VNC, Powered USB Hub and Squid(?) for BeagleBoard

(A post-dated post in continuation of the attempts on Beagle board )

Once the Ethernet over USB between your System and BeagleBoard is established , it is time to see the BeagleBoard Desktop first hand.

Download and install some VNC utility(Virtual Network Client) TigerVNC in my case.

Launch VNC , and in the window in which it asks for address for VNC Server , enter the IP of BeagleBoard i.e. in our case 192.x.x.x .

Since I still don't have a Powered USB Hub in place for hooking up keyboard or mouse, after connecting the BeagleBoard through VNC, I connect the DVI-D connector to the LCD Monitor.

This arrangement is as good as it gets :)

The only bottom side is that the connection hangs up once we try to transfer a large file.




My USB Hub Attempts

Wanting to connect keyboard and mouse to BeagleBoard, the first attempts to directly plug USB Optical Mouse didn't even power up the LED on the bottom of mouse, signifying the insufficient power being supplied to the Mouse.
To supply enough juice to the Mouse, I made a small PCB , in which the USB connection coming from the BeagleBoard is connected to USB wires of the device as follows:-

USB from BeagleBoard USB of Device Status of the connection

GND GND Connected
D+ D+ Connected
D- D- Connected
Vcc Vcc Not Connected

[ The Vcc of the device is powered through external 5V, and the Vcc from BeagleBoard is left unconnected]

But unfortunately this also does not seems to produce any results apart from displaying the message
Device Not enumerated




Using Squid to provide internet Connectivity to BeagleBoard(?)

Once the connection to Laptop through USB is established, I reasoned that if I could configure my Laptop as a proxy server for the BeagleBoard , then it would be possible to provide Internet connection to BeagleBoard through my Laptop. Thinking on these lines , I found Squid Proxy Server to be a tools to do just that. After investing a lot of time making change in the config file of Squid , Now it seems that Squid can't possibly do this sort of networking , since the Laptop and BeagleBoard are on a seperate network.
Sigh !!Sigh !! , I do have to purchase a USB dongle .


..

Travel Again - Part 1 - Weekend getaway to Gangtok

I believe that sequels are not such a great phenomena. But travel is a issue which is simple and exhaustive enough to allow everyone to pen down his thoughts. So the reboot is destined to start with memoirs of a few recent travels.

Living in Siliguri in northern part of West Bengal has been a pleasant experience. Siliguri is the second largest city in West Bengal and now boasts of a wide array of facilities and amenities. But more importantly it is the gateway to Sikkim and rest of the North East Indian states. Be it road, train or air you have to pass through here to go further ahead, no wonder the whole area is known as Chicken Neck.

I have been to Gangtok a few times before, but thanks to an extended weekend a quick plan was worked out and one fine friday morning our group of four started from Siliguri early in the morning. It  was the beginning of the tourist season so we found the roads in Siliguri in our way all patched up and the Gangtok trip started with a nice drive. After leaving Sevoke behind we were driving on a beautiful road made through the centre of a reserve forest. The quickly passing signs of "Elephants have Right of Way. Do not Obstruct." made us focus out to spot some pachyderm. The dense, tall and varied hues of green trees interspread with colourful flowers mixing a tinge of bright yellow, wonderful violet and pleasant blue on the pastel of green foliage was soothing to the eyes, the cool & slightly moist air all around immediately elevated the mood and spirits from the basic conscious state that we daily wake up with and lives on in our normal day.

Soon the forest cover thinned out and on to one side the river Teesta with its large banks filled with sand and rocks gradually came into view. The sight of numerous trucks taking away the natural bounty of rocks and creating ugly craters all around was an unfortunate sight. Far away in the south the outline of huge barrage on the river could be made out where the river suddenly spreads out occupying all of its wide banks.

