Arduino Based Phone/ Bluetooth Controlled Bot

Hello

In this article I discuss how I made a Bluetooth Controlled Bot.

Time Required: 

1 Hour

What is it ?

A Bluetooth controlled robot. You can control the movement of the robot (forward, backward, left, right) through an Android device. I used an application named Sena Bluetooth Terminal to send data from my android device to the robot.

Parts Required

1. Arduino Uno

2. Battery Operated Motor (BO)

3. Wheels

4. Chassis

5. L293D Motor Driver

6. 2 9V Battery

7. HC05 Blutooth Module

Most of this parts can be found on ebay. 

If you are reading this out of shear interest, chances are high that you know something to many thing about arduino microcontroller. If not, than just google it.

Before you proceed in making this, learn how to handle the HC05 Bluetooth module. Below is the link that will show you how to get into AT command mode and configure the Bluetooth module. 

https://www.youtube.com/watch?v=-z_0aU8VHzk

Once everything is fine with the Bluetooth module you can fall in line with this article.

The figure below is self-explanatory and here is the wiring information.

The Arduino Uno should be powered with a separate 9V battery (Not shown in figure)

L293D Motor Driver and Arduino Pin Connection 

Pin 1 goes to Arduino Pin 2

Pin 2 goes to Arduino Pin 4

Pin 3 goes to Motor 1.1

Pin 4 goes to Ground

Pin 5 goes to Ground

Pin 6 goes to Motor 1.1

Pin 7 goes to Arduino Pin 5

Pin 8 goes to Arduino 5V pin

Pin 9 goes to Arduino Pin 3

Pin 10 goes to Arduino Pin 6

Pin 11 goes to Motor 2.1

Pin 12 goes to Ground

Pin 13 goes to Ground

Pin 14 goes to Motor 2.2

Pin 15 goes to Arduino Pin 7

Pin 16 goes to 9V supply

Bluetooth module and Arduino pin Configuration

RXD pin to Arduino pin 11

TXD pin to Arduino pin 10

VCC to Arduino 3.3V

GND to Arduino Ground

Note: It is better to use a L293D breakout board rather than the lone IC. They are easily available in ebay.

Note: Arduino ground, HC05 Bluetooth module ground and 9V Ground is common as seen in the figure

Below is the link to the Arduino Sketch or Code

https://drive.google.com/file/d/0BzjnppE-h-xeV21RVzk2MlJkZGs/edit?usp=sharing

Hydraulics !! You see them ! Now learn a bit too !!

I have noticed that even if many people do not have a electronics background but still some of them can manage  well to study electric circuit diagrams. They know resistors, lights and some  even know an op-amp.

But, do a non-mechanical background people manage to study mechanical diagrams ? No ! I don't think so. Atleast, I was not able to study any of them before the Mechatronics subject introduced in this semester of my engineering course.

Our lecturer told us to submit an assignment which he already explained. The assignment was about explaining the 'Basic Hydraulic System'. Rather then copying the assignment from anywhere else, I choose it to write it in my own terms because it was quite of a interesting stuff, and a must-have basic knowledge of mechanical system.

So here it goes!!

 

Explanation of a Hydraulic System

Figures show a hydraulic system. The reservoir is where the oil is stored. It is connected to a pump which pumps the oil. The pump is accompanied by a motor for it to function. Also seen in the figure is a MRV (main relieve Valve) which relieves the hydraulic system from high pressure resulting from excessive oil. This excessive oil is released into the reservoir.

We have a 3 position 4 way direction control valve. The control valve is ‘3 position’ because it can be set to 3 different position and at every position it executes an important task of the entire system. ‘4 way’ means that there are 4 unidirectional path through which the fluid (oil) can flow. Now let us understand each of the position in detail in context of the system.

At position one: (P1)

The pump pumps the fluid from the reservoir. The ‘One Way Valve’ ensures that the fluid travels only in one direction. The control valve is in such a position that one inlet lets the fluid in towards the double acting hydraulic ram and one outlet takes back the fluid from the hydraulic ram such that the fluid goes back into the reservoir. The pressures differences created by the fluid make the piston moves outward.

