tellstick web UI

When executing latencytop as normal user, most probably you will get this error message:
$ latencytop
mount: only root can do that
Please enable the CONFIG_LATENCYTOP configuration in your kernel.
Exiting…

Easy and obvious solution is “sudo” … and you are good to go
$ sudo latencytop

However, if you don’t want to type “sudo” everytime you want to use latencytop as a normal user, then the Linux Capability comes handy.
# man 7 capability

To use this, first install the required utilities. In Ubuntu, it is called:
libcap2-bin – basic utility programs for using capabilities
# apt-get install libcap2-bin
# sudo setcap cap_dac_override+ep /usr/sbin/latencytop

”
Here, CAP_DAC_OVERRIDE means: Bypass file read, write, and execute permission checks. (DAC is an abbreviation of “discretionary access control”.)
e = Effective
p = Permitted
”

$ latencytop
Bingo .. you can use latencytop as normal user. No need to worry about sudo anymore.

Userful Links on Linux Capabilities :

http://linux.die.net/man/7/capabilities

http://www.linuxjournal.com/article/5737?page=0,0

http://www.linuxjournal.com/magazine/making-root-unprivileged

http://www.sevagas.com/?POSIX-file-capabilities-the-dark

http://www.friedhoff.org/posixfilecaps.html

Power Adapter hack

Here, a “worked-around” for the laptop socket incompatibility with some pieces of wire that I got from the common “bread” cover. Open contacts are dangerous.. Still, if you know what you are doing, just go ahead..

On the way back, I saw a bunch of Remote controlled Mains socket sets. At a price range of less than 200 Swedish Krona, it was definitely approachable. After some search, picked a set of NEXA PE3 Mains adapters with a remote control for 179 SEK. A complete home automation system in Linux was one of my dreams for a long time.So, decided to go ahead and buy it.

Still, with this set, I will have to open up the remote and connect it to Arduino or some other board to control it from Linux. Since I wanted a system made out of “Off the shelf” components, decided to buy the Tellstick USB device which was available in the same section for 599 SEK.

After reaching my room, connected the Reading Light, Main Light and the very old TV (with no remote) to the 3 Mains adapters and started pressing the remote’s button. To my surprise, nothing worked. So, switched on the laptop and started looking at the NEXA’s documentation:

http://www.nexa.se/res/pdf/PE3-manual_no-Mars-08.pdf

From the documentation, it was clear that, the Nexa Mains Sockets and the remote control needs a “Pairing” operation. Since each Mains Sockets are individually programmable, we can connect any button with any Sockets (no duplication).

USER GUIDE Model: PE3-1500
SETTING THE CODE: learning function
* Prior to normal operation, you must program the transmitter to the receiver.
* Connection light receiver, contact the outlet
* Indicator light on the receiver blinks slowly for 5 seconds.
* Within 5 seconds after the light on the receiver flashes recorded transmitter near the receiver. Press the ON button on the specific channel (channel 1, 2, 3)
* Recipient light stops flashing. The LED flashes twice to confirm that it has learned the code.

After the “pairing”, the remote began to function properly. It is alway better to connect the devices after this pairing process.

Controlling NEXA PE3 remote switches using a Tellstick USB device in OpenSuse:

One good thing about the NEXA PE3 was each Socket can be controlled with a maximum of 3 different sources. ie, I can use the existing remote control and my laptop with Tellstick to control the same Socket. One down-side is that the status of the Sockets reported by the program will not be very reliable as it uses a 433.92 MHz uni-directional signal to control the sockets.

The installation process starts here:
Installation: http://developer.telldus.com/wiki/TellStickInstallationSource

# zypper install libftdi1 libftdi1-devel libconfuse0 libconfuse-devel
(I already had cmake in my OpenSuse 12.2)

Downloaded the latest Telldus-core :
# wget http://download.telldus.se/TellStick/Software/telldus-core/telldus-core-2.1.1.tar.gz
# tar zxvf telldus-core-2.1.1.tar.gz
# cd telldus-core-2.1.1
# cmake .

