I need a circuit for rc car transmitter and reciever

Discussion in 'The Projects Forum' started by Stiven97lol, Jan 25, 2011.

  1. Stiven97lol

    Stiven97lol Thread Starter New Member

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    So in my school there is a science fair and I want to build an rc car. I got everything figured out exept for transmitter and the receiver. Can someone post a link or something that tells you how to make transmitter and receiver. I want my car to go forwards, backwards, right and left and also have different lights. so its like 6-8 different commands or I don't know what they are called. It is my first time building an rc car so please help
  2. Kermit2

    Kermit2 Well-Known Member

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  3. jonnyphenomenon

    jonnyphenomenon Active Member

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    a couple years back I built a remote controllable "annoyatron" that I could use to emit shrill beeps, flash lights, etc. it could even be connected to a PC to powerup or shut it down if I wanted.

    I used a kit I got from rentron.com which included everything I needed for a 4 button remote control, and a 4 output receiver.
    http://www.rentron.com/remote_control/R8_4BIT.htm
    this includes the tws-43a4 transmitter module, RWS-434 receiver module and all sorts of other bits needed for the circuit.

    datasheet here: http://www.rentron.com/remote_control/R-8Px.pdf

    I designed and etched my own PCB for the compact controller with a home PCB etching kit, and packed it into a small box little larger than a 9v battery.
    [​IMG]


    here is the front view of the remote control and the receiver on the proto board in the background. I installed an off switch into the remote, and an LED to indicate when it was transmitting.


    [​IMG]


    in my prototype I have the four outputs of the receiver connected to drive two leds and two different speakers. each button operated a different thing. you could do a similar design with the 4 buttons representing forward, backward, left and right.
    absf likes this.
  4. jonnyphenomenon

    jonnyphenomenon Active Member

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    for the price, 25.00 might seem steep. especially when you could just go find one of those matchbox sized rechargable RC cars and take one apart. the operation of them is quite simple. the motor goes forward and backward at one speed, and the left and right signals tell a coil to energize positive or netative, which pulls the coil towards magnets on the left or right there by steering the wheels either way.

    I applied this exact principal in a remote controller airplane project I worked on as well.

    [​IMG]

    I harvested the parts from this old RC toy and used them for my plane.

    [​IMG]


    Here it is charging on the stand. [​IMG]


    charging the planes battery from the remote control with a piece of wire extension.

    [​IMG]

    once I was finished, I founf that the plan worked perfectly well while mounted on the bench. but unfortunately, it flew almost exactly like a brick does. so in this next photo, I put the plane on stand on top of my speaker, took a photo, and then digitally deleted the stand. For full effect I had my helper Jason to form a ducking pose.

    [​IMG]


    not bad for an afternoons experimenting with RC gismos. :)

    Anyway. I hope that my posts were inspiring at least. dont be afraid to start tinkering.
    absf likes this.
  5. MITCH electronics

    MITCH electronics Active Member

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    Hahaha you have a record player, they are sooo yesterday XD
    I still have tapes though :p

    First image, did you cut your finger?
  6. jonnyphenomenon

    jonnyphenomenon Active Member

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    Yeah, I have two turntables. (and a microphone) as well as something over 400 records. I have sworn off CD's. if I really like a band or an album, I look for it on vinyl.

    as for the finger, funn you you noticed that. as I recall, in the process of cutting apart the RC car I anihilated my fingertip. in all of those project pics I am gingerly holding that finger away from the action. and in thei picture below, you can see how Ive used krazy glue to hold it together.
    [​IMG]
  7. jonnyphenomenon

    jonnyphenomenon Active Member

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    back on topic, to the original poster, if you happen to cut apart an RC car for your project, please USE CAUTION! learn from the mistakes of others because making them all yourself will be painful!
  8. jpanhalt

    jpanhalt E-book Developer

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    Another possibility to consider would be to hack one of the newer generations of remote controlled, axial twin-blade helicopters. With these toys, the RC is by infrared (pulse code) and is similar to the coding used in the link by kermit2 (above).

    I got one on clearance for $14 a couple of weeks ago. That included everything, transmitter, receiver, three motors, some useful gears, a small LiPo battery and charger. You needed 8 AA batteries for the Tx. It was only 3 channel. Sometimes with a little electronic digging, you will find the additional channels that just aren't utilized.

    The device was entirely controlled by motor speed, not position. In other words, it didn't have servos. Steering in a car could be by differential speed rather than turning the front wheels.

    How much time do you have for this project? Where are you (US, Canada, UK, etc.)? Do you have access to any electronic tools?