At position two: (P3)

At this position the inlet (and outlet) fluid goes to the other side of the hydraulic ram (opposite side as compare to position one). The pressures differences created by the fluid make the piston moves inward. (Opposite to position one)

At position three: (P2)

This is the neutral position. Here the fluid is blocked by the control valve so that no fluid movement can take place between the hydraulic ram and the rest of the system. This halts the piston and piston becomes stationery. This position has a great significance because a user may want to dynamically control the piston by operating the control valve. At this position a user can halt the piston at any instant of time.

Solar Tracker Based Solar Panel using Arduino

First Look!!

Hello, till date I have posted number of articles in my blog, but none on my core interest of Arduino microcontroller. This is because I’m still learning it and lots remain to be learnt. Nevertheless here is one of my very simple projects on Arduino microcontroller. I’m sure this post will be a boon for all those newbie on Arduino and equally stupid for the microcontroller experienced guys. For any questions or comments you can mail me at rishiraj.in@gmail.com or Facebook me! (Link at right side of this page)Oh, forgot to mention, this project won a small prize at a small project competition in my state

Solar Tracker Based Solar Panel using Arduino

In this post I present you a prototype of a solar tracker based solar panel. The solar panel changes its orientation according to the direction of the Sun. 

Final Prototype of the Solar Tracker based Solar Panel
Notice how the 3 sensors are kept at the Sensor Board

How it happens?

Basically there are sensors mounted. This sensor when illuminated by the sun rays gets activated and sends a signal to the Microcontroller. The microcontroller in return instructs the motor to move by the specified speed and direction.

There are three sensors fixed in such a way that each sensor gets activated at 3 instants of the entire day, i.e. Morning, Noon, and Afternoon. As the sun raises the first sensors gets activated due to ray of sun falling on it. As a result the Solar Panel orients itself to receive the early morning sunrays. Similarly the Solar panel orients itself when it is noon and afternoon to receive the sun rays efficiently and thereby increase the efficiency of the solar cell.

This dynamic Solar Panel has a greater efficiency since it can illuminate its solar cell even at the morning and afternoon time of the day.

Since it is just a prototype hence I have used torch light to depict sunlight. I made sure that the torch light illuminates only one sensor (LDR) at a time, i.e. one sensor for Morning, one for noon and one for afternoon.

Technical Aspect (Not really)

The Motor and the Sensor (LDR) is controlled by Arduino Microcontroller. The sensor has a predefined threshold value which is crossed when it is illuminated. Once the threshold value is crossed the Arduino sends an instruction to the motor to move.

To make sure that the current demand of the motor is met without affecting the microcontroller, the Motor is connected to a Motor driver (IC L293D) circuit which in turn is connected to the microcontroller.

To control the speed of the motor, PWM technique is used.

The Circuit

The image below shows the circuit, though it looks messy but trust me, it’s very simple.

Blue Wire: Connected from digital Pin 10 and 11 of Arduino to Pin 2 and Pin 6 of L293D Motor driver IC.

Green Wire: the 5V power supply from Arduino to Pin 1 and Pin 16 of IC L293D and also to all the LDRs as shown in figure.

Orange Wire: From Pin 3 and Pin 7 of IC to the DC Motor.

Red Wire: 9V external DC supply. This supply depends on the rating of the DC motor used. In my case I had a 9V DC motor hence 9V supply.

Black Wire: Common ground of the entire circuit. Pin 4, Pin 5, Pin 12, Pin 13, and Arduino ground Pin, 9V battery ground.

Resistor: I just used 100 Ohm resistor and this was chosen randomly. You can use any low resistance.

The Arduino Sketch (Code. . .)

Download It ! ! ! 
You may have to change some part of the Code depending on the intensity of the light where you keep the prototype and the intensity of the torch light used. I guess you'll do it easily, in case of any error or problem write to me.

Android Apps, A Boon for Women Security

Blame it on evil thoughts, narrow mentality or a non-integral state of mind but the facts remain undispersed. The fact that crime against women is increasing steeply and what we saw last December in Delhi was beyond the unimaginable. Blaming or starting over a new course of discussion on this issue will be of little help and the need of the hour is strong self-security measures a girl must have. This article throws a light over some specific security measures that a girl can easily undertake through her mobile phone to prevent any unforeseen incidence.

