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Thread: rf transmission

  1. #1

    Default rf transmission

    hi,i want to build a simple bot with four motors and which i can control wirelessly using RF transmission holding a remote control in my hand.i do not want to use microcontrollers.can somebody show me some circuit diagrams and more detailed info on this topic as i am a total noob in this field.its really urgent .please do reply ASAP.i read somewhere that we have to use HT12E/D
    can somebody throw light on this.thanks in advance

  2. #2
    Senior Member Cyborg pkshima's Avatar
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    Default Re: rf transmission

    Quote Originally Posted by 007roy
    can somebody throw light on this.thanks in advance
    Yes that somebody is google.

    That said, there is nothing you 'have to' use. For example you can use dtmf chips UM91214B and MT8870 along with cheaply available FM mic and fm receiver kit to make the thing. simple and works great.

  3. #3

    Default no success

    hey.i have bought the following
    HT12E/D
    ASK TX/RX pair 434MHz
    and i tried following the circuits in all these sites
    http://www.thinklabs.in/resources/?p=50
    http://www.multyremotes.com/four-channel-ASK-remote.htm
    and quite a few more.but i have not got any success
    just few times the valid transmission LED was glowing that too when i connected the mulitmeter to that pin and after that it is not glowing
    i tried whatever i could and gave up.can somebody please help me with the correct circuit diagram and if these diagrams are correct then can you tell me where lies my fault.dont tell me about wrong pin configurations because i have checked all the connections about twenty times.i heard that you also have to adjust baud rates.no idea about this concept.and will changing the resistor values across the oscillator pins hamper frequency.i am anyways using 1Mohm for transmitter and 51k ohm for reciever and my whole circuit is one single breadboard and running on 5V.both the circuits are very close to each other.do i still need a antenna.somebody please guide me and be my mentor.thanks a lot in advance.whoever replies to my doubts will really help me and solve all my problems.thanks again[/url]

  4. #4
    Senior Member Cyborg pkshima's Avatar
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    Default

    One of the things you could try is using fresh batteries.
    Second try to give the RF modules higher voltage than 5 volts.
    I have two pairs one works fine with 5 v but the other works at more than 6 volts or so. Check their datasheet if any.

    I am afraid I have very little experience with RF modules. I plan to some day write manchester encoding/decoding routines in C to be able to make good use of them.

    BTW, if its not too late, do consider bypassing the whole microcontroler stuff and RF modules if you dont have much experience. If all you want to build is a radio remote controlled bot, then you can use DTMF (audio) tones to communicate. Thats what I did in by first bot.

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