    John
  9. Stiven97lol

    Stiven97lol Thread Starter New Member

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    Tnx but i need to make everything out of scratch. I have 2 month to do this and i want to have steering right and left and i want it to go backwards and forwards. i already have 3 motors and i could buy parts from radio shack. I also want to make headlights and maybe make it solar and on batteries. Im still not sure how to make it go right and left, and i dont know how to make transmitter and reciever.
  10. jpanhalt

    jpanhalt E-book Developer

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    What do you mean by "make from scratch." Are you willing to go back to the Big Bang for your starting materials? :D

    No one makes anything completely from scratch. Tx and Rx modules are available. Can you use them? What about servos: are you allowed to used them? Etc. Please give some indication of what you can and cannot use.

    From what you have said, there is no way you are going to be able to design, build, and test a complete 6-channel radio controlled car in 2 months. For starters, what frequency do you plan to use?

    Is this a science fair or a show and tell? What will making an RC car show as to your ability to design and conduct a scientific experiment?

    John
  11. Stiven97lol

    Stiven97lol Thread Starter New Member

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    I can use anything I have to use btw what are servos. It's a science fair at my school. By scratch I mean don't use a premade transmitter and receiver but make it from different parts. What are tx and rx modules? And does 6 - channel means 6 different commands? I don't care what frequency I use what difference does it make? And for this science fair I will build a car and explain how each part works but it's better if I make it from scratch because it will also be evaluated by the model. Please help me as soon as you can so I can finish it in time
  12. jpanhalt

    jpanhalt E-book Developer

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    As I said before and your comment tends to support it, you simply cannot design and build a transmitter and receiver in the time you have. Tx/Rx modules are pre-made components that perform all of the functions of the basic Tx and Rx. They will be typically in a single piece of plastic looking like an IC chip, or they may be a small PCB. Generally, you will need to add modulation/demodulation functions to them. Again, you need to scale your project to your level of knowledge and time available.

    As for frequency, every country regulates what frequencies can be used for what purposes. Since you apparently don't want to say where you are, you will have to find that information out for yourself.

    You used the term "commands" , and there is a rough equivalence between commands and channels. I say "rough" because forward and back movement is usually just one channel (i.e., command = movement), but it can be two depending on how you design the radio. Right and left turning is usually one channel (command = direction) with the same caveat. Turning a light on or off is one channel. I just said 6 channels, because it was unclear what all you intended to do and how you intended to do it. Most RC cars have fewer channels.

    As for science vs. exhibit, I don't know how your fair is going to be judged. If it is just a craft exhibit, that's fine. In my days of judging science fairs, we adhered pretty closely to the requirement that an experiment had to be conducted, which included statement of hypothesis or question, experimental design, data collection, analysis, and conclusion(s). Students who presented displays or models, regardless of how elaborate they were, got participation ribbons, but no other awards. Our standards were made very clear before the fair. You need to find out what is expected in your fair and develop your project accordingly.

    John
  13. Stiven97lol

    Stiven97lol Thread Starter New Member

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    Ok so I'm in u.s. And I need is 4 channels but where can I get the Tx and Rx modules?
  14. jpanhalt

    jpanhalt E-book Developer

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    Have you tried Google?

    John
  15. jonnyphenomenon

    jonnyphenomenon Active Member

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    on the first page I posted links to a really simple to use RX/TX (transmit and receive) modules at rentron.com
    Ill repost
    http://www.rentron.com/remote_control/R8_4BIT.htm

    one could potentially use this kit to build the electronics for an RC car. using a couple motors, a power source and a couple of transistors you could make your car ambulatory with a bit of work.

    -------------------
    Jpanhalt: I must commend you on your seemingly limitless patience. :)
  16. Stiven97lol

    Stiven97lol Thread Starter New Member

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    Yes I dd and I couldnt find anything
  17. Kermit2

    Kermit2 Well-Known Member

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  18. Stiven97lol

    Stiven97lol Thread Starter New Member

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    Ok I looked at it. What does it include? Does it have any instructions? Can I add steering forward/ backward and lights? How can I make one channel go f/b and one channel go r/l and two channels for lights?
  19. Stiven97lol

    Stiven97lol Thread Starter New Member

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    Which frequency is for US?
  20. jpanhalt

    jpanhalt E-book Developer

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    Linx is another source of modules. The ones that have been mentioned so far work in a part of the radio spectrum reserved for such uses as garage doors and the like. Look up garage door TX and Rx.

    John
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