After passing a railway crossing we entered in the hills and started our gradual climb on the road. Before and after the railway crossing on both sides of the road were populated by shops catering for people going up and coming down. These shops were in minor ways different from their counterpart of the city and gave an early glimpse of the same which are dotting all along the roads in the mountain state of Sikkim. The drive continued effortlessly with the comforting sight of Teesta on to our right and hills all around covered evenly and extensively with local flora. Looking around we could only see either the road ahead, the greenery around, the sky on top and river below. It didn't took us long to arrive at the famous Coronation Bridge where the NH-31 on which we were travelling is divided into NH-31A & NH-31B. Wiki records says that this arch bridge is almost 75 yrs old. This yellow and pink coloured landmark presents a beautiful photoshoot opportunity for first timers going into Sikkim.  We pushed ahead keeping with our own pace. Another landmark in form of a huge concrete wall spanning from one side of the valley to another was totally out of place in the scenic surrounding and weather. As it turns out this is one of the many hydroelectric project which is harnessing the power of mountain rivers of Sikkim. Continuing ahead on the curving roads with the same scenery only with Teesta filled on the brim due to large amount of water being held back literally by thousands of hands who had worked on the dam. On the way to Rangpo we crossed junction going to Kalimpong thereafter Meli Bazar. Near Meli Bazar is the place where River Teesta coming rushing down south all the way from north most parts of Sikkim is joined by the holy River Rangit. The dark coloured waters of Rangit maintaining its identity for some time downstream and then playfully both the streams become one in appearance and name. This place has a reasonably large sand bank with the whole area considered holy by the local population. From here to Rangpo there are several sites suitable for a picnic spot, the road being near to the river stream and there being lots of space in the valley bottom filled with sand and rocks. This portion of Teesta is also used for providing river rafting facilities. Also slightly ahead an area comes which has a planned plantation of trees. The floor of this planted area was evenly covered with old, withered leaves. This setting presented a unique opportunity worth capturing in a camera. So while not on the way up but next day while returning we let out the shutterbugs and made brief halts at the river bank & in the woods. 

Right in the Woods

The sun was rising up in the horizon and the empty stomachs were wanting a refill of Wei-Wei. From Rangpo crossed over Teesta and after crossing through a check post we were in Sikkim. The road on way to Namchi was under construction at quite a few places, causing jolts and shocks. As we begin our drive up towards Namchi, the weather was hazy otherwise on the way the hill on which Darjeeling is situated is clearly visible and so is the towering icy covered mountain peaks around Mount Kanchenjunga.

Reaching Namchi, the first destination was Namchi Helipad also known as Assangthang. The helipad has an area atleast the size of a football field on a tabletop ridge. The view from this place is amazing, with a clear view of sacred Rangit river meandering around the Namchi hill after coming down from the north and in the east the giant statues of Padmasambhava (the world largest statue of the Buddhist guru) and Lord Shiva statue of Siddheshwar Dham. Enroute we paid our due in a Sai Baba temple. The Sai Baba temple was very nice with large halls and quite well made and neatly decorated with paintings and engravings. The main attraction for us was Siddheshwar Dham. This is a unique pilgrimage destination which has replica of all four Dhams of the country together in addition to the replica of twelve jyotirlinga of Lord Shiva along with a Giant Statue of Lord Shiv. The whole complex was very neatly and beautifully laid out. The beauty of the shrine enhancing its spirituality.  Even in todays world of quick, easy and rapid connectivity it is not easy to travel to the famous temples of India and it was a satisfying experience to pay my sincere prayers to the replica of these sacred shrines. With a bit of spiritual peace and contentment, I had already achieved the satisfaction of this trip. With a quick lunch at the Dham itself our drive continued. 

Lord Shiva at Siddheshwar Dham

Panoramic View of Siddheshwar Dham 

We expected a paucity of time, having departed from Namchi past 2 o'clock in the afternoon we were aiming to hit Gangtok before dark. So the idea of Guru Rinpoche( Padmasambhava) as well as a stop at rock garden was dropped. Our route being to reach Singtam after crossing Damthang. Before long the weather started turning cloudy and almost simultaneously we uncovered large tea garden spanning up and down the sloping mountain sides on which the road was constructed. This made us do a pit stop at a road side tea cafe for a sip of the local organic tea. While the tea brewed in the kettle we ventured through the tea plantation all the while electronically preserving the memories. The tea was fine but the place and the environment was more refreshing than the variety of caffeine served in the cups. These tea gardens are the lone ones in Sikkim producing their own variety of Temi Tea.  

