Tag Archives: featured

DIY MQTT smart plug with MicroPython…

I’ve been playing around with MicroPython and Home Assistant. MicroPython is a ‘bare-metal’-Python flavor that you can use to program ICs. Home Assistant is a home automation and home control software written in Python 3. It can be hosted on a Raspberry Pi. It enables you to connect a vast amount of different devices: lights, switches, sensors, locks etc.

This is a raw guide on how to make your own smart plug and connecting it to MQTT which is then connected to Home Assistant.

You will need a relay board (single relay), a NodeMCU board, a power adapter for 5V, a case, a button, some wire and a 1k resistor.

Connect the devices according to this schema (WARNING: Don’t do this if you’re not comfortable handling mains power!). Don’t forget earthing (it’s not on the diagram):
circuit diagram

Flash the MicroPython firmware to the NodeMCU board. Put the ‘relay_mqtt.py‘ file on it as main.py. That way it will be run when the device boots up. Adjust the code to connect to your network and MQTT server first.

You can download the code here.

My device looks like this:

See the Home Assistant documentation for how to integrate the MQTT part with Home Assistant.

The nice thing is: you can press the button to switch the device. The status of the device will update via MQTT and Home Assistant gets a correct status update. You can of course switch the device from within Home Assistant as well.

Happy hacking!

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Jabber via TOR…

The torproject just released ‘Tor Messenger‘. It’s an instant messaging application that allows you to communicate via XMPP (jabber) over the Tor network. It is based on Instantbird.

It is important to know that the client will mask from where you are connecting, but it will NOT mask who you are! This is due to the fact that your alias at the jabber server was probably created beforehand. And even if you create the alias with Tor Messenger, your connections to other users make it possible to identify you.

If you want to chat REALLY Continue reading Jabber via TOR…

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Cheap and Free SSL/TLS Certificates…

I recently was pointed to a website where one can get really cheap SSL certificates (Danke Oliver).
They sell certificates, signed by GeoTrust, Comodo, RapidSSL, Thawte and Symantec. As CheapSSLSecurity is a major reseller they can offer a really low price. If you take a 3 year certificate you get as low as 5$/year.

I am aware that there is an offer for FREE SSL Certificates out there. The drawback is however, that they are free to get, but cost 25$ to be revoked.

There are also efforts on the way to make encryption free and easy to use: Let’s Encrypt is a free and automated open-source certification authority. Their plan is to offer free certificates in summer 2015.
If you can wait for this service, it should be the cheapest option. To learn more about Let’s Encrypt, watch the talk that was given at 31c3 (icon-magnet magnet link).

And of course there is CAcert. They are a community driven assurer, which I’ve been using for many years. They however did not yet manage to be included in popular web browsers. Using their certificates will likely trigger warnings with normal desktop setups. Their certificates are free and depending on your involvement they grant certificates for up to two years.

Personally I’m using CAcert for most certificates, but whenever a broader audience should be able to connect without warnings these certificates become combersome. This blog is using a Comodo certificate via cheapsslsecurity.

Update 2015-01-03 14:00: added the Let’s Encrypt video from 31c3.

Update 2015-01-16 12:30: A user comment pointed at www.cheapsslshop.com, which seems even cheaper at $3.5/year, with a new years discount code (“CMDXMAS50”). Thanks.

Update 2016-02-04 07:30: Let’s Encrypt is issuing for a few weeks now, and they just issued their 500.000th certificate today.

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Lego Lamp

More than a year ago I came across a designer lego lamp. I really liked the idea but the price tag was a little hefty. Back then the lamp cost $800 and now it is at $995. But to be honest there is no designer product like this lego lamp that really says “do it yourself” like that!

So I built one myself. I designed the basic form with Lego Digital Designer. The plan can be found here [1]. The base of the lamp uses about 800 pieces. The final build varies from the my first plan, especially in the base where I first planned to hide the foot of the old Ikea lamp. I finally just used the lamps main rod and electrical wire. The arrangement of the bricks varies to give the lamp more structural integrity and was improvised.

The parts were ordered from three different shops on BrickLink. They offered the green I wanted for the lamp at a fraction of the price of the original Lego™ store. The total price for all parts was about 60€. The lamp I had laying around was ‘free’ and the new lamp shade was about 30€. Total of about 100€ – well below the price point of the original.

[1] 2014-11-22, 18:30:

I was asked by the designer Sean Kenney, to remove the LDD plans for the lamp. He argued that the plans would hinder his ability to sell these lamps online.

Although I do not agree with Sean’s argument, that his sales might be influenced by a simple Lego™ scetch for a similar lamp, I’ve respect for the work that went into the lamps Sean designed and did take the plans down for now.

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Adding SSL to transmission’s web interface…

If you’re using transmission’s web interface to manage your torrent downloads, and you are doing this remotely (from outside your LAN), you might want to add some privacy.

As previously posted there are ways to use magnet links with transmission’s web interface. This webinterface works well when you are on your local network aka LAN and don’t have to fear prying eyes.
The moment you’re using the transdroid android app or your laptop in a coffee shop the commands and responses of your transmission daemon at home can be read by anyone.

Luckily the transdroid android app offers an SSL option. All you have to do is configure a proxy on your transmission daemon machine.

Here is how:
Install nginx (a lightweight http/https server):

1
apt-get install nginx

Continue reading Adding SSL to transmission’s web interface…

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Bitcoin Paper Wallet Treasure Chest…

The Bitcoin Paper Wallet Treasure Chest
The Bitcoin Paper Wallet Treasure Chest
One of the challenges with bitcoin is to store them securely. There have been several well known incidents where Bitcoins have been stolen. It is no mystery. Bitcoin IS money! It’s the same with Euros or Dollars, when you have it lying around it will eventually be missing.

There is a twist with bitcoin to regular money. With Bitcoin one single piece of information is enough for the thief to steal your Bitcoins: Your private key. With Bitcoin it’s about keeping this piece of information secret.

Continue reading Bitcoin Paper Wallet Treasure Chest…

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