Google’s Android platform saw some new entrant on January after the gruesome incident last December. These new Android applications are free and very easy to use and access. Let’s take an overview.

1. Nirbhaya: This name is symbolic and was given to the deceased victim. This Android application sends a distress message with the location to people in a group specified by the user in emergency situation. Apart from local police authorities, hospitals you can have your close relatives on the group. You can also customize the type of emergency and assign different groups for different emergency. This application is available in the Google Play store

2. Fight Back: This application generates a security alert when user pushes a central button. The security alert and the exact location of the user are sent via SMS, Facebook and email to people specified for help. Available on the Google Play store

3. Me against Rape: Beside the feature like above this application also has some advanced add on like activation of cell phone camera and voice recorder to act as evidence against eve-teasers. It sends location coordinate to all the people predefined on the list every 10 minutes so that the user’s location can be continuously tracked. Google it !!

Follow your instincts; there is always an unnatural feeling before an unnatural happening.

(With inputs from 'digit')

Republic Day in Guwahati

I honestly don’t know if any bandh was called in Guwahati on the account of Republic day but this region of India has hardly seen any celebration on this day. Usually a boycott is called for by innumerable organization threatened with dire consequence and people choose to stay at home and laze around.

 As of me, I was lucky on this 26th Jan’13. My entire family went out for a short distance outing and we had a good time, and yes, we are safe of course safe. It is the people who can bring a change. Let any organization boycott the Republic Day celebration but the vast population of people should not. People of this region are Indians and governed by the Indian Government so why to support any such organization whose motive mainly lies in disrupting peace?

Republic day or any National day must not be restricted to Institutions and Government offices but to each and every home, each and every street.

The picture at left show some young boys cheering up the Republic Day celebration and at the right, a deserted street, typical as if a curfew has been imposed. We need more like the enthusiast in the left picture and change the image of the right picture in future.

City Bus Drivers in Guwahati -An observation

I’m a regular bus traveller in Guwahati but I usually avoid the seats near the driver because it’s hot in there and secondly the noise inside the cabin is intolerable to my ears.

Never the less, I had to sit in one of the seat near the driver’s cabin while returning from a market in Guwahati and following are my observations of the bus driver.

1. Horns from behind, horns from side and horns from left side too. I guess there is no one compared to these Bus drivers who has to hear irritating and continues honks each time they are on the driver’s seat.
2. Beside horns, they are used to hear those voices from behind like ‘rokhai diok’ or ‘rokhabo’ meaning ‘please stop (the bus)’.  Now the bus cannot be stopped at the middle of the road but errant passengers won’t understand it, they just want the bus to stop wherever they want, in case it does not happen then the driver is verbally abused.
3. The policeman comes in at the third. In this city, traffic police personnel (or any other police) can stop a bus wherever they want and fine the driver for being this and that. There are various ways (guess it) in which the bus driver has to get rid of it.
4.  Traffic Jams?? Everyone on the street will blame buses for this, passing by drivers of bikes and cars will pass lewd comment to the bus driver and drive away.

So much they bear and we never indemnify them. We also say the conductors are ill mannered, but ever realized how frustrated they remain doing the only task of collecting money and counting it the entire day?  

Be honest at the bus, pay the right fare always and don’t argue unnecessarily with the conductor or the driver. Let us live up to our virtue 

New Year

As the New Year comes in and 2012 becomes a thing of past, I wish all wishes made by the entire population of the globe be true.

As of me, I hope I turn workaholic in 2013, nothing can be more satisfying to work for what you truly love to do, to work hard towards it and find fulfillment and satisfaction.  My studies will carry on to be what it was, it was not in a good track and I doubt if it will be in the coming year.

Let’s try to be a good individual, productive for the country and responsible towards family, let’s work for it.

A HAPPY NEW YEAR 2013

Books, Copies, Projects,Student and Corruption

One thing the comes into our mind when we say ‘corruption’ is the dirty politics of Politicians, the nexus between Politicians and bureaucrats, rising crimes like rape, robbery and the news of the guilty being given bail because of ‘lack of evidence’. Those people who are honest and powerful in the tree of Law and justice can’t take strict action because they are suppressed by Politicians either directly or indirectly (through goondas). 