Sikkimese Tea Garden at Temi

Initially we continued our climb up to cross a ridge that separated Teesta valley from the Samdruptse Hill of Namchi, thereafter we gradually descended along the Teesta valley and reached the town of Singtam after crossing  Teesta over a bridge. Now we were deeply inside Sikkim and every aspect of landscape outside reflected a bit of Sikkimese culture- the people, clothes, buildings etc. The way to Gangtok was not much far away now and just by sun-down we were in the limits of Gangtok city. It was an altogether different affair that it took us almost an hour to locate our resting place for the night.

                              

Once we were done resting for sometime, the guys in the group came down straight to business. Well none of us had really visited Sikkim or Gangtok or any such place. But when the whole plan was being worked out there was one point aim of this getaway and that was The Casino. My friends had not been to Casino before and I guess they were too much influenced by the images of swanky, modern casino floors which are huge and offer all kinds of games and options to play and definitely a world class luxurious environment. But the reality was different. Anyways not to break the excitement I let the hopes and dreams be what they were intended to be. So at around 8 in the night we set course to the epicentre of all our hopes. I did try to quietly level the expectations with the reality. But the Hollywood images of Las Vegas Casinos were too deeply engraved. But the reality had to hit and it did. In India only two places have  casinos - Goa and Sikkim. The Casino Mahjong co-located with Mayfair resort is the place for people who believe in their luck working for them. Everything that has a start has an ending and after couple of hours and testing our luck at Slot machine, Black-Jack but mostly Roulette, we were back in our place of accommodation late in the night.Finally the itch of casino was dealt with.

The restful night in Gangtok gave way to a beautiful and lazy morning with clouds slowly drifting in and out of the valley and added with a bit of drizzle now and then. Again it was time for the second most important agenda of the trip, MG road. After navigating through the clean city road which were thoughtfully provided with fenced pedestrian lane. I would describe the feeling of Gangtok city as smart. Definitely not crowded or giving a vibe of confusion or overpowering. It seemed to be quite welcoming though being intriguing. The shops and building being decently constructed and maintained. The people all of which were nicely dressed and seemed fashionable to an extent. The traffic was well controlled and it took us some time to figure out how to go around the place without inviting the wrath of traffic cops. Managed to find a parking spot a wee bit away from MG road. Just in front over there was the ropeway. The ropeway in located around south east side of the city with its ride offering a bird eye view of the city around and below. Again due to early rains in the morning the air was hazy and the view was not at its best. 

Bird's Eye View from Cable Car

A morning View of M G Marg

Next we quickly reached MG road and walked up and down the no-vehicle shopping area. This road is a beauty in itself, encompassing and a reflection of the smartness of city of Gangtok. It is a ritual to have a few clicks and we promptly obliged in earnest. For sometime we checked out a few shops and brought a few souvenirs each. Then we settled comfortable on few of the numerous seats uniformly spread through the road. It was a liberating feeling to be just sitting on a street chair, no worldly worries on mind, breathing cool, refreshing mountain air, just calmly looking at people passing by- some rushing for work, some tourists like us, kids in school dress, shopkeepers, people of all ages, size and gender. The last though equally important thing for us was to satisfy our complaining tummies. Baker's Cafe is a shop which I prefer to have at least one meal while in Gangtok. No question about the nice food, the decor and ambience of this shop is truly global. The shop is aptly decorated with souvenirs from several corners of the globe like a reminder of a bit of flavour of each of these places present in the cuisine of the place. With this our last item on the to-do list got ticked off and a bit after noon we started our return leg of the journey.

Conclusion

This post has been an epic write for a small journey. But probably it was the journey and experiences that was worth penning in every detail. Finally managed to complete a worthwhile post on this blog, with more to follow. 

The end result was an amazing outing with close buddies and we logged Namchi and Gangtok from our to-do list. North Sikkim coming up next. 

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Reboot

Time flies even before you know it. Its been more than 3 years since the last post on this blog and it does not seem such a long time. 

Anyways got a new topic/excuse and motivation to reboot this blog and restart once again. 

