robin's blog

Part 1: Installing OpenCV 3.1.0 on Raspberry Pi Debian Jessy with Java Library

  • Posted on: 26 April 2016
  • By: robin
terminal  Installing OpenCV

The Raspberry Pi has become a Icon. I have nearly 10 Raspberry Pis and i love every single one of them. ;-) In December 2015 I started my Smart Mirror (Magic Mirror) Project and now its finally ready. Or better said the Hardware or the Smart Mirror is finally ready. What is now missing is a mind blowing Software. While searching for features a friend of my, Hendrik,  came up with a mind blowing idea. A absolute key feature for a Smart Mirror - Face recognition.

Python: MapReduce Word Count

  • Posted on: 19 April 2016
  • By: robin
Python: MapReduce Word Count
text = '''...'''
list = text.replace('\n',' ').split(' ')
clist = map(lambda word: (word.lower(), 1), list)
result = {}
for word in clist:
    if(word[0] in result):
        result[word[0]] += 1
        result[word[0]] = 1
clist = [(k,v) for k,v in result.iteritems()]

Manual Firmware Update Instructions For YI Home Camera ver. A

  • Posted on: 11 March 2016
  • By: robin

I recently had to update my Xiami Yi small ants camera firmware since it was not compatible to the app anymore.  Step one is to find out what Version do you have. On the back of the xiaomi small ants you can find a short code where the 3rd and 4th digit tell you what version you got.

CN, ZP, ZH is for China and HongKong - Download Firmware for Xiamo ants camera

Android 6.0 - You CAN NO longer access the Mac-Address? You can !

  • Posted on: 5 March 2016
  • By: robin

Okay that's new to us android developers: You can no longer get the hardware MAC address of a android device. WifiInfo.getMacAddress() and BluetoothAdapter.getAddress() methods will return 02:00:00:00:00:00. This restriction was introduced in Android 6.0.

I wanted to know if this is true. So I tested this on my OnePlus One (Android 6.0.1 Cyanogen).

Capture WiFi / WLAN / 802.11 Probe Request with tcpdump

  • Posted on: 4 March 2016
  • By: robin
A Probe Request is a special type of WLAN frame sent from a terminal-device (for example your smartphone) to ask all AP nearby for their presence. This allows you to find out if smartphone or other wifi enable devices are close to you. Since many users want to use the Probe Request to identify devices:

Facebook süchtig ? Seiten wie Facebook blockieren (Mac, Windows, Linux)

  • Posted on: 29 February 2016
  • By: robin
Block Facebook

Internetseiten wie Facebook haben sich zu den beliebtesten Beschäftigung der meisten Usern entwickelt. Doch leider lenken sie uns oft ab, sodass Studium und Arbeit darunter leiden. Doch was kann man tun um von dem zwanghaften Verhalten Facebook zu besuchen wegzukommen ? Die Lösung ist einfach: Wir blocken die Seite einfach für unseren Rechner. Diese Methode ist zwar komplizierter als Browser Plugins, jedoch effektiver. Ein Browser Plugin ist schnell deaktiviert und i.d.R.

Raspberry PI 3 kaufen in Deutschland (Preisvergleich)

  • Posted on: 29 February 2016
  • By: robin
Raspberry PI 3 Preisvergleich für den Kauf in Deutschland

Der beliebte Mini Computer feiert seinen 4. Geburtstag und noch viel wichtiger: vor kurzem ist der Verkauf des Raspberry Pi 3 gestartet. Laut offizieller Website der Raspberry Pi Foundation kostet der Raspberry Pi 3 nur 35$ (knapp 32 Euro). Wie wir sehen werden stimmt das jedoch nicht ganz, zumindest in Deutschland.

Gut zu wissen: Da Form und Größe absolut identisch zum Raspberry Pi 2 Model B sind, können alle Gehäuse und die meisten anderen Zubehörteile bei der neuen Pi Version verwendet werden. Außerdem ist WLAN und Bluetooth 4.0 schon mit an Board.

In Deutschland kann man den Raspberry Pi 3 bei vier Partnern von element14 kaufenEXP GmbH (Germany), Heinz Büchner Elektronik (Germany), Pollin (Germany) und Watterott electronic GmbH (Germany). Wir haben die Preise verglichen (Stand 29.02.2016).

Android Vibrator pattern explained

  • Posted on: 29 February 2016
  • By: robin
Android Vibrator pattern explained

The Android Vibrator feature is supported by the majority of the android devices. It is easy to understand. First of all the feature requires premissions. So first thing you need to do is edit your AndroidManifest.xml:

<uses-permission android:name="android.permission.VIBRATE"/>

Next: The Vibrator service.

 Vibrator vibrator = (Vibrator) this.context.getSystemService(Context.VIBRATOR_SERVICE);
Now you need to define a pattern how the Vibrator should vibrate. The explaination in the Android documentation for Vibrator is:

"The first value indicates the number of milliseconds to wait before turning the vibrator on. The next value indicates the number of milliseconds for which to keep the vibrator on before turning it off. Subsequent values alternate between durations in milliseconds to turn the vibrator off or to turn the vibrator on."