August 13 ,2008

Came home and saw the door locked, opened it and saw a small box with lappteck written on, I knew what was in it. I called up abhishek to tell, that the touch screens have been delivered, and how to pay for them. I called up Poornashree to see if something can be done. Finally gave the bill to my dad. Inside the box were 2 4-wire resistive touch screens. . Waiting for monday to use them.

29 July 2008, What has been done till now?

The search for the BE project started during our semester 6 exams ifself. Abhishek and me used to search in the 4 days we got in between the exams.

We started with AVRfreaks.net. We wanted to build something interesting, innovative, useful which explores various new components, something which after seeing everyone will go “Wow! This is great”.

With this criterion in mind, we got a site of cornell university where all the students had put up their projects. The specialty of this site is that all the projects listed are made using the ATmega series of Atmel micro controllers, our favorite. Though the average level of these project is quite high for Mumbai University students, we shortlisted 3-4 projects of our interest like bar code scanner, hand writing recognition, search bot etc. We finally made the choice “Touch screen controlled wireless car”. This day was, I think within the first week of our vacation.

Then the main headache started with the touch screen. We searched and searched and again searched for one full week trying to estimate its cost. The project on cornell university had used a Palm mobile p128 touch screen and was available on eBay for $18, But we were totally new to this concept of “touch screen”. So we didn’t want to yse a device that does everything in background. Frankly speaking $18 was too huge amount to be invested for one part of the project.

We continued our search and I found a site where a touch screen was being sold for $25. Another great shock. So we intensified the search , now we searched for manufacturers of touch screen to get the best possible deal, a free sample

I emailed more than 18 companies and Abhishek contacted 5 companies. Only 5-6 companies replied of which, only 2-3 were of any use to us as others couldn’t supply individual units or didn’t produce small size touch screens. The ones useful didn’t replied our further queries, so we were a bit disappointing since we were still at level 0.

Simultaneously we searched for Touch screen controllers to simplify the job of interfacing a touch screen. We got a lot of search results, but the one that seemed very simple to use and had many features was TSC2005 from TEXAS Instruments. We had heard that Texas provides free samples of any chips. So Abhishek hurriedly registered at its site myTI.com and ordered a sample of the IC on 3rd July. I also joined and ordered the same IC on the same day.

Then the great joke happened. I received a courier by FedEx. I signed on a touch screen device of the courier man. The details of this thing are HERE. We later contacted Prabhu sir if anything could be done with the IC. But we stopped thinking about the controller as of now.

One week before the college started , we started searching a graphical LCD to be used behind the touch screen. We inquired into CHIP, Visha and other stores at lamington road , where we got the price to be in the range of 660 – 775Rs. Poornashree helped to get the library for KS0108 controller used in most of the chinese made LCDs. But the library was for avr-gcc. Later Abhishek went to lamington yesterday and confirmed the controller used is T6369.We made the stepper driver circuit using the L293D at my place. Thats all as of now.