Life in Air Force Academy(AFA) - Hyderabad

                                       

Line Up of Kiran Jet Trainer Aircrafts on Tarmac

It was a fine July morning when I found myself standing at the Secunderabad Railway Station in front of a desk with three people sitting under the banner announcing Reporting for Air Force Academy. Got my name checked and they told me to remember the name of squadron as Brar. Outside found a few guys whom I met at SSB or medicals and was please to know that two other guys of my group from SSB were in same Sqn.

Quite a number of Cadet and some parents were standing there soon we guys boarded the bus, a photographer was clicking the pics of the guys and of course the gals present there, so that later we all could see them and make out how funny we were looking then as compared to now, and as a matter of fact one never fails to find how we people looked so funny and casual when we were still civilians( and it would be the other way round for all the normal civil guys when they notice the difference between us).

Soon enough we reached the gates of Air Force Academy(AFA) Dundigal and it was with a sense of huge pride that I looked at the runway and the gate and a feeling that finally I arrived at a worthy enough place which I deserved. The bus moved inside and the occupants of the bus kept their stares fixed at the various aircraft and missiles on display en-route from Annaram Gate to Flight Cadet's Mess(FCM) aka our home for the next one year.

I remember well that it was lightly drizzling and in my astrological beliefs that was a sign of good beginning. Our stuff got offloaded and we moved to Shamiyana for the attendance. After a long wait, we got our luggage checked. The check were to make sure that we were not in possession of a mobile phone or camera or any eatables !! and other superficial stuffs(even personal medication) like that. All these while the things were being done by the Appointments, who are the Senior Term cadets who takes care of the Cadets while they are in FCM, kind of like School Captain.

After a while we got several items issued and our cabin numbers. Life in college can be easily managed without even seeing a water glass, water bottle, hangers, brooms and all some trifle items but not so here, maintaining a living standard of an Officer requires a lot of polishing of the attitude and this was a small beginning.

 

As Juniors(the people in white with ugly haircuts)

Once all the luggage was dumped in the cabin and after acquaintance with the neighbors around the rest of the evening and night passed in having a gala time with old friends from SSB and medical. Since by this time any of the Senior Term cadets have not arrived except for the Appointments, there was nobody to check any junior cadets.

Then from day two to the first week were probably the most boring and disgusting days of my life. There were lot of formalities, kit issue, tailor issue, hair cut, medicals and so on and so forth an endless number of things in which we just have to go to one place and keep standing at-ease and just wait till eternity till everyone got finished and then we march of back to Sqn Office. It was like at the end of every day we used to count that in the whole day we have just done 3-4 things and not even got to sit down once or be in our cabin for more than 5 minutes. The first night muster of the Academy was quite an experience of continuously standing in attention till all the counting was done, report compiled, its checked and rechecked that all are present and Duty Instructor came, report is handed over, he again checks and cross checks and finally goes back.

At the end of first week we could feel that our previous lifestyles have been left far behind, every luxury and privileges that we were used to were taken away. No more were we getting time to be alone as an individual, the only time spend alone was either during study hour or while sleeping after lights-out. The clothes we wore became the simplest a white shirt(with collar and cuff button and no tie) and white trouser(no provision as well as need of a belt, as only the size being fit is worn) for the formal places and white PT kit for games and ragda sessions :).  No dhobi, no orderly and any facility of fruit shop, bar etc etc. It would seem like a POW camp but this is how an individual is broken down of his shells of individuality and made in an person who matters only along with his Sqn.

....

