Yes thats basically what I was saying extending the range form 10cm to a region close to within a meter.
From what im reading right now.its a helluva of tough job!I guess im goona have to do loads more of research before i can fully commit myself to this project.If you have any materail you recommend,id be very grateful..
thnx,,really appreciate it bro!

13.56MHz is the standard passive CSC. Touch'nGo is utilising Mi-Fare1 standard, which is same freq. The standard read/write distance is 1-5cm only in read world application. 10cm is in lab/development testing only.

To increase your reading range to 1m, as stated earlier, you need special design of the tag antenna and placement. i.e. distance it from object it stick onto. Also the type and material it sticks on, and whether it can act to re-bound the freq signal.

2nd, the antenna of the tag has to be redesign/bigger, in order to be able to power it up from a distance.

3rd, is to have a more powerful reader, and to narrow down the width of the transmission angle. e.g. from wide 60 degrees maybe down to 20 degrees.

Note also, whether for commercial / prototype, you may need to comply with MCMC standards, I think is 2W if I'm not mistaken. Anything higher, go for type approval testing. Hence, this will limit option #3, the power of the reader.

Hence, frankly, to do 1m reading at 13.56MHz, complying with MCMC and with some 99% read rate and accuracy, I think it is quite impossible to achieve now. If you manage to hit 99.99%, you can market out your product (seriously).

I see youtr point quite clearly,guess im gonna have to just go with designing an RFID based asset monitoring system with the usual read range of about 10cm,i.e similar to what is used in some college libraries,..for this i guess i can use read onyl tags if i aint mistaken,right?thnx

Hey guys! I dno im in the right thread or not. But I rili nid help as a newbie
I'm a foundation engineering student. And I need help where to get materials or building kit for a model car using pulley and solar powered. Anyone can tell me where to find all these stuff in KL/Selangor? Which shop if u guys noe?
Thanks

need help guys....

I am not very technical in this....so here goes---- in a circuit how do I lower the 5V output to a 3V input..I am trying to use the USB from a PC which I was told is 5V, to light up few LEDs....I think the LED is 3V .

I was told to use a resistor to bring down the voltage. Any particular resistor if I were to ask at Jalan Pasar?

Thanks.

Just placed an order & payment for a Arduino Duemilanove 328 to your site..

Stanley

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Added on September 5, 2010, 6:48 pmUse this calculator ..

http://ledz.com/?p=zz.led.resistor.calculator

The USB current is around 100mA to 500mA...

Buy more range of resistors to be able to adjust the brightness of the LED...




This post has been edited by stan001: Sep 5 2010, 06:48 PM

You need to know the current requirement of the LED you're using. That's usually difficult without it's datasheet.
For standard 5mm diode and 5v supply, the usual resistor values used are 220R, 330R or 470R. 1kR is fine too. Higher value is always fine as long as the brightness is enough for your application, and probably let the LED live longer too. Note 3v forward voltage drop is on the high side, usually it's between 1v to 2v.
Or if you want to experiment, get a 1kR trimpot to play with. Just don't short it.

thanks a lot for the info.. ..best to buy a few to try I guess....

Hi stan001 thanks for the order. Send it already. by the time I'm typing this you should
already receive it.

Anybody need Teensy++

Dear Azmax,

I was away yesterday, came back today, check my mailbox and the Pos Ekspres package Arduino board was there.. just d/l the IDE and tested it... everything is working fine...

Thanks

What is Teensy++ ???

Stanley

Been playing around with both the Arduino and MSP430 launchpad from TI and are impressed by both!!

Both are programmed in C although it is possible to program the MSP430 in ASS-embly. But i won't bother with assembly as it is a pain in the rear.
Arduino programming is very straigh forward! Frankly I'm amazed at how easy it is. Most probably, you don't need to start coding from scratch as there is tons of code examples available out there to modify to you own taste.
MSP430 in other hand, require much steeper learning curve. Let's just do an example of the two initiating digital pin mode:

Arduino: pinMode(pin, OUTPUT);
MSP430: P1DIR |= 0x40;

See, Arduino is much easier to understand than the equivalent MSP430.

