These Ritto doorbells are fairly popular is most households in Germany especially in high-storey apartment buildings. There are two sources of signals that trigger the ringer inside your apartment:
1) Doorbell outside of the main building that interacts with main “intercom” that decypts the signals and channels the signal to the ringer inside your apartment

2) Doorbell in front of your apartment door that sends a simple electric pulse to the ringer

Anyway, the process is fairly simple. I looked at the initial board of the my doorbell and I figured out there is just a single button that, if I could control in a smart way, would allow me to use my phone to operate the main door of the building.

Figuring out the power-supply

I found out that the intercom sends 30V to the ringer. In order to avoid using any external power source, I thought it would be a great idea to tab on the 30V power source already coming from the intercom.
Benefits:

1. I don’t consume another power socket from outside the ringer
2. I don’t operate on batteries which avoids maintenance

The solution

I used a Sonoff SV as the core component that turns my doorbell smart. It is fairly cheap ($4.85 with long shipping duration), or you could pay a bit more and have a faster delivery from a local supplier in Germany.

There are several tweaks to be done to make the Sonoff SV applicable for our uses.

1. Turn the Sonoff SV into a relay. From the circuit board below, you would first remove the two resistors marked and since I want my Output to be a short (that is, simulate that I pressed the “open door” button), I short the input using a piece of wire.
2. Wires from the pins of the Sonoff SV output are soldered to the Ringer’s button’s pins
3. Now, since the Sonoff SV requires 24V max of input and my doorbell’s supply is constantly 30V, I did the math of voltage division is it turns out that 100 Ohms are enough to drop the voltage from 30V to 24 V approximately, considering the resistance of the Sonoff SV board itself as a circuit.
4. That’s it. With the Sonoff SV turning on, and simulating and on/off by a tap on the button in the eWelink app on my smartphone, I was able to simulate pressing the “open door” button.

Hello folks,

Having issues mounting your flash drive on Fedora 24? Here are quick steps to make things work:

Install the free and non-free RPMFusion repository. The fuse-exfat package is not available in Fedora at install due to patent issues. Thanks Microsoft! As a result, you need to get it from a third-party repository:

sudo rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm 

sudo rpm -Uvh http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

Then install fuse-exfat:

sudo dnf -y install fuse-exfat

Done. Please let me know if it worked, or if you encountered issues!

Greetings,

Shailen

Hello people,

I decided to write down all the steps involved since this topic seems to be quite popular and many people have issues about that, especially when using GMail.

First, the software requirements:

• Python 2.7 + (which comes with smtplib)

For smtplib to work, you need to have SSL and all its accompanying packages installed. I use Fedora. Therefore, go ahead and install openssl-devel:

sudo yum install -y openssl-devel

If you are going to use a python script to send an email, you will need to tweak your Gmail (Google) security settings because my default Google blocks any unsecure 3rd-party applications accessing your account. This is great for security but not good for our python script.

Head to your Google settings (not Gmail settings; you can access google.com by staying signed-in. You should see your email address in the top right corner). Click on My Account and then Sign-in & Security. In the left pane, choose Connected apps & sites. Scroll to the bottom of the page and turn ON Allow less secure apps. Make sure that the settings remain ON by clicking on another menu and coming back to this setting. When I tried it for the first time, the setting seemed to reset itself.

When this is done, the following script should work out of the box:

import smtplib

gmail_user = 'your_email@gmail.com'
gmail_pwd = 'your_password'
FROM = gmail_user # sendmail needs the from
TO = 'recipient@gmail.com'
message = 'TEST msg'

# SMTP_SSL Example
server_ssl = smtplib.SMTP_SSL("smtp.gmail.com", 465)
server_ssl.ehlo() # optional, called by login()
server_ssl.login(gmail_user, gmail_pwd)
server_ssl.sendmail(FROM, TO, message)
server_ssl.close()
print 'successfully sent the mail'

Voilà! If that was helpful, please let me know. Feel free to shoot your question in case you had issues. I will update this document based on your feedback.

Hey everybody,

Yep, these proxy issues are frustrating but the solution is dead simple. Strangely, this is not documented anywhere on the texlive webpage.

1. Download install-tl.zip (standalone) fromt he Texlive download page.

2. Extract and locate the install-tl-advanced.bat file.

3. Add your proxy settings in the bat file.

@echo off
echo Add proxys:
set http_proxy=http://proxy-site.domain.com
set https_proxy=http://proxy-site.domain.com
rem $Id: install-tl-advanced.bat 33536 2014-04-19 09:41:24Z siepo $
rem Public domain.
rem Originally written 2009 by Norbert Preining.
rem
rem Start installer in advanced (perltk) mode. This is here so that
rem it can easily launched from the normal Windows GUI, not just the
rem command line.

call “%~dp0install-tl-windows.bat” -gui perltk %*

4. Open an elevated command prompt (i.e as Administrator) and execute the batch script.

5. Boom and you are welcome 🙂

Hello folks,

A colleague today just said that December is the Friday of the year. The festive period (Christmas) is coming soon and many are excited to upgrade their smartphones by Christmas. Thus, I have leased three top flagship phones in view to compare them. Yes, that is a first world problem and I am always trying to find the best smartphone every. Somehow, I found it hard to get all the perfect and desirable features in one device. Hopefully in the coming years, Project Ara (or similar projects) will attempt to solve this problem.