A normal daily routine of junior cadets at the beginning of term used to be like, waking up at between 2-3am depending on the amount of clothes that you have to wash(it is quite difficult to hide any dirt or dust in white clothes) or iron, and then attending a 4am fall-in in which the report never gets compiled and submitted to Sqn Appointment by the allotted time and hence by default all the undergoes a series of push-ups, sit-ups and other doses of early morning exercises. At 5 am there was another fall-in for juniors for daily Drill( that is march past) and we were left sweating from the sqn office just 10 min to 5, to change to drill uniform and report in time. From 5 am after all the junior cadets have came, all the sqns' report compiled and submitted,  then the dreaded round of dress inspection by the appointments and the defaulters caught with dirty clothes, improper ironing and anything major or minor were rounded off to be destined to do some more sweating out in the afternoon and evening in the form of reportings. Then we move on to the Drill Square or Parade ground where Drill Ustads instruct the cadets to perform the parade movements individually and in synch when in a group. Drill is one strenuous exercise, from the outside it appears only few movements are being done but the crispness, speed, timing and intensity of these calculated movements will make you sweat in no time. Anyways its always a treat to the eyes to watch  well executed josh-filled parade movements. We graduate from basic hand drill to parade with rifle in the later part of the training. Left from their we rush back in great hurry, to make good the fall-in time of 0730 with half-an hour to spare for bath, change over uniform and have breakfast. It really amazes now how efficient people become with their time once time becomes precious. In such testing times it helps to have a priority, I for one have highest priority for breakfast in all of this morning chaos. I was willing to take an hour or so of punishment later in the day rather than start the day with empty tummy. Bottom line make your value system and prioritise your task and stick to it. 

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At 0800 another part of the day commences in which cadets of different branches go to their respective faculty for studies in their relevant subject. This probably is the most relaxed part of the day with ample opportunities to relax from the tiredness of the early part of the day, some people keep their eyes and/or ears open for the activities going on in the classes but some simply give up on the efforts. By 2 o'clock in the afternoon we leave for FCM again and after having a more or less unhurried lunch, we come back to our rooms, just to hear in time another round of session for accumulated deeds of the morning or anything pending. By the time we get done with this it it again time for PT and so we proceed for the fall-in routine for the same. PT is a toned down activity compared to the same happening all the time in FCM. We come back by around 6 in the evening and after having a round of eats/tea/cold coffee served in mess office, we again barely have 30 min or so to take bath to clean up from the sweaty, soiled condition of us and our clothes and also get our rooms in Cabin-Cupboard inspection standard for the study period starting from 7 o'clock. Study period is an open door time in which you are supposed to be studying in your neat and tidy room dressed up immaculately in whites/muftis simply meaning white full sleeves shirt & white/grey coloured trousers with or without neck tie. Inspection goes around by an Officer or Sqn Appointment to ensure compliance of the same. End of the study period starts with a call for Dinner, and all the cadets assemble in their sqn office and proceed to Dining Hall together. Then after having food or something else depending on your luck, again a mass gathering of the whole cadet lot of all branch and sqn, a night muster takes place in which everyone is counted, accounted and presented on the parade for inspection. After this the everyone is dispersed for a Lights out time of 2200. But the time in between is again a fun filled activity of some more bit of exercises and couple of minutes before the Lights out time we are left to rest our body for the night. 

Coming back to the room, sleep is a something you don't have to wait for and paying no remembrances to all the good, bad and ugly things of the day, we sleep on like a baby with a clear head and tiring limbs, to soldier on for another day and then another day for the whole duration of the junior term. 

So for the uninitiated, as the saying goes though it would seem contradictory, this whole routine of training is mental rather than physical. People say that if you survive the academy for first 22 days you will make it through 22 weeks. 

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Life in AFA(Air Force Academy ) - pre reporting

After almost 9 month long process of CDS Written Exam, Selection Board at 1 AFSB and Medical Checkup at AFCME , the path to AFA was now clear.

It was just a formality but after the long and patient wait for the merit list of CDSE was over, the result was declared by UPSC. It was a really nice surprise to find my name on the top of the merit list. WOW !!!
So I was off to a good start. But as it happens with all of us everytime, once you have finished something a worry of the future starts to occupy your mind and in my case I started wondering if I could maintain my steam and will I be good enough to be selected for Fighter Stream after Trifurcation in the Academy.

The answer to this lied almost 1 year in future. To ease any worries I started off with a routine of daily morning running and other exercises to get in shape. Now as my bad luck would have it I found out the really hard and painful way that in my circumstances its better to avoid joining a Gym and more doing Dead-Lift without proper care. This caused me to have symptoms of hernia(or so I thought) and my subsequent lingering worries were not settled down till a Medical Examination in the Academy.




I am being so close to realizing a dream of a life time. I am sure life will rise to a different gear once the training start. Training in AFA will bring across several anecdotes and definitely a lot of memories which I will want to remember.

