Author Topic: encrypting and decrypting the signal of a toy RC car  (Read 2766 times)

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Offline khurram6050Topic starter

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encrypting and decrypting the signal of a toy RC car
« on: October 24, 2013, 01:44:35 PM »
i wanted ta ask that if there a way i can use a normal toy RC car in a robotic competition such that i somehow encrypt the signal to be sent by the transmotter and then decrypt after receiving it at the receiver and then do whatever i want to do with it. this way i will not have to make some special frequency transmitter or receiver (i even don't know how to do that), rather i can use the same toy remote and do whatever i want with my signal
all i am trying to achieve is that my receiver acknoledges only my encrypted signals and discards all other signals , even if they are of same frequency
if there is any other way of doing this i would like to know that too
thanks

Offline jwatte

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Re: encrypting and decrypting the signal of a toy RC car
« Reply #1 on: October 24, 2013, 06:41:11 PM »
For toy RC transmitters, the answer is likely "no" unless you can find a transmitter or receiver pair that lets you re-flash the firmware of both ends, and have the tools to develop such firmware.

A much easier way to do this is to use Xbee radio modules. You can set them up to pair such that each end only talks to the given module on the other end. Then use an Arduino or similar on each side to read joystick inputs (transmitting side) and generate servo pulses (receiving side.) Or, if you're driving motor controllers, just drive them directly with serial commands, rather than RC pulses.

Offline Roman505

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Re: encrypting and decrypting the signal of a toy RC car
« Reply #2 on: October 26, 2013, 03:51:38 AM »
You need a different frequency, as jwatte suggested. If you have two signals of the same modulation on the same frequency then they will interfere with one another. Whether one is encrypted or not is irrelevant, because encryption relates to the content rather than the medium. It is the radio interference within specific bandwidths by modulation that matters.

Offline jwatte

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Re: encrypting and decrypting the signal of a toy RC car
« Reply #3 on: October 26, 2013, 03:08:23 PM »
Quote
If you have two signals of the same modulation on the same frequency then they will interfere with one another.

Not strictly true -- various modulation and frequency-sharing/hopping schemes will split the available bandwidth between all comers, rather than make it unusable. WiFi and Xbee both have some of this built in.

Offline Roman505

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Re: encrypting and decrypting the signal of a toy RC car
« Reply #4 on: October 26, 2013, 03:42:34 PM »
I agree. I mentioned modulation. Other forms of bandwidth-sharing involve two transmitters not doing the same thing at the exact same time/place/frequency/phase, one way or another, or making another try if they detect confusion of their signals. There has to be a recognisable signal (not content) difference or an interstice somewhere to get your data through.  :)

 


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