Success Storys

[<hk>]

This thread is about all kinds of your success stories. When think you accomplished something and you want to tell people about it. Maybe you are just happy about something. This is the place to tell everyone about it.

[<hk>]

I just build my own spectrum analyzer. I converted a kids Instant messaging toy into a device giving me a rough overview over the frequency spectrum from 280 MHz to 960 MHz. I can see my weather station(443 MHz) and my car key(817 MHz) on it.
And it costs just 20 Euros. Usually you'd have to pay at least 4 figures for this.

http://ossmann.blogspot.com/2010/03/16- ... lyzer.html

I major in high frequency technology. That's why this is important to me. Now I am writing my own software. Let's see if I can open my car with this.

[>luci<]

congratulations man! I have a r/c helicopter which work in 49,860 mhz, can you send some information to the receiver in the same frecuency to do something that you want?

For example, I like to do a cool in my helicopter but some time I fail. Do you think is posible to setup a comninations of keys to do the trick by itself?

Btw, trying to use that thing on your car control, that might increase the security vulnerability on your car, I dunno, Im just guessing

[<hk>]

congratulations man! I have a r/c helicopter which work in 49,860 mhz, can you send some information to the receiver in the same frecuency to do something that you want?

Do you mean a backchannel from the helicopter to the transmitter?

For example, I like to do a cool in my helicopter but some time I fail. Do you think is posible to setup a comninations of keys to do the trick by itself?

what? You are talking in riddles.

Btw, trying to use that thing on your car control, that might increase the security vulnerability on your car, I dunno, Im just guessing

The key doesn't change. The car doesn't change. I am just trieing to find out how stuff works.

[>luci<]

congratulations man! I have a r/c helicopter which work in 49,860 mhz, can you send some information to the receiver in the same frecuency to do something that you want?

Do you mean a backchannel from the helicopter to the transmitter?

Yes!

For example, I like to do a cool in my helicopter but some time I fail. Do you think is posible to setup a comninations of keys to do the trick by itself?

what? You are talking in riddles.

yea I missed some words XDDDDDD Nvm. Can you use your spectrum analyzer to "control" any device between 280 and 960 mhz?

[<hk>]

Basically you can have a back channel at any frequency that is unused. There are ways to go around it but that requires digital modulation and is expensive. Just use a different frequency. If you just want to transmit a few bytes a second you don't need that much bandwidth. Depending on the modulation, just a few Hz

Can you use your spectrum analyzer to "control" any device between 280 and 960 mhz?

A spectrum analyzer can only receive, not send.
The IM-ME is a toy that can transmit and receive data. So it's possible to send some data back.
However, you don't send 1s and 0s over the RF interface. You have to modulate it onto a carrier wave. This is mostly done by the hardware. There are all different kinds of modulations types. The IM-Me supports a hand full of simple modulations and demodulations like PSK. Those are also used by cheap devices like car keys or wireless door bells. Everything that is made to transmit data very slowly(1 kb/s).

So it's not that simple to demodulate complex datastreams, though. You can't just tune it to 900 MHz and receive GSM data. GSM is way to broadband and uses a modulation my chip doesn't support. You have to be able to tune to the frequency and have the right demodulator build in. I can see the power that is transmitted but it's like listening to a language you don't know. You know it's there but you can't understand nor speak it.

If you have access to the raw RF interface and a fuckton of CPU power(your handy dandy Core i7 is not even close to being fast enough for this) Then your can do the modulation in software. Then you can do everything you want. You are only limited by CPU power.
A device that can do this is called a "software radio" and costs about 1500 $.
With 2 of those you can even demodulate wlan in software. I wish I had the money...