Friday, January 16, 2009

The IMU_Bluetooth_Phone



The picture shows the final form of the IMU. Finally it was able to display the data received from the IMU on a cellphone screen. The best part being that its the cheapest display with built in bluetooth receiver and java programming platform. The standalone bluetooth module cost around 3600 rupees while the phone just costs 3000 rupees. A four member team from RDSO (including their R & D director ) visited the lab yesterday. I reached the lab at 12 pm exactly 5 minutes before the beginning of the presentation. They were pretty glad to see it. They apparently want it to be used in their railway track inspection vehicle. The existing methodology involves "a few engineers who keep gossiping on the inspection vehicle and as soon as they regiter any jerk they stop to check for crack or defects in the track" Using our device the system can be automated. They rather want a GPS module to be combined with the system and the location of the defect be transmitted directly to their control station.
Regarding the detailed discussion they have invited us to RDSO - hoping for some good deals to improve our country. :) In the evening we packaged the kit in a RP made box of the size of matchbox. The IITK logo on the box looked elegant. We gave it to Sir who took it yesterday night itself for demonstration in some aerospace conference in Bangalore.

Thursday, January 15, 2009

The 13th hour !!

Praneeth's and my association with the TMRS lab dates back to the 2nd year summer of 2007. We were looking for some Prof to work under for the summer and one day we see a notice outside the mess, calling mechanical and electrical students with past experience to work on some railway project. Lot of people applied for it including Sankule and Prateek Agarwal. Then there was an interview conducted by Rahul Verma and T.V.K. Gupta Sir in the mission office. Finally four of us were selected. Rahul called us to his room and privately told us that we would be working on ABS and not railway project. It wasn't even 10 days working on it that we came to know that RSS and Jeevan Singh were also in the same project. By the end of two months we finally made a working IMU and a working lab prototype of Anti-lock Braking System for Indian cars. Sir gave us a grand treat. We went to Rave 3 by taxi, had pizza .... then went to Barista and even bought Barista Coffee mugs.
After the sem started we kept visiting the lab to install the ABS on car and soon realised that we would have to make reports after reports. We were pretty disappointed then but RSS kept working. Then came the interesting story:
THE UNMANNED RAILWAY CROSSING PROJECT
Vyas Sir had got a project sanctioned for making an alarm system for unmanned railway crossings in India. RSS got a prototype ready as well. It was nothing but a small metal sensor to be mounted 3 kms from the unmanned crossing with a wireless zigbee transmitter. There was a wireless receiver at the gate end with a powerful audio alarm. RSS had gone home during the Dussehra holidays and I was also in Lucknow. God knows what did Praneeth think and went to the lab one day where people were preparing to welcome the DG, RDSO and demonstrate the project to him. Next morning something went wrong with the circuit and it stopped working. Someone in the lab said that Praneeth was the last person to touch it and he was summoned immediately.
He tried analysing the circuit but not much hope. He called me up. Fortunately I was on my way back to IIT. I was obviously unaware of the urgency of the situation. I reached IIT at 6 in the evening and everything was hot there; someone calling RSS on phone..others convincing Sir . I saw the circuit and cried (dont ask me why). Anyway within half an hour we figured out the detached soldering and fixed it but in the process we had to modify the MCU firmware. The claims were that the circuit had a range of 3 kms. So we were planning to plant external antenna on the module and test it. It was then when the actual hell broke loose. By mistake I touched one of the input wires of the module to 12v and it died :|. That was the only module available which can be got only from Calcutta: I had lost all hopes. Praneeth chatted with their online technical support guide but of no help. Hardly 12 hours were left and the entire blame was to come on me. I cursed myself like hell - first professional presentation and I ruined it. Trivediji and Mohsin Sir were there who kept boosting our moral. If only they could understand the technical catastrophe I had created. We had a tea in the canteen and finally decided that it was useless to hope further with that module. Instead it would be better if we could show him something the next day or at least cook up a nice story. Mohsinji was pretty irritated by that time, "Everything in this lab is done in the 11th HOUR". Suddenly we were reminded that we had used short range zigbee module in the IMU which could be used here. Mohsinji gave us a pair of Zigbee with 700 metres range. I immediately made up a pcb for the circuit and within an hour the alarm began sounding. The good news was told to Sir, though only we knew the consequences. We decided to test the range practically. Trivediji sat with the transmitter at the nursery while we drove with the receiver. It worked till shopping centre - a range of 500 metres. Something was better than nothing. It was already 11 pm by that time. How to improve the range, Ramchanderji started suggesting ideas to put in antenna etc while Praneeth and myself were thinking the same thing: if we could get another zigbee which could be placed in the middle of the transmitter and receiver. It would just act like a dumb hopper which would transmit the data received from transmitter and pass over to receiver on the other side but I literally had no courage to make another pcb for it; which would also require lot of voltage conversion because of different levels of atmega and zigbee.
"What if we just short the RX and TX of a zigbee and power it up?? will it act as a hopper??"
We tried and it worked in the first shot.... wooooow !! Indian jugaad - the ultimate rescuer.
We went out to test the range. This time it worked till Kendriya Vidyalaya - around 1000 metres - cool !! "What if we put another hopper??" :) but we chucked greed and came back to lab.
We all relaxed and went for a peaceful night sleep.


(The picture shows Praneeth with the receiver and on the right is the IMU we made with our very own zigbee :P)
Next day we went to the Kanpur railway station and tested it out. It was giving good enough range. Finally DG came at 9.30 by which time we had played enough with a GPS module and watched a Korean movie on Praneeth's laptop. Vyas Sir, Praneeth and him went by car to the crossing with the receiver while we held the transmitter on the platform. No sooner had the car left than we sent Trivediji with the hopper to the middle of the track. Sir called one of us on cellphone saying " its not sounding...is everything running?" Then he handed the phone to Praneeth. It was ok at my end other than Trivediji's location. I asked him to move further towards them on the track. Within a minute I got call from Sir congratulating us. The DG was very happy. Its not difficult to fool even the most power people in India as far as technical field is concerned, is it ? :D . I forgot to mention that all this time I had my new camera with me. This was just a flavor of the 13th hour cooking; ingredients being common sense and Indian jugaad. They all went home while I stayed back to meet a friend who was passing by on a train.
Recently in August 08, once again we were supposed to demonstrate a derailment detection device to some RDSO officer (because RSS was at home) at a spring factory in Panki and 13th hour work helped again. Its hard to forget the food we had after that in the Orient Resort. It was real fun. Surya had also accompanied us there who was made to write a newspaper report on the entire demonstration.

This is not the end. Even today we are supposed to demonstrate a mobile phone based IMU data plotter through bluetooth. The demonstration is supposed to be given to some RDSO director. Although the basic data is being displayed on Deka's phone but Sir had promised to show him a graph on the phone. Its 5 in the morning and we have absolutely no clue to how is it going to work. Lets see what the thirteenth hour has in store for us this time.