1. Instead of blaming the system for being corrupt it is necessary that we try our bit to improve it. But how can we change it? (Mail me your answers)

2. We need to realize this that corruption starts at the root level, it starts when we copy our home work from a friend of us or from a guide book instead of doing it ourselves.

3. It is corruption when we agree to pay more to someone to get our work done early.

4. It is corruption when we do our project by copying it from a site in Internet. Realize that copying and doing by learning has a big difference.

5. It is better to get less marks by doing something by your own rather than getting full marks by copying it. That way you can be proud of the fact that the marks you got is truly yours and the best part is that, you aren’t cheating yourself.

6. Kids who are in their primary education copies a lot from us, if we stand as a true person to them, then they too will go at the right path, that way we can create a chain of good, logical and honest human being.

7. It is also a blunder when teachers allow us to cheat in practical exam. I know that happens in many institutions.

Are all the points above, nonsense??

Wait a minute, many of us won’t accept it in our heart that a friend of us gets good (read high) marks by copying an assignment and we get low marks just because we did it all by ourselves. Well, that is not logical you see, our friend may get good mark by cheating himself/herself. But that way, one is not true to own self.

See, if we are honest and true to our work, then it becomes easier for recruiter to judge us and accordingly we get a Job in a firm/company/business where our thinking/capability goes at par with it. The result, no matter what Job we do, we enjoy it and live life to the fullest.  So, we should be true to our self, so that we can excel in what we are best at, that way our contribution to the society becomes highest and this world becomes a better place to live in  J

WiTricity-Know The Wireless Electricity

Perhaps you know what WiFi is?? Keeping the same thing in mind, wireless electricity has been named WiTricity by Team of Research scientist in MIT who demonstrated wireless electricity by lighting a 60W light bulb kept 2 meters away from the source of electricity. How did they do it?? Let’s find out.

It was Nikola Tesla in late 1800 who first proposed wireless electricity but he was not entirely successful. Later some other scientist tried to modify Tesla’s experimentation of Wireless electricity but in vain. What they did was based on how transformers work today i.e. mutual induction. They worked on two coils, one primary and the other secondary. Current in the first coil induces a magnetic field, this magnetic field couples with the secondary coil to give an output current. But this has many disadvantages. First, the coil needs  to be kept very close to each other, if the secondary coil is taken far from the output then current lags in magnitude to a huge extent compared to primary. To compensate the current loss the intensity of magnetic field can be made stronger at primary by introducing more round of coils but this would waste a huge amount of magnetic field and hence energy since only a part of primary coil’s magnetic field will be coupled. Thus mere mutual induction can’t be used to transmit electricity due to huge inefficiency.

The WiTricity Team and at right an mutual inductive charger

WiTricity uses the similar concept like above but with added resonance to it. The primary coil is made to vibrate at a particular frequency (its resonance frequency); if this frequency matches with the secondary coil’s frequency then transfer of electricity with power loss can be obtained. Thus both the coil must have that much of current with the same resonate frequency. Added resonance changes the construction of the coil to some extent as well. The coil is throughout inductive with capacitive plates at its ends to store the charges, this is how the WiTricity team lit a 60W bulb wirelessly.

WiTricity Demonstartion,

Future Home using Electricity, Source: HowStuffWorks

David Criswell of the University of Houston proposed use of microwave to transfer electricity. He also tells that Solar cell station can be constructed at the Moon from where electricity will be directed to earth via microwave band of spectrum but again the question of maintenance of the solar cell at Moon is questionable. Furthermore microwave may also have health hazards.

NASA also proposed the use of infrared to transfer electricity to charge batteries and they have even used it but infrared requires direct line of sight with object for the transfer thus making it less feasible for the future.

Iamge Source: treehugger.com

 TIPS

Refer http://www.witricity.com/index.html

When it comes to Love, why is it always, ‘I Love You’??

Image: Google Images

The headline looks confusing but let me tell you that this blog post is a result of my googling about ‘I Love You’. Why is it that a lover always wants to say or listen to these 3 words to judge or to finalize a committing relationship? Do these three words have altogether different understanding in a boy and a gal? (or shall I say Man and Woman?)