But the disappointing fact is that there is hardly any first person account which one comes across about life of a Flight Cadet in AFA. The purpose of this series will be to fill this gap, so that a lot of dreamers like me can know more about flying training in IAF.

Before I finish this post, I should mention one more incident.
Once I got through medicals, I went to a retired Maj. Gen. who was a faculty in my college, to get his advice on how to do well in Service. He had some gems of experience to recount.
He told me that in Defence Services a person is quite often identified by the company of people he is into. Like if you hang around with geeks you will be labeled as a geek similarly if you hang around with people having questionable incidences to their name, so will people think you to be. And in Service like Indian Airforce the size is not so big and your reputation, both good and bad, travels far and wide.

Another of his suggestion was that the Defence Services are such that they require a certain set of qualities and requirement and the training and subsequent service makes sure that you inculcate those qualities and the things in you which are not desirable gets filtered out. So one should always take care because we as a cadet and later as Officers will be judged all the time for the OLQs.

Airforce Medical checkup at AFCME

People clearing AFSB (Airforce Selection Board) are next send to AFCME i.e. Airforce Central Medical Establishment, New Delhi for a detailed medical checkup to certify that they are medically fit to discharge their duties in Indian Air Force. All different categories of candidate for IAF ie Flying Branch, Technical Entry and Ground Duty have the complete checkup at this venue. Apart from this this establishment is also the place where DGCA (Directorate General of Civil Aviation) send civilian pilots to have their medical fitness certificate issued or renewed.

AFCME is situated in the beautiful and very neatly maintained Western Air Command(WAC), Subroto Park which is located near to Dhaula Kuan. Except for Dental checkup , all other test, diagnostics and measurments are done in AFCME itself. For this its has several departments like Pathology(with the lab facilities), ENT, Radiology, Eyes, Ultrasound, Anthropology, Cardiac etc.

For the Airforce candidates the process is usually 4 day long. On our first day of arrival the business of the day started at 8:00 am with us filling a couple of forms and other necessary formalities. As usual these form filling take a lot of time and it was almost 11am by the time we were done.
Now the funny thing was that we were specifically told to come empty stomach for the tests otherwise it will take a day more. So there we were all fasting on empty stomach. and it turns out that now a days at AFCME there are no blood test done on first day so no need of the fasting(which b.t.w. sort of triggered a sinus pain in my eye, that too during the medical. what an irony !!!).
After the formalities we were send for the dental checkup which is done at a separate premise. In the dental clinic there were quite a few patients waiting for the doctors, so it took us around 3 hour time for the dental checkup to be done. Dental is usually straight forward affair and unless you have a decaying stuff up your jaws , its a clear affair. Though it is advised that you get teeth scaling done and take care of the decays or caries. In our group two guys were send to see doctor to get their nicotine marks removed.Since it became quite late so this was the only thing that was done on the first day.
I found that in almost all department and all the doctors were hard pressed with the load of the candidates, the civilian pilots and the patients. Its really a tough job for them to keep on doing their job without any mistakes or omissions.

Our lodging was in the Officers Mess and it was so tiring and hot day after getting the meal at 3 pm that for next three hours we slept deeply in the cozy dorms.

The next day again we reported at 7:30 am empty stomach and then our Chest measurement and Height and Weight measurements were taken. There is a height-weight-age chart for the candidates and its is strongly advised to get your tummy measure up to the numbers, Though the authorities give a lot of relaxation on these count. After this we were send to the pathology lab for Blood and Urine Tests. Next on card was the Ultrasound test in which abdomen, liver etc were checked if these parts were normal and to check there are no abnormal things like kidney stones and abnormal size of internal organs. Next we had Radiology in which around 5-6 X-Rays were taken of chest, Spine, Skull etc. Some of the people who had a large angle in the bones of the elbow had elbow X-ray done to determine that angle.After this we quickly had a couple of test one after another like ECG, Anthropological measurement(sitting height, leg length, thigh length and ENT.
For Ear they check for ear wax after that they apply a varying pressure to the ear and the machine generate a plot, it seemed like this test checks how the ear drum behaves in changing pressure. Then the Audio-metric test was done in which there is a headphone through which a few very faint beeps of different frequencies are emitted first in the left ear then in the right, on hearing each beep you have to press the button.The rest of the test of nose is basically one in which the doctor inserts a thong in your nose to check for DNS.
The last thing of the day was a basic test of the eyes in which we were to read a chart about 6mtrs away, a book of color blindness. After this we wore a setup with possibly a polarized lens and a light source was shined which caused a vertical line and a dot to appear.

