next topic »

[on:]

Hello there,

I performed a quick search on the forum about wireless transmission but could'nt find a solution to my needs. I am total newbie in radio frequency and would be very interested in having your opinion.

I am trying to create a dozen of modules that can wirelessly send their ID to a single Arduino board.
I'm looking for a very low tech and cheap solution that can be embedded in small tetrahedrons.

I would like to be able to put these tetrahedrons on any wall and to know which one are active (meaning, emitting their ID), maybe by using a conductive painting or surface.

I know RFID could be used in this project but I would rather prefer not to instrument the wall with a reader.

Thanks for your hints!

[Reply #1 on:]

How big are these tetrahedrons? Zigbee modules might be a bit of overkill but they are low voltage (3v) and can be remotely programmed and you can put them into low energy states such that they switch on, transmit their bits of data and then switch off again conserving energy.

cheers
ajfisher

[Reply #2 on:]

Thanks for your reply!

Tetrahedrons are about 5cm.

Zigbee modules would be small enough but maybe a little bit expensive.

[Reply #3 on:]

As Crossroad posts in another subject.

this module can usefull for you.

http://www.ohglrf.com/upload/2010330191534162_0.pdf

But there are only 8 differents frequency.

but in thsi pdf we can read :

Carrier frequency: 433MHz, also capable of 868/915/2400/5600MHz.

So from with a combination of 433 and 868 Mhz modules, you can achieve your job. But this implies one thing.

The main arduino that will collect the datas must get 2 RF modules (one that deals with 433Mhz and one that deals with 868Mhz). So from an Arduino Mega will be the best choice as it gets 4 serial ports.

May be this way of doing things is not the most elegant but it can works.

Sure that people in this magnific forum will have other great ideas about your project.

Best Regards

[Reply #4 on:]

Have a look an Jeenodes. http://jeelabs.com/products/jeenode

______
Rob

[Reply #5 on:]

Thanks Grag38 + Graynomad.

Jeenode sounds like a very good option.