Love, well let’s not debate about it or know what it actually is but to keep things simple I can say that since your Mom and Dad loves you hence love is the attachment of emotions present in a relationship within own blood. Now let’s keep our family aside, when you term a closing bond between your friends circle as Love, things get complicated there.

Psychologist put forward through their research that it is highly likely that a girl would firstly attempt to propose a boy when it comes to committing but practically it is the boy who does it. Why?? Well, not a single answer can be justified well but psychologist believes that guys are more willing to take a relationship to the next level (please understand what I mean) and this is what a girl is scared of at first and is likely to put down a proposal if she is not fully sure about committing herself. So practically it is the girl who can sense and judge a relationship well, it is she who can judge if it is right for her and the boy to be committed to each other. For a girl it is more alluring and relieving to hear a boy say ‘I Love You’ after the relationship has moved to the next level (Understand) as many boys (you may not agree) tend to break a relationship after the next level thing!

So, a relationship can go seriously wrong if the girl fails to judge a point because boys (mostly) don’t put much of their thinking into it. This is of course not always true, we do see some dumb girls who change their boyfriend often and same type of boys exists as well, but here we are not considering the relationship of fun.

Thus, this blog post gives one of the millions of reasons why it is always, ‘I Love You’. You may not agree and I don’t have any evidence to prove that I’m right.

Thank God, I could keep the post short; I don’t want to debate love just wanted to put a point.

The online storage drives!!!

Considering your personal computer or smartphone, you will have atleast one file which is more than important to you be it document or an image. Why not then keep the file safely over the web in what is known as cloud storage. It is more secure and there is no fear of losing it. Furthermore if you want to share a file to a huge bunch of people then e-mailing the same to so many people can be quite tedious, why not then generate a web link and let people download the file from the link.

Dropbox provides 2GB of free storage to anyone who sign ups. It is easy to use and very helpful at times (trust me). Visit dropbox, sign-up for an account. You’ll be prompted to download the dropbox software which you must install on your PC. After you install the software a new folder will be created on your computer’s root partition, anything you keep in this folder is saved automatically in dropbox servers whenever you are connected to the internet. Inside this same folder you get to see two sub folders, ‘Photos’ and ‘Public’. Anything you keep in the ‘Public’ folder becomes openly available to anyone in the web. To get the web link you simply need to right click the file, select ‘Dropbox’ then ‘Copy link address’. Same is the case with ‘Photos’ folder where you can keep any photos publicly. Simply read the ‘Get started’ pdf and the attached read me text files in the ‘Dropbox’ folder to learn the simple steps. So no matter where you are, your important files are always with you. Just visit www.dropbox.com, sign in and get all the files that you saved on the ‘Dropbox’ folder. Of course installing the ‘dropbox’ software is not always a necessity. You can simply visit the dropbox site and upload the files. As I told earlier, you can keep your files securely so that only you can access it or make it public

Snapshot during and after installation of dropbox in Windows 7. It is also available for different platforms. 

After you run the downloaded file install the dropbox software

In the notification bar, click the dropbox icon and a menu pops up

The dropbox folder, you can see the Public and Photo sub-folder here

Dropbox is present in the Internet for quite a long time now but not so recently has found many competitors. The Google Drive, drive.google.com. Better than Dropbox in terms of storage as it provides 5GB of free storage. After you sign up in the site with your regular google id (which almost all of you have) you will be prompted to download the ‘Google Drive’ Just one click and no installation required. Similar to the dropbox folder it creates a ‘Google Drive’ folder in the same location. Anything you save on this folder is saved on Google servers when internet connectivity is found. Go anywhere and you have the files with you on the web, just go to drive.google.com

On my personal front, I liked dropbox over Google drive simply because I found dropbox more convenient to use and the files were uploaded on the Internet (or say my dropbox account) immediately after I put a file in the ‘Dropbox’ folder of my computer, it was really fast on a slow internet connection. On the other hand Google Drive took a hell lot of time. Even after putting a very small sized file in the ‘Google Drive’ folder it took more than 3-4 minutes for the file to me shown up in my online G-drive account.