Modify the ‘cmake_install.cmake’ to use “/usr” instead of ‘/usr/local’
- SET(CMAKE_INSTALL_PREFIX “/usr/local”)
+ SET(CMAKE_INSTALL_PREFIX “/usr”)

# make
# sudo make install

From the NEXA documentation, we can see that the socket is “selflearning-switch”. So, my configuration for NEXA PE3 for is like this:

After connecting the TellStick to Laptop’s USB, start the Telldus daemon:
( We can make it start automatically by writing an init script wrapper)
# telldusd –nodaemon

Now, take each Power Sockets and “pair” it with TellStick using this command:
# tdtool –learn 1
(for the Main Light in this socket)
# tdtool –learn 2
(for the TV)
# tdtool –learn 3
(for reading light)

After connecting the devices, list all of them using the command:
# tdtool –list
Number of devices: 3
1 Main Light OFF
2 TV OFF
3 Reading Light OFF

Now, the fun begins… Control each device using the command:

# tdtool –on 1
# tdtool –off 1

(switches the Main light on and off)

If you are interested in GUI program to control devices, Telldus provides a QT based program:

http://download.telldus.se/TellStick/Software/telldus-gui/

Warning : This is “not” a work of fiction. Names, characters, places and incidents either are “not” products of the author’s imagination or “not” used fictitiously. Any resemblance to actual events or locales or persons, living or dead, is entirely real.

One fine summer day, my friend was walking towards the Central Railway Station in Helsinki. One Finnish teenager requested him for some help — “See, my mobile phone stopped working. Can you please give me your mobile for a minute ? I just want to call my relatives”

That friend never had a bad experience from the local people and he immediately handed over his mobile to that teenager. He politely took the phone, made a call and returned the phone almost immediately. He didn’t understood what the teenager did till he got the phone bill which was marginally higher than the regular one. From the bill, he came to know that the teenager has misused his phone to order Pizzas and the bill was charged to his mobile phone bill.

After some research, he found this link:

http://www.uphill.fi/?id=news&uutis_id=00013

”
The service is available to all customers, who have not blocked calls to special payment services. The service is charged on the caller’s phone bill regardless of the user’s operator.

In practice, the customer calls a restaurant-specific, special payment phone number (a 0600 number), after which the restaurant immediately receives a notification of payment. The order has been made and paid! Also home delivery orders can be paid using a mobile phone. After receiving an order, a restaurant employee calls the customer to confirm the order, ask for the delivery address, and the desired pizza toppings. The advantage of mobile payment is speeding up service. The call itself is made easy for the customer, as the customer’s order reaches the restaurant directly after calling the given mobile payment number, and the pizza is paid for before delivery.
”

My parents wont be interested in fancy smart-phones. They generally like the simple “for the purpose” devices like Nokia 1100. Mother wasn’t that happy with what I gifted her last time – a Robotic vacuum cleaner from Samsung. “It won’t clean the corners”, she complains.

So, what should be the “gift of the trip” this time.. I was thinking about it and moved to the second floor. Solar lamps section at the end of the second floor amused me.. My naturally sarcastic mind said –

Hmm.. what will these guys in Helsinki do to charge these Solar lamps during this shorter and darker winter days ? These lights must be pretty much a waste of money for them…

Oh, wait, the rational mind said.. what if I try these Solar lights at my house.. Kerala is a sharp contrast to Helsinki. Generally sunny, warm with longer day time – ideal for Solar lights. So, without much thinking, I bought 4 pairs of Solar Garden lights and a Solar security light for 48 Euro (Rs. 3000 – It is the subsidized price, I believe)

After reaching Home, I happily installed the Solar Garden lights in the “upcoming” garden and Solar security light just in front of the gate. The LEDs in the Solar Garden lights were automatically switched on when the circuit in it detected darkness around 6.45 PM. The LED lights kept on working upto 10.00 PM. The Solar Security light had a bigger Solar cell and it lasted the whole night as it automatically got switched on and off whenever it detects movement in the nearby area.

