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Wireless switch...!! — Parallax Forums

Wireless switch...!!

RITESH KAKKARRITESH KAKKAR Posts: 254
edited 2011-06-17 10:00 in General Discussion
Hi, i have to make switch for robot car, i don't know what technology should be used after lot of search, i asking help.
Please tell easy circuit.
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Comments

  • LeonLeon Posts: 7,620
    edited 2011-02-04 08:48
    What should it do?
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-04 18:09
    Leon wrote: »
    What should it do?

    It will control motor(wheel) of robot car.
  • bsnutbsnut Posts: 521
    edited 2011-02-04 18:59
    You can use s Wireless Key Fop, which has three buttons and its receiver also has three relays for each of the buttons on the transmitter. This will provide you with basic control over your robot.
  • ctwardellctwardell Posts: 1,716
    edited 2011-02-04 19:10
    Ritesh,

    So you are building a radio controlled car?

    Do you need to control steering, speed, direction (forward, reverse)?

    How big is it?

    Can you give some specs on the drive motor, current, voltage, etc.?

    C.W.
  • TtailspinTtailspin Posts: 1,326
    edited 2011-02-04 19:14
    How big is the Motor?

    Did You really build that thing in the video?
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-04 19:34
    ctwardell wrote: »
    Ritesh,

    So you are building a radio controlled car?

    Do you need to control steering, speed, direction (forward, reverse)?

    How big is it?

    Can you give some specs on the drive motor, current, voltage, etc.?

    C.W.


    i am making it first time.
    the motor is simple 100rpm gear motor, there will be four wheel which will act as steering. the voltage will be 12-10V (3A).
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 20:28
    Is the car radio controlled?

    Do you want the radio to control the switch?

    It's not too hard to have a switch on a radio control transmitter control a relay.

    Do you want to just switch power to the motor or is there a controller that also needs to be turned on and off?
  • Mike GreenMike Green Posts: 23,101
    edited 2011-02-04 22:01
    Ritesh,
    You seem to be a student. One of the tasks an engineer has to learn is how to describe what they want from a design. This is a good time to practice.

    You've said that you want to control some kind of robot car wirelessly. What you haven't provided is any kind of detail that would help others in providing advice.

    As Leon asked, what do you want to be able to control wirelessly? What functions do you want the wireless link to do? What do you already have for controllers or interface circuitry? What kind of voltages and/or current is involved? What kind of response time do you need? I know you've finally provided some of this information when pushed, but you have to provide much more and without us having to ask for every little detail. For example, you've given some information about the drive motor. What about steering? Are there other functions?
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-05 05:01
    Mike Green wrote: »
    Ritesh,
    You seem to be a student. One of the tasks an engineer has to learn is how to describe what they want from a design. This is a good time to practice.

    You've said that you want to control some kind of robot car wirelessly. What you haven't provided is any kind of detail that would help others in providing advice.

    As Leon asked, what do you want to be able to control wirelessly? What functions do you want the wireless link to do? What do you already have for controllers or interface circuitry? What kind of voltages and/or current is involved? What kind of response time do you need? I know you've finally provided some of this information when pushed, but you have to provide much more and without us having to ask for every little detail. For example, you've given some information about the drive motor. What about steering? Are there other functions?

    Hi, i want 4 switch only, rest of thing in car i can do myself like steering ( for this i will put 2 side tyres in opposite direction), for current and voltage i will use relays, etc..!!

    I want switch connectivity should be fast for controlling.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-02-05 05:48
    OK, we'll stay in conceptual mode, you can get the gear from Parallax.
    it'ssuperficial.jpg
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  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-05 07:50
    PJ Allen wrote: »
    OK, we'll stay in conceptual mode, you can get the gear from Parallax.

    Sorry i don't get you.

    please tell in deep.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-02-05 09:02
    Read about the BS2.
    Read about the XBee.
    Read about the NES Gamepad.
    Read about operating relays.
    Buy the gear.
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-05 09:19
    PJ Allen wrote: »
    Read about the BS2.
    Read about the XBee.
    Read about the NES Gamepad.
    Read about operating relays.
    Buy the gear.

    I want to make it without using micro controller.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-02-05 09:29
    Oh.
    How're you going to do that?

    A home broadcaster and switches connected to a tone generator (DTMF? 555?) for the transmitter.

    A radio with a tone detection scheme for the receiver and click some relays.
    Problem solved.

    Next!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-05 09:34
    SparkFun sells a small five button controller call "Nordic FOB" It takes care of everything from the transmit side.

    You'll still need to receive the signal and control a relay on the receiving side. If you use the above mentioned transmitter, you'll want another nRF24L01+ device for a receiver. Here is one with a chip antenna. And another with a RP-SMA connector.

