Designing a PCB

One of the things I wanna learn this month is to build hardware circuit on a pcb with commercial CAD software which are used to build circuits. The coolest thing about PCB software is that you can actually simulate a circuit without making the real hardware circuit. and it helps you analyze faults before you produce your circuit. I had designed a small PCB for SPI interface of an MMC/ SD card to a microcontroller. It was easy to design as there was no special circuitry needed for except for a few optional pull up resisters which should be used if the BUS is in open drain mode. If it is in push pull mode then there is no need of using pull up resistors. It all depends on which microcontroller we are using. If we are using a low end microcontroller like a PIC which is cheap we must use a Pull up on the data lines of the SPI bus. On the other hand if we use a High end microcontroller, it may provide options so that we dont need pull-ups. Overall PCB design a must learn thingy if you are into hardware and serious about becoming a hardware engineer.

Good and bad procrastination

Recently I was reading slashdot and came acrross an article called Good and bad procrastination, written by Paul Graham. It is an interesting article about procrastination and which types of procrastination is better for us. I decided that I would stop procrastinationg and if I do it would be good procrastination. Paul graham has written many good articles like How to generate wealth, How to start a startup which are worth reading.

Slashdot is a nice site which has lot of interesting articles written by geeks and computing nerds.
If you have any interest in science or techology, you will love it.

Startrek and science fiction

I was disappointed when star trek enterprise came to a sudden end. The 3rd season was interesting.. inspite of of the first and second seasons which were lackluster in their performance.
The fourth season was boring. There wasn’t anything interesting… after the Xindi encounter is settled. Having been a trekkie for quite a long time., I’d say that Enterprise was the least popular of all series… except for the arc like third season.. where captain archer and his crew.. track down the aliens ( the xindi) who are going to destroy earth…. after a group of interdimensional species show the xindi. that earth is going to destroy their home world in 400 years.. With the help of a time traveller, Archer ( scott bakula) goes to the future.. where the federation of planets engage the interdimesional beings.. and… tries to convince the…. xindi.. that earth is not going to attack them.. After a lot of drama.. earth “befriends” the aliens in the delphic expanse… which is 2000 light years from earth…

Some of my favorite episodes in Enterprise are:
Carbon creek, Proving ground, The Communicator, Future Tense, First flight, Similitude, Azati prime

The startrek original series is one of the best scifi TV series ever… with interesting theories… or ideas.. Some of my favorite episodes are:

The enemy within, The changeling, Plato’s stepchildren, Squire of gothos, The arena , The omega glory, Where no man has gone before, Mirror Mirror, By any other name, All our yesterdays, Return to tomorrow, Amok Time

Science fiction is an interesting thing.. I think that science.. fiction.. serves as an inspiration for us.. to achieve or invent new things.. although I dont expect rockets which can go at warp speed.. we might disover the secrets of nature in time….. which might help the human civilization to become sophisticated. We might ask questions.. which we would have never thought of asking.. before or after we find any answers in nature..

Embedded File system

Storing data onto flash cards has become “the ” technology of recent times. If you own a cell phone or a digital camera you must have seen compact memory cards which store your files ( images or ringtones, data) on your gadgets. They are called flash cards and are new types of data devices unlike our conventional storage devices like the IDE hard drives of the 80’s and 90’s. If you can find a way to store data onto these devices, you can actually use them for making a product which is worth something in the market. For example, Robots can log data from analog sensors and record them onto a MMC/SD/compact flash card using a file system so that you can analyze that data on a computer running windows or Linux. This is useful in rescue robotics where it is hazardous for humans to enter and log the physical parameters of the environment. Robots can do this without much difficulty. Fat 16 is the standard for industrial devices which store data onto sd / MMC cards. Be it video, digital cameras or cellphones. Fat 16 is the most economical and widely used format to store data onto memory devices and hence is used as a standard embedded file system. I came across many examples of Fat 16 one of which was published in a magazine called circuitcellar, a magazine for the atmel AVR micrcontroller. You can get the source code from the ftp server of circuitcellar. The article can be purchased from them for a modest fee.

Nand Flash memory

Nand Flash memory is the latest technology which is happenning recently. We can see such types of memory devices in an I-pod nano from apple. They are compact and very efficient have better write cycle ratio and are way better than hard drives. This is an important issue when it comeos to space.. as in cellphones, digital cameras or robots where it is good to have a memory device which is smaller and lightweight. Samsung is going to launch nand flash memories upto 16gb by the end of 2006. You can read a general introduction to nonvolatile memory here : http://aplawrence.com/Makwana/nonvolmem.html

Also there is an application note from freescale ( motorola ) which is titled, “Non-volatile memory overview”. The freescale website has the pdf file of the article.

I read somewhere that there are 1 inch harddrives on the market to be used in cell phones or digital cameras which can store upto 6 gb of data. This is interesting.. cause the smallest harddrives were about 1.8 inch in size, last year. Toshiba and seagate are manufacturing these devices along with sony.