a blog about projects, teaching, programming and other stuff

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Creating the safest ETH paper wallet with a Raspberry Pi

1.101

with a printer and without an internet connection


Accepting Ethereum payments without external services

1.334

You don't need to pay for merchant systems


DIY vertical hydroponic system

456

grow vegetables in small spaces


Making a simple Raspberry Pi Bitcoin/Ethereum trading bot

4.397

with rocket.chat and Slack status reporting


Is Guetzli useful in production?

728

It's much better than google promised - 51% smaller images


Finding bombs in the forest

452

treasure hunters make it easy to find them


How a scammer stole 500$ from me and in the end begged me not to tell his parents

161.470

Thank god not all scammers are professionals


Forget Pay2Win - the time has come for Learn2Win

3.594

how to reward players in any game for academic achievements


My door sends me chat messages

18.719

Raspberry Pi powered door sensor and Rocket.Chat bot with some neat info


DIY cloud lamp for fun and profit

2.607

ok, just for fun.. no profit involved


Letting students mod school computers

1.578

with some amazing results


How to visualize RADIUS connections

3.503

by parsing Windows Server log files


Raspberry Pi controlled power sockets

3.012

it's as easy as it sounds


My company just turned 10 and it was quite a ride

2.812

also: about the time Thomas Schranz and I almost invented Dropbox


That (not so) awesome time the police raided my home

27.949

lesson learned: Don't click on links random people send you


Water cooled NAS made from spare parts

3.455

with Macguyverish solutions for common problems


DIY: Cheap wall mounted, water cooled PC for 51$

23.044

with LED backlight and and all the good stuff


Let's analyze over twenty thousand proxies

2.881

It won't get much better


Analyzing 443 free proxies - Only 21% are not shady

29.497

what about the other 79%?


What would happen if you'd embed a remote JPEG with a HTTP link but the remote server is forcing HTTPS?

1.028


Neue Reifeprüfung analyzed

1.112

The simple way to get a good grade


Repairing a closed loop CPU water cooler with aquarium tubing

2.975

air bubbles... those f***ing air bubbles


Raspberry Pi 2 wireless temperature box

2.214

The π² + wifi + 1wire sensor = pure awesomeness


Chromebooks for Work & Classrooms

2.550

are they worth it?


Announcing: Socialcube LITE

1.339

My proof-of-concept evolved to a intuitive platform which is free for every educational institution


Why hackits are the first thing I teach new classes

2.978

they represent everything I love about computer science


My XP-based grading system

19.054

a modern approach to grading in the year 2014


Raspberry Pi controlled LEDs

12.554

to visualize the up-state of my servers


IKEA Server Rack

4.315

nope, not a lack rack


DIY hydroponic pot for ~36€

3.846

Easy to build and awesome for your plants


Temperature visualization

1.869

from 6 months of data


Raspberry Pi temperature monitor

3.915

with a nice graph and live updates


Why are free proxies free?

170.167

because it's an easy way to infect thousands of users and collect their data


My door sends me emails

10.207

Simple and cheap Raspberry Pi burglar alarm


HTML5 heat spreading simulation

1.375

with a simple JS algorithm


hackthissite.org ascii code picture challenge

1.602


PHP script that filters moods from twitter

993

..how depressed is the web?