    You'll need a microcontroller to interface with the wireless device. The microcontroller listens for the signal of the off button and then controls the relay connected to your power line.

    This seems like a lot just to turn something on and off. This is way we ask about other control systems with your car. If you are already using a microcontroller to control the steering of the car then it could be used to listen to the wireless device.

    What I described is very similar to what PJ Allen diagramed. I just replace the three devices on the transmit side with the Nordic FOB.

    There may be a device that controls a relay by just pressing a button or throwing a switch but I don't know of one.

    Is there a reason you want this switch separate from the rest of the car control? It seems like it would be easier to control the power with the same control system used to control the car. Is the car autonomous and you just need a way to turn it on and off?

    Edit: I wrote this without seeing the previous three posts. Good luck doing it without a microcontroller.
  • LeonLeon Posts: 7,620
    edited 2011-02-05 09:45
    I've used the nRF24L01+, it's ideal for this application. I've interfaced the Sparkfun modules to PIC18F4520 devices, which have plenty of I/O, on a couple of prototyping boards. Here are details of the hardware and some basic software:

    http://www.leonheller.com/MiRF%20V2/[/url

    One of my boards has an RS-232 port, so it can act as a host connected to a PC.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-05 10:06
    Leon,

    I personally haven't used the nRF24L01+ modules. I do have a bunch of the older nRF2401A modules. I use them in my small chem lab for data collection and logging. I also have one in a robot I control remotely with a Wii Nunchuck. I like how small they are.

    But your method breaks the rules. No microcontollers allowed. If you watch Ritesh's youtube video, you'll see he has been able to control some 7 segment displays without using a microcontroller.
  • LeonLeon Posts: 7,620
    edited 2011-02-05 10:07
    It does make things much easier if an MCU costing <$2 is added, though. The nRF24L01+ is much easier to use than the older nRF2401A, it has a genuine SPI port, for instance.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-02-05 10:14
    See, you just have to buy the gear.
  • Mike GreenMike Green Posts: 23,101
    edited 2011-02-05 10:16
    You might look at LINX Technologies. They make RF remote control devices and some of their older devices are designed to provide on/off signalling that takes the place of switch closures.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-05 10:23
    A nice little gizmo would be a board with a mRF24L01+ a MCU and five relays. I think latching relays would probably be best. Each of the five buttons on the FOB could control one relay. It would be an easy way to control stuff for those who don't want to learn about (or use) microcontrollers themselfs.

    Do you know if a mRF24L01+ can communicate with a the older nRF2401A modules? I think I have over a half a dozen older modules and I'm hesitant to purchase any mRF24L01+ modules if they can't communicate with my older ones. I know the plus version can communicate with the non plus versions but I don't know if the can communicate with the 01A versions.
  • kf4ixmkf4ixm Posts: 529
    edited 2011-02-05 10:24
    you could also use two xbees one set up with a switch on one of the input lines, other side of switch to ground, pull up's enabled on i/o's through x-ctu. then the other xbee set with same i/o pin as other xbee set to an output and that pin feeding an input on an ssr or equivalent, not to exceed the ratings of the xbee pins, to control the motor.
  • LeonLeon Posts: 7,620
    edited 2011-02-05 10:27
    Duane:

    The nRF24L01+ and nRF24L01 are upwards compatible with the nRF2401+ from a transmission protocol point of view. You won't get the best out of the system, but it would be a good way of using your older kit. I've got a couple of the older SFE modules, as well, which I've had talking to each other, a long time ago, but I haven't tried using them with the newer ones.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-05 10:32
    LINX stole my idea.

    Leon, I'm Duane not Mike. Or does Mike use these Nordic modules too?
  • LeonLeon Posts: 7,620
    edited 2011-02-05 10:39
    Sorry, I meant you. I've amended the post.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-02-05 10:44
    Maybe 567s are better available in India?
    The LM567, it's a real joy and definitely not a microcontroller.
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  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-05 20:55
    PJ Allen wrote: »
    Maybe 567s are better available in India?
    The LM567, it's a real joy and definitely not a microcontroller.

    Hi, i have seen a video in you tube using 565 ic it was working fine.
    Please tell the circuit of it.
  • Mike GreenMike Green Posts: 23,101
    edited 2011-02-05 21:18
    The LM565 is completely different.

    Do a Google search for the LM567. You'll find datasheets, application notes, sample circuits, etc. It is very easy to find this sort of information on the Internet. Do the simple research yourself. Ask for help on the difficult questions.
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-06 06:01
    The LM565 is completely different.


    Sorry, it is 567 IC, i wrote in hurry.
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-02-09 19:43
    RITESH KAKKAR wrote: »
    Sorry, it is 567 IC, i wrote in hurry.

    Hi, i want to use Holtek 121E/D ic for wireless, please tell what point to see while buying it..!!
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