evolutionary period. Almost everybody appreciates the comfort, when it's warm and the sun is shining but we very often forget how hard our ability to actually survive as a species, is linked to solar output:

Watterott-Electronic sponsors Hardware

Buying Sparkfun products and being in europe always was a little bit annoying due to shipping times & customs hassle. Stephan Watterott, CEO of Watterott-Electronic, offers many sparkfun products and other greatly hackable devices and components in his Shop, shipped directly from Germany.


Megawatt scale HAWT grid-tie windparks are operating at optimum height in specific areas, with strong and mostly continuous winds. This makes their development, construction and maintenance very labor- and resource-intensive projects and causes much inflexibility in the process of finding a suitable location for deployment and operation.