During the return trip, I was happy about the decision as the lights were working almost 4 hours (with 800 mAh AA battery) continuously after an average sunny-day’s charging. It lasted for 8 hours when I installed a 1200 mAh AA battery in one of the Solar garden lights.

Parents were happy about it as this was the first time I bought something that didn’t result an increase in the Electricity bill

This aroused my curiosity. I was aware that Nokia exited the Japanese market even before this incident. Then what we should do to handle that nuclear disaster in Japan? After the lunch, I visited the exhibition and asked the same question to a guy standing there.

“Well”,he started, clearing his throat. Though we don’t market any of our products in Japan, some of the vendors of electronics parts are from Japan. Because of the nuclear disaster, most of the electronic parts from that region of the Japan “may” be contaminated by the nuclear radiation. This may cause troubles to our customers who comes in contact with those phones with those parts which are contaminated by the nuclear radiation. In order to avoid that scenario, we request the vendors from Japan to check for Radiation problems from their site and we double-check it once the parts arrives from that location and ensure that our customers are safe from the related problems.

I thanked that guy and moved to my place. To be frank, I wasn’t aware of this kind of scenario. A disaster which can badly affect virtually every humans and all types of industries in that region. It might affect the guys who are living in another continent if the Corporations aren’t aware of what they are doing. I must admit, in this case, I respect Nokia for their care to their customers.

Coming back to the subject, I respect Japanese Government’s decision to ‘switching off’ final nuclear reactor. Similarly, protests are going on against Kudankulam Atomic Power Project, Tamil Nadu in India. I wish them success and ending this with the words of Nikola Tesla:

“The idea of atomic energy is illusionary but it has taken so powerful a hold on the minds, that although I have preached against it for twenty-five years, there are still some who believe it to be realizable ” – in a peaceful way.

1. Helmet : Helsinki Metro Library : http://www.helmet.fi/en-US
2. Tennis Palace (name of a Movie Theater, basically to watch movies)

4. Small and beautiful Beaches

5. verkkokauppa : The Biggest Electronics store in Europe (they claim so.. ) : http://www.verkkokauppa.com/

6. Cycling through the beautiful islands in Helsinki and Espoo.

7. Hietaniemi Cemetery (Walking through the Lake side is a refreshing experience)  http://en.wikipedia.org/wiki/Hietaniemi_cemetery

Last weekend, decided to visit Verkkokauppa to buy some basic cables to setup my personal “Lab at Home”. There I found some interesting things like Mini Weather Station and  Maplin USB Robotic Arm. To follow my desire to play with some USB stuff, I bought the USB Robotic Arm. The Software CD that shipped with the H/W was only for Windows and  all I wanted was to make it work with Linux.  After  google search, I landed in this page which had some great information related to the Reverse Engineering details of Robotic Arm’s Protocol :

http://notbrainsurgery.livejournal.com/38622.html

After some hours of writing – testing – rebooting cycle, the driver for the USB Robotic arm was ready and I pushed that to Github:
https://github.com/maxinbjohn/robotic_arm_driver

That followed  a simple Python program to control the USB Robotic Arm using the driver:

https://github.com/maxinbjohn/robotic_arm_driver/blob/master/examples/python/motor.py

Finally uploaded the video of controlling  Maplin USB ARM from Linux.

Youtube link:  http://www.youtube.com/watch?v=UjQgqJIH82Q

Subject: Re: — Ecosystem —–

>The Indian market is fascinating and complex.  While it's easy to think 
>of the country as a single market, it is in fact 22 separate states,

Here, I would like to point out that, "India is a federation composed of
28 states and 7 union territories".

http://en.wikipedia.org/wiki/India

India is really "complex" - I know it, because I am from India  

Best Regards,
Maxin B. John

-----

The reply from that guy was so funny that I laughed and virtually fell from my chair.. It was just 9 words :

 Subject: Re: Re: --- Ecosystem -----

Thanks...I got the info from the Gurgaon team