The next day started with the detail checkup of eyes.Again this time the Medical Officer one by one made us read the Alphabet chart and the color blindness book.Next our eyes were dilated and something was checked by the doctor.
The results of ECG had come and in some cases there were doubts so two extra test 2D Color Doppler ECG and TMT or stress test was performed. In TMT I had to run for 15 minutes on a treadmill while the ECG machine was taking the reading continuously. The 2D Color Doppler ECG was similar to Ultrasound but only it was being done for Heart. Last but not the least we had surgical checkup in which different things like piles,hernia, flat foot , knocked knees etc are checked. Well this test requires you to divest of your clothes, it would seem funny , but actually this all feeling vanishes as soon as you are being checked.

So since we were a bit late our conference was scheduled for the next day. All the files of the candidates were compiled, completed and all the test results were included in the dossier.At last when all the files were completed , we were sent to the President of AFCME, who called us one by one and declared the results which was either you are medically fit to fly or whatever problem was found it was told.

In our group some of the problem which caused them to be declared TR(temporary unfit) were fracture in spine, anemia, too much angle in elbow, eyes sight problem. Since in every case of TR you are given an opportunity to appear before an Appeal Board. In this case you have to submit application for Appeal to Air HQ and then in a week or so you get the date to appear for the Appeal Board in Army R& R Hospital.

So once I was done with the Medical Board, now all is done for joining AFA.

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Since lot of queries have been coming regarding individual medical conditions and suitability of these for IAF medical selection, but I am not a medical professional hence there will not much guidance I will be able to provide on the same.
However as a reference some of the links that you may go through to clarify some of your doubts are mentioned below.


General Physical Standards
http://www.careerairforce.nic.in/index1.asp?lid=48&ls_id=113&level=3&lang=1&pid=61

Additional Medical Standards for Flying Branch
http://www.careerairforce.nic.in/index1.asp?lang=1&ls_id=124&lid=87&level=3&pid=61 


A detailed list of probably all the applicable medical standards.
http://dgcamedicals.in/IAFMedstd.htm

PWM generation in BeagleBoard

My primary interest to make a robot centred around BeagleBoard is incomplete without generating PWMs to control DC motors and Servos. Since Beagleboard has all what it takes to make a robot, I am not going to be bothered to have a microcontroller to aid Beagleboard.

My requirement is like this - say an image processing algorithm is running on Beagleboard, and at end of every iteration I want to update the speed of motors by changing the PWM values. In the meantime when the Vision algorithm is running, the board should keep on generating the PWM until it's value is changed.

It started with searching the community for info and this post is quite helpful. this one also is quite helpful. When I first tried all sort of permutations and combinations according to these information, it just didn't work. The file in which we are supposed to write the values like direction, value would give no write excess error. This problem was due to drivers not loaded i.e. this problem got solved when we compiled a new kernel with drivers of TPS320* which handles these IO functionalities.

Now the basic checks like making a pin high or low starts to work. To make a code to suits the above requirement, we went ahead with multi-threading. one thing to just remind here is that, in Linux these port operations are done through writing and reading appropriate files.