As we speak right now, some flagship specifications would be:

1. 5.x inch display

I have big hands and I consume a lot of content on my phone. Therefore, any screen smaller than 5 inches would be too small for me. On the other hand, while I could do with a 6-inch phone like the Nexus 6, I would have an issue carrying my phone around as my jean pockets are not designed for such devices.

1. 3500+ mAh battery which hopefully translates to more than 6 hours of screen-on time.

The bigger the better. Naturally, this can lead to a heavier device. A heavy device is undesirable as the latter becomes cumbersome while doing sports activities (such as running). As a result, using fitness tracking software such as Runtastic becomes difficult. I could invest in additional fitness bracelets amongst others, but the market is still nascent at the moment and I do not want to maintain too many devices.

1. Qualcomm Snapdragon 805 processor + Adreno 440

At we speak right now, Qualcomm has a leading edge on mobile processors, although there is increasing competition at the moment. Samsung is pushing its ARM-based Exynos processors, LG plans to publicly release its own in-house ARM-based BIG.little Nuclun (previously known as Odin) processor in 2015 and nVidia has its own System on Chip (SoC) which integrates an ARM-based CPU and their own in-house built CPU. Apple has its own ARM-based Cortex mobile processors. Somewhere in this big crowd, Intel offers some powerful solutions based on the x86 microarchitecture. The year 2015 will be very interesting as Intel (as publicly announced) plans to push forward a high-performance, battery-friendly SoC based on the 14nm Cherry Trail platform.

In the end, it will be a war between ARM vs x86. Healthy competition is crucial for the sake of technological progress. I am eagerly looking forward to 2015.

1. micro-SD card slot

Not everybody has access to high-speed mobile internet. LTE coverage is still very limited, even in developed countries. Lastly, a sizable proportion of people (I do not have a source/quote for this, but this is my general impression, especially following the NSA scandal) do not trust online storage service. In this limelight, some people would prefer storing their pictures and other files locally on their phone. The storage size to price ratio is increasing and therefore, micro-SD cards are very desirable.

1. A 12 MP + camera that can record in at least 2K and support optical image stabilization (OIS).

Mobile cameras are a pocket-camera market killer. Life is beautiful. I would not want to miss taking pictures of beautiful sceneries or of silly friends.

A flagship phone this year will naturally support LTE (at least cat.4)

Now, coming to the head-to-head clash among the three top phones of Q4 2014:

My (subjective) experiences with the Sony Xperia Z3:

The Good:

• The Sony Xperia UI is nicer more productive than stock Android. I am able to search for apps in the drawer and organise my apps in folders in the app drawer itself. When I switched to the Moto X, I immediately found it very annoying to scroll many pages to find my apps.

The Bad:

• The bezels are too big. This unnecessarily makes the phone very long. Sony could have done a better job to trim these bezels. Sharp Aquos rings any bells?
• The glass back can easily be scratched. I searched but I could not find whether the glass was Gorilla Glass 3. In any case, what I know is that the glass is covered with a shatter-proof layer of plastic. The glass itself is scratch resistant (thus probably a Gorilla glass). As a result, the (permanent) scratches on my phone were on the shatter-resistant layer hence having a scratch-resistant gorilla glass is a little bit an overstatement to me.
• I prefer the direction that Intel is going – no wires! Thus wireless charging is important for me. The Z3 lacks wireless charging. With these water-proof flaps, wireless charging would have been a great addition.

The Ugly:

• There is a serious lack of reasonably priced casing for the Sony Z3. If you manage to land yourself an expensive leather case, you will not be able to use the Magnetic Charger holder (also known as a charging dock, although I think the term dock here is an overstatement; you can only charge your phone with that holder.) properly. Yes, the phone is splash-resistant. I saw splash because I have heard somebody who plunged the phone in a 1m deep pool and the phone got damaged. However, popping up the charging flap every time one has to charge the phone is very annoying.

Although the back camera is okay, the front camera is very pixelized.

Moto X (2014)

The Good:

• Small bezzels
• Great AMOLED screen

This is a matter of preference. I found the AMOLED display in the Moto X more vivid (in terms of colors) than the IPS (LED) display on the Sony Z3.

