Connect with us

Simple circuit for running and reversing a motor....

Discussion in 'Sensors and Actuators' started by eptheta, Jan 23, 2010.

  1. saurabh17g

    saurabh17g

    72
    0
    Mar 8, 2010
  2. eptheta

    eptheta

    188
    0
    Dec 20, 2009
    Whoa! Come on, there has to be an easy way. Think of it this way:
    forget the motor completely, and think only of my parallel port. I have an LED on a breadboard somewhere far away and i have my parallel port output.
    I could just connect the +ve terminal of the LED to the parport and the negative to ground for it to light up, but instead, i want to send this signal wirelessly.
    I wanted a device which will allow me to simply transmit a signal, which would trigger a similar but amplified signal somewhere else.

    A very simple implementation of the above stated device is an LED and a phototransistor.
    Say i connect my LED to my parallel port and at a distance say 10 cm away and power it. This is intercepted by my phototransistor which triggers another LED to glow.. This is ultimately what i want, only the distance has to be about 5 meters or even less.

    Another way of implementing this (only in theory for me) is using a radio signal generator. My parallel port will provide the signal to start producing radio waves at a particular frequency. A pick-up device on the breadboard with the LED will be tuned to intercept that frequency of radio waves produced and amplify it, only to produce another signal to switch on the LED and not necessarily power it. Thus a decent distance can be achieved.

    I think the main confusion here is about using the parport signals to power the device, which i do not want to do. Instead, i just want to provide a signal bit ( just like the base of an NPN transistor) which can be amplified (or used to trigger) another power source located relatively far away.

    I am content with using a parallel port and i don't see how it could be a hindrance to the project.

    I hope i made my intentions clear, and no offense to anyone here, and i do appreciate all the help you all are giving, but i think since (*steve*) and Resqueline have been following my progress from the beginning, i would appreciate it if they could help me out here too.

    Thanks a lot.
     
  3. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    You are right. It is really that easy. I can not make it any easier than what you have already figured out.

    Good luck.

    ---55p
     
  4. eptheta

    eptheta

    188
    0
    Dec 20, 2009
    Oh...darn.. Well thanks for your help in any case. Once again, i appeal to steve and Resqueline for help. Please ?
     
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    Perhaps you can start by telling us what you actually want to achieve -- the end result.
     
  6. saurabh17g

    saurabh17g

    72
    0
    Mar 8, 2010
    first thing- using LED and photo transistor.. not quite correct.
    Line of sight problem.+ distance problem

    Instead i would suggest u to use TSOP trans-rec pair. But that too will have the same limitation but not to that extent.

    second thing- radio frequency generator is not that different than FSK that I told you in my earlier post. Thats the possible way. I suggested u to go for USB to serial driver as I was assuming that u will use laptop to drive your motors. And laptop does not have serial port.

    these 2 sentences-
    I think the main confusion here is about using the parport signals to power the device, which i do not want to do. Instead, i just want to provide a signal bit ( just like the base of an NPN transistor) which can be amplified (or used to trigger) another power source located relatively far away.

    I am content with using a parallel port and i don't see how it could be a hindrance to the project.


    --- appear to contradict each other
    Does laptop have a parallel port? My laptop does not have it. Instead it has a single port which has dimensions of serial port but has 18 pins.

    What do u want to do exactly?
     
  7. eptheta

    eptheta

    188
    0
    Dec 20, 2009
    I've posted this earlier. I think it is rather clear. Let's say broadly i want to make a remote controlled car. So i'm starting small (with the motor) and will build upwards.

    Hope you can help.
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    OK, if it's a remote controlled car then you've now got a circuit that can reverse the motor.

    The next thing is some way of getting the signal to the car. There are a number of options, infra-red, RF, ultrasonic, etc. You need to decide which is best/easiest for you.

    Once you've decided that you need to determine how best to encode and decode commands on that signal so as to get information transmitted from the controller to the car.

    Then you need to determine how these commands will be translated into actions (e.g. setting motor direction).

    You might like to consider small 433MHz transceiver modules (like these for example).

    Your next task is to figure out a way of sending data across the link. A comparatively easy way is to use a PICAXE. Google "picaxe 433" for a list of links describing how to do this.

    Then is the easy part of interfacing one picaxe to a couple of buttons and the other to the motor.

    Once you have the basics right you are just a little software away from making it do more fancy stuff.
     