So here are the two files new_main.c and waveform.c

new_main.c


#include < stdio.h >
#include < string.h >
#include < stdlib.h >
#include < pthread.h >
#include < time.h >
#include < fcntl.h >
#include < sys types.h="" >
#include < sys stat.h="" >
#include"waveform.c"

time_info pwm_times;
time_info pwm_times2;

int main()
{
    int i=0,j,k,l;

    pthread_t threadid;
    pthread_t threadid2;   

    pwm_times.time_h=0;
    pwm_times.time_l=0;

    pwm_times2.time_h=0;
    pwm_times2.time_l=0;

    pthread_create(&threadid,NULL,pwm,(void*)&pwm_times);
    pthread_create(&threadid2,NULL,pwm2,(void*)&pwm_times2);
    while(1)   
    {
        for(l=0;l<1000;l++)
        {

          // Your main code runs here

            for(j=0;j<1000;j++)
            {
                for(i=0;i<1000;i++)
                {}
            }
           // Your code ends here

           // Update values of PWM
            pwm_times.time_h=(300000+l*1000);
            pwm_times.time_l=(300000-l*1000);

            pwm_times2.time_h=(600000-l*1000);
            pwm_times2.time_l=(600000+l*1000);
        }
    }
}


In the above code, in new_code.c the main algorithm will be running in place of the three nested for loops.
We have created two threads one for each pwm, and created a structure having parameters time_h and time_l denoting high time and low time. Whenever we want to change the value of PWM we change the value of these two parameters.


Once each iteration of the algorithm completes, we change the value of time_h and time_l for both the PWMs.
   

waveform.c

#include < stdio.h >
#include < pthread.h >
#include < time.h >
#include < fcntl.h >
#include < sys/types.h >
#include < sys/stat.h >

typedef struct
{
    long int time_h;
    long int time_l;
}time_info;


void *pwm(void* pwm_times)
{
    FILE *fs;
    int i=0;
    char ch;
    struct timespec pwm_delay;   
    time_info *pwm_ptr=(time_info*)pwm_times;

    fs=fopen("/sys/class/gpio/gpio168/value","w");
    while(1)   
    {   
        fputc('0',fs);
        fgetc(fs);
        pwm_delay.tv_sec=0;
        pwm_delay.tv_nsec=pwm_ptr->time_l;
        nanosleep(&pwm_delay,NULL);   
           
        fputc('1',fs);
        fgetc(fs);     
        pwm_delay.tv_sec=0;
        pwm_delay.tv_nsec=pwm_ptr->time_h;
        nanosleep(&pwm_delay,NULL);     
    }
    fclose(fs);
}

void *pwm2(void* pwm_times2)
{
    FILE *fs;
    int i=0;
    char ch;
    struct timespec pwm_delay;   
    time_info *pwm_ptr=(time_info*)pwm_times2;

    fs=fopen("/sys/class/gpio/gpio183/value","w");
    while(1)   
    {   
        fputc('0',fs);
        fgetc(fs);
        pwm_delay.tv_sec=0;
        pwm_delay.tv_nsec=pwm_ptr->time_l;
        nanosleep(&pwm_delay,NULL);   
           
        fputc('1',fs);
        fgetc(fs);     
        pwm_delay.tv_sec=0;
        pwm_delay.tv_nsec=pwm_ptr->time_h;
        nanosleep(&pwm_delay,NULL);     
    }
    fclose(fs);
}


in waveform.c we perform the toggling of pin ON-OFF manually in the code by writing to the file named value. [Beware that before even executing the program you have to do some initialisation manually which have not been done in code, these are mentioned at the end]

Since these are multithreaded files the compilation is doen by
gcc new_main.c -lpthread

Initialisation needed Before Executing
You need to do the following things:-
1. Create directory for your IO pin/s
2. Set its direction (as output in our case)

For 1st go to the directory /sys/class/gpio . In here issue the command
echo "168" > export

this will create the directory gpio168, giving you access to GPIO168 which is pin number 24, according to RevC3. Similarly do the same for GPIO183 which is pin number 23.

Now for step 2, go to the directory gpio168 and issue command
echo "out" > direction

this declares the GPIO168 as output pin.
Do the same with GPIO183.

Now your pin no 23 and 24 are ready to generate the PWM according to the code. The waveform that you should get is dutycycle changing from 50% to 100% in one pin and from 50% to 0% in other pin.

Now once the PWM are up, we need an interfacing circuit to connect there 1.8V waveform to motor drivers like L293D. So here we can use Optoisolator like MCT2 etc.

Obviously there might be other better methods to use the in-built PWM functionality, but I am still not conversant with them.

This Post possibly will be the last post on Beagleboard and related Tech. topics, since a different line of work awaits me.