The competition is not only between Dropbox and Google Drive. We have Skydrive from Microsoft. It provides 7GB of free storage to its users and upto 25GB to existing users. I personally have not used skydrive so let me know how you find it incase you happen to use it.

These cloud storage options are getting wider and wider with both Microsoft and Google launching Smartphone applications for it through which a user can very easily store files online from his phone. We already know about Google Docs, the online office editing tool. So files (document ones) kept in Google Drive can be edited as well, ofcourse by Google Docs. Dropbox can provide you more storage (additional 512MB) then the existing 2GB provided you successfully invite your friends through referral. If you’re ready to pay then you can get upto 20GB in dropbox. Similar is the storage extension story for Google.

Dropbox, was simple and easy and it still is. Perfect synchronizing, nothing else.

TIPS
How about having Google Drive as a 'Send to' option in the right click menu? Yes, now you can right click any file and then Send to-->>>--Google Drive, its simple.
I got this tip in my regular tech magazine read. In WIndows 7, click the start menu and in the search bar type, ''%APPDATA%/Microsoft/Windows/SendTo'', now drag in the google drive folder to this SendTo folder and you're done.

Safety in Cybercafes

Image Courtesy:clickbd.com

You must have visited cybercafés for various tasks, be it downloading, editing etc. But beneath the work you do in those public computer lies huge set of security issues. An intended person can gain almost many of your personal information like login ID, password, bank PIN code etc. through a public computer from the history of your website visit. If you have transferred a document from your personal computer to a public computer for editing or uploading purpose then someone can gain your personal information from those documents too.

The threat in using a computer in cybercafé comes from keyloggers.  Keyloggers can trace whatever you type in your keyword by means of a software or hardware. For more on keylogger read my earlier post here.  Your web history in a browser or the log files created in your session of using the computer can be beneficial in many way to those who are looking for it.

Here I come up with some simple steps you can follow to be safe on a public computer.

1.    Make sure that you visit a Cybercafé which has a good population of people going in it. This will make your data a drop among the huge ocean of many data getting stored in it thus making it difficult for criminals to break into a specific user data.

2.      Use a cybercafé which has its computers in separate closed cubicles. This prevents others from shoulder surfing your personal information and prevents one from seeing whatever you have typed in your keyboard.

3.    Have a handy USB drive. You can install the portable version of a browser in your USB drive. Portable browser runs from the USB drive and has no relation with the default browser in the computer.  This ensures that your online activity is not stored in the public computer since you have not used the browser installed on the PC. Click here to learn and get a portable version of Firefox

  

4.     Keep an executable file of Free Commander. It can be found here. Free commander is like a windows manager which gives a detailed layout of the file management of the computer system. The file you want to work with can be opened from Free Commander Window. Most importantly you need to delete the file after you have finished working with it. Take a copy of the file to your pen drive. Next, go to ‘File’ option in FC window then Click ‘Wipe’. This will erase the file from the public computer permanently. Normally deleting and wiping from Free Commander has a difference.  Files deleted from delete option of windows (read OS) can still be recovered by software like Recuva etc. but wiping it from FC makes it unrecoverable. This is achieved by rewriting the memory location of where the file was after it has been deleted. ‘Eraser’ is a software which has been found to do this task more prominently then Free Commander (FC). Eraser can be found here.

5.    If you are following step 3 or even if you’re not doing so, be sure that you use virtual keyboard to type in email, username and password. Don’t stroke the keys on your physical keyboard to input sensitive information. For Windows user, Virtual keyboard can be found at Start-All Programs-Accessories-Ease of Access-On Screen Keyboard. This step can help you in a long way in keeping keyloggers away from your personal information. 

Following the above steps can be beneficial but one need to understand that a person who would want to steal your personal information would target you both socially and technically. Be sure not to divulge any personal information over the phone to any one, not even to the person who introduces you to be your banking employee  or an employee of a website. Be sure that the website you're visiting is really that website because it may be a copy image of the genuine website, made especially for you to reveal personal information. Listen your instincts. Safe Tasking!!

Any queries?? Write to rishiraj.in@gmail.com or comment below.