• great built-in software from Motorola

The Bad:

• Lack of wireless charging

The Ugly:

• Short battery life

Every day, I travel approximately 40 minutes each way to work. I use that time to read the news on my phone. At the same time, I stream Spotify music to my bluetooth headset. I always have Wifi, data and bluetooth because I do not want a hassle of toggling them all everyday. At work, I use my phone once a while. Thus, I approximate 3 hours of screen-on time. Such a lifestyle gives me 12 hours. If I start my day at 8:00am, by 20:00 in the evening, I am out of juice. Thus, if I am planning an evening out, I make sure to charge my phone during the day. I would have preferred a battery that fits my lifestyle. The battery in the Sony Z3 lives up to my lifestyle.

LG G3

The Good:

• Wireless charging
• Very nice, bright display
• knock-on/off feature

This feature is great although I found that the knock-off feature only worked when I knocked twice on a empty space on the home screen. Thus, I always have to keep some empty space on my home screen and I have to target that empty area all the time for the feature to work.

The Bad:

• LG UI is not enticing enough.
• The buttons at the back are not programmable.

The Ugly:

• Display drains the battery very fast

As a very last point, I found the sim card holders that the Sony Z3 and the Moto X use to be quite silly. Both phones require nano-SIM-sized (FF3) cards but they provide a micro-SIM-sized holder that you use to insert the nano-SIM. I guess it would have been simpler to just allow the insertion of micro-SIMs right away without the need for SIM holders. I have had to go out of the way to get my micro-SIM cut to the nano size. And my bad luck, I lost the nano-SIM holder for the Sony Z3.

I reckon you would not swap SIM cards on a frequent basis, but I found micro-to-nano-SIM tray unnecessary.

Final Words
I picked the Sony Z3 over the Moto X(2014) and the LG G3. The Sony Z3 had a better battery and is future proof in terms of specs (I am sure that the Qualcomm 801 processor and 3GB of RAM should allow me to install any apps for the next 2 years). I do not have a Playstation and therefore the bundled Playstation remote app that comes bundled with the Sony is useless for me. However, if you own a playstation and you are hesitating which phone to buy, the race suddenly becomes easier.

I hope this article helped. Have fun with your next purchase.

Ladies and gentlemen,

Note: Until the end of this blog article, I talk about my history why I came where I am now. You may fast-forward to the next articles.

Times have changed. I still remember the time when I was kid and I was starting with computers. My father bought the first family computer to do his basic office work (mainly using Word.) It was an Acer desktop PC running Windows 95. It had 2.1 GB of hard disk space and 32 MB of RAM. At the time of purchase, this desktop PC was supposedly the top-in the line machine.

Back in the days, nobody really knew how to use the computer. My father knew only the basics of the basics (turn the computer on, and open a program.). Next in the line, came my elder brother who, at the time, at best knew how to install a PC game.

Internet was scarce commodity since we were using dial-up. Dial-up networks were ridiculously slow and we paid per minute.

Then there was me. I was not allowed to use to computer at all, since I was known to break stuff. However, a couple of months later, I was allowed to have access since we were learning how to use Microsoft Paint at school. And they were right; I did end up breaking the computer – at least the software. I somehow crashed Windows entirely and it would boot anymore. Needless to say, my father was extremely furious as he had to pay the technician to fix it.

Speeding up a bit and skipping some part, a few months later, I had started programming. It was the most basic of things. I was automating some tasks with batch. Batch was fun. It was sequential, logical and loved the jumps, done with the goto: statement. I was still small when I started with Visual Basic, all on my own. I did some stupid programs and they were fun.

A bit a year after the purchase of that desktop machine, the latter was upgraded to Windows 98 and to 64MB of RAM. I was already more knowledgeable in computer stuffs than anybody else in the family.

It appears that a significantly large amount computer professionals these days happen to learn their first programming language on their own. All of them started with proper languages (like C, C++, python) or scripting languages or markup languages (like HTML).[sources: sampling my immediately network].

Well, my generation of people were born in the age of uni-processors which makes sense why we start with such languages. We then get acquainted to MPI and OpenMP at the university.

Times have changed now, and as multi-core processors are becoming the de facto standard these days. Even low-powered devices like mobile phones are multicore. As the trend speaks for itself, it will be time to start teaching MPI and co. right in high school itself (or even before).

While I started with serial programs, I guess in a few years to come, kids will start right away with algorithms. The basic books about programming will already guide them to think into parallel ways of solving problems. Serial algorithms will be a thing of the past and will not even be teached at all (maybe in history classes.). Just kidding.

Anyway, if you were like me and were raised in the uni-processor world and you want to embark on the HPC bandwagon, it is paramount to understand some core computer architecture concepts before you are able to grasp why things are done the way they are.

You will need to understand what is going on when a processor is multicore. You will need to know what is a NUMA architecture. (I assume you know clearly the von Neumann architecture. What, no? Don’t panic :)) I will introduce it, and briefly tell you about the Flynn’s taxonomy. Knowing these fundamental architectures, you will have the basic foundation to embrace the parallel world.

More coming soon..