  9. saurabh17g

    saurabh17g

    72
    0
    Mar 8, 2010
    I read the datasheet of DR3100 and my understanding is that it is ASK trans-receiver.
    Still there is a better way. Use Max 7032 FSK tx.rx . FSK is more robust to noise and interference. I do not know the availibilty, cost and bandwidth of MAX 7032. Also , after reading the datasheet http://datasheets.maxim-ic.com/en/ds/MAX7032.pdf, i found that it requires NRZ or Manchester encoding which you have to implement at the output of your PC.
    PC->parallel port->coding circuit(level of PC converted to NRZ or manchester)->MAX7032 PCB(as tx)
    At receiver-> MAX7032 PCB(as rx)->decoding circuit(level NRZ or manchester to analog voltage levels to control motor)-> motor circuit.

    @Steve:
    Your next task is to figure out a way of sending data across the link. A comparatively easy way is to use a PICAXE. Google "picaxe 433" for a list of links describing how to do this.

    Then is the easy part of interfacing one picaxe to a couple of buttons and the other to the motor.

    why the PICAXE is needed? that ASK ic is transmitter /receiver.
    so it will send data across the link
     
    Last edited: Mar 12, 2010
  10. eptheta

    eptheta

    188
    0
    Dec 20, 2009
    Finally we're on the right track ! Thanks for returning steve !
    @saurabh17g, I'm a complete beginner when it comes to analog circuitry, so i'm not sure what to expect from the modules you mentioned. However, i will still try and buy them if they are available. Oh also, thanks a lot for your help around here.

    At the end of the day, i'm looking for the easiest way of transmitting data. I'm not into anything too fancy, and i don't 'need' too much range of operation... So i'm open to the most convenient option(which i'm hoping you can suggest).
    I looked up the 433Mhz modules and they seem promising. I hope i can get my hands onto a few. It will take a bit of figuring out, but i think i may be able to manage. However i want to keep my options open.

    I'll post back here when i've gone through the documents and datasheets and if i have a problem, i'll ask.
    If you have any more help to offer i'd be grateful.
    Thanks again...
     
  11. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    Firstly, it allows the transmitter to be an independent device (if that is what is required)

    Secondly it allows some smarts at the receiver end to translate future commands into more complex behaviour (say, setting motor speed)

    Thirdly it decouples the PC from any timing sensitive stuff. It allows relatively simple coding on the PC (i.e setting states -- go forward) without requiring critical timing that may not be simple in a multitasking environment.

    Fourthly, many people have done it before and there is *lots* of helpful information on the web.

    four point fifthly, it's reasonably cheap.

    Fifthly, I am reasonably conversant with this technique and will be able to assist.

    Sixthly, thanks for the pointer to the other options -- I'll look them up :)

    edit:

    Seventhly, the 433MHz transmitters are available as built up modules, the chip you suggested will require all the support circuitry and RF sections to be built.

    The comment that a LED and a phototransistor is not suitable is probably a little off the mark. Whilst this simplistic approach certainly is, there are a variety of modules (used for TV remote controls) that are effectively just this -- they modulate a 30-50 KHz carrier and the receiver is sensitive to a narrow (and corresponding) frequency. It's a viable option. Possibly cheaper, and although it has less range, possibly sufficient. Check out this page for more info.
     
    Last edited: Mar 13, 2010
  12. saurabh17g

    saurabh17g

    72
    0
    Mar 8, 2010
    @Steve
    thanks for the info.I was useful and informative.
    i understood the advantages of PICAXE.

    But my suggestion or quote was, there is either/or between ASK and PICAXE. It is not like having a same circuit with both the modules present, right?

    i read the project at http://jap.hu/electronic/codec.html

    i liked it and was quite informative.
    But some basic questions->
    in Tx section, the what is-> Tx module ANT IC?

    second question: for IR led, is it like according to the number of key pressed, it changes the 'on' / 'off' pattern or how is the other way to distinguish the signal at the receiver end.
     
  13. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    Maybe. I'm not familiar with the solution you offered. I did note that it required an RF stage which would be rather tricky for a beginner to handle. In contrast the PICAXE and transceiver module requires nothing very fancy in terms of layout and could almost certainly be breadboarded.

    I guess if you're willing to walk through a design using that chip, eptheta will be in a position of having more options. It's not a path that I can walk however (I have no experience with that chipset)

    Looks like some basic transmitter module. The corresponding receiver seems to have power supply connections and a logic level output.

    Yes, in the simplest case each button causes a different code to be sent. It varies depending on how information is encoded, but a simplistic analogy would be to different characters being sent by RS232.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-