The MSP430 specialty is the very low power mode. It use 3.3V and consume very little current as it can go on really slow operating frequency.
But for power and simplicity, it simply can't beat Arduino.

Good comparision... I never used other microcontrollers before but I know it is pretty difficult to program and only ppl in this industry ( non hobbyist ) know how to do it bcos it is their job... and it is usually program to do a specific task without much re-programming to the MCU.

I read about the trend of IC going to 3.3V from 5V, is that due to the low power devices ?

The MSP430 code remind me of doing assembly lang... very efficient and talk to the h/w directly but so so difficult to read and understand the codes.. must think like a machine instead of a human... haha

I think Arduino open up a whole new market and communities of hobbyist and fashion designer ( very little programming or electronic knowledge ) to use the microcontroller with minimal barrier to entry nd learning curve..

Hope to see more people picking up Arduino and we can have a large community of suppliers, designers, hobbyist and useful products made out of Arduino

---

Added on October 7, 2010, 1:08 pmAnyone know which shop does sell mini breadboard in Jalan Pasar ?

I lot of them sells the regular size but I am looking for a half size breadboard..

Thanks


This post has been edited by stan001: Oct 7 2010, 01:08 PM

ive been reading a bit on robotics and have found that there are amateur hobbyists that will build robots to their imaginations and such and being an enthusiast programmer myself, i would like to get started in this hobby, but im trying nt to spend too much on a kit or something similar, my fren got a lego nxt if im not mistaken which costed approx 1k hmm any other cheaper alternatives ah?

I'm not into robotics but a lot of hobbyist use Arduino as the brain of the simple robot to control the motors, servos, install sensors to track distance, light or perhaps have wireless RF / Bluebooth / Xbee to send and receive signals from the robot..

Do checkout http://www.homebrew-tech.com/ as they might actually have stocks for Arduino or some motors & sensors to get started..

The programming codes are very C like..

If you know electronics, you can buy the parts and wire it up yrself or if you are not into DIY, you can just buy the functional shield ( module on top of the Arduino ) and mount it to the robot..

I wrote a blog for Arduino beginners, ppl like little or no knowledge in electronics too : http://arduino-for-beginners.blogspot.com/

Stanley! Thanks for promoting my website!

For the rest of you guys. Just to highlight that I am doing a bulk with super duper promotion at the moment.

I am experimenting with additional price discount modifier. Those who buy Official Arduino product with 2 or more quantity for the same item. Will get more discount for each.

For instance buying 2 Arduino Duemilanove and you get each of them at RM95 (RM100 - RM5). Buying any third item, and you get each of them at RM88 (RM93 -RM5). First time ever an Arduino board is at that magical double 8 price!

How can I offer this kind of price? Simple, as an official distributor for Arduino official product and listed on Arduino Team Buy Page. I have a routine shipment direct from the Italian team. By joining this bulk you guys are actually piggy back on this shipment that usually have a lot of surplus weight. I pay the same shipping cost but with more stuff. The saving is pass direct to the loyal or future customer. Piece of cake!

Visit my Bulk Thread thread for more info or read this post.

Your feedback, participation and support is really appreciated.

Hi guys, Im new here..juz a quick question
is there any portable 24V power supply?? cos i nid it to drive the motors of my robot...

Long time no post here.

What do you mean by "portable"? No wires connected to mains (AC)?
That means you need some kind of power sources e.g. batteries.
Gotta know how much voltage and current is needed, battery may not be viable or economical though.

Portable power supply == battery ??

yeah....i nid a battery...is there any 24V battery available??
or should i juz use 2 12V batteries?

Yes 24V batteries exists.
For e.g. lead acid battery used by large trucks and trailers but these are usually too heavy for robots.
For high current draw, you can also opt for lithium polymer or NiMH batteries used for hobbyist RC airplanes and helicopters. You'll need to connect several of these in series to get 24V.
And you'll have to know what's the total power/current your motors required before making your selection.