RC CAR (Parallel Port Interfacing)

Published

Introduction: RC CAR (Parallel Port Interfacing)

INTRODUCTION (WARNING CODE CAN ONLY RUN WITH WINDOWS XP)
This project was about operating a remote control car by using an input device connected with a computer, for this purpose we had to connect the remote of RC Car with the computer so that when we operate the computer, remote would start its function and car will be operated. Therefore at the same time we had two grounds to play one was software development and second was hardware interfacing.

Step 1: Materials

S.no.    Name                                                               Quantity                                                    Cost (In Pakistani Rupees)

1-) DB-25 cable (parallel port cable)............. x 1.....................................................................Rs 250
2-) Gender changer (optional).........................x 1......................................................................Rs 100
3-) Bread Board..................................................x 1......................................................................Rs 140
4-) Wires..............................................................2 meter.............................................................Rs 25
5-) Transistor (Mps a06)...................................x 4.(or any general purpose transistor).....Rs 8 x 4
6-) LED's ............................................................,x 4 (two red two green)..................................Rs 4 x 4
7-) materials for soldering..........................................................................................................
8-) RC Car............................................................x1.......................................................................Rs 350 -900
9-)db25 male header/female ..........................x1.(depending upon your cable)..................RS 100

Step 2: Getting Started (Hardware Phase)

Hardware phase
                              first of all open the remote of the Rc car. You will analyze that there are four switches. when we press the button each switch is closed.. Before pressing the button turn on the remote and check the voltage across the terminals of the switch  it should give a value.. after pressing the switch hold the button and check the voltage it should show zero..

this concludes that our remote is working on short circuit technique. that is if there is a voltage across the switch and when its pressed it is short circuited.

Observe that one wire is common in all the switches its the ground of the circuit. which concludes that we need to solder five wires in the remote. one for each switch and one for ground.

it can be checked that when u short the ground wire with any of the switch wire the car performs the action of the switch who's wire is shorted if all the four functions are performed then it means u have picked the right ground. and the right switch wires.

here are the pcb design and the simulation of the circuit for interfacing (download parallel port circutary)

Step 3:

TRANSISTOR (as switch)
                                              Now when we press the button manually the two terminals of the switch join together.
but from parallel port we can only have voltage signal to activate the switch. we use the circuit transistor as a switch for it.

Working
               when the voltage at the base of the transistor is one (5V) then the emitter and the collector terminals are short.. as if we short them manually.hence our functionality is achieved.

these transistors were mounted on the breadboard one can also make a PCB or vero board

Leds are just used for protection as we ar shorting the terminals of the parallel port (approximately) because ther is a 0.7v drop accross the transistor so just to dissipate power and also for little beauty : )

Step 4: SOFTWARE PHASE

I Wrote a program on C++ works fine.
just control the car with arrow keys

Download the .zip file for the complete code (the code only runs on windows Xp and not on windows 7 as mentioned before).
i have tried it on windows 7 (64-bit Ultimate 6.1 build 7600) but did not worked fine.

here is a demonstration video link
http://www.youtube.com/watch?v=pr4aLUDTiiQ&feature=youtu.be


 



if U have any problem u can mail at
dinitrogenoxide@ymail.com

and please rate it if u like it

bread board testing (LOW QUALITY)

Share

    Recommendations

    • Microcontroller Contest

      Microcontroller Contest
    • Casting Contest

      Casting Contest
    • Make it Move Contest

      Make it Move Contest
    user

    We have a be nice policy.
    Please be positive and constructive.

    Tips

    Questions

    44 Comments

    Buddy!! Can't I use this for a RC Infrared Helicopter!! i'm slightly confused because of the remote has VRs Not switchers!! :)

    4 replies

    exacly u have the answer in ur question . from a parallel port u can only get 8 bit information so u can enable/disable 8 switches but when it comes to VRs then u need either more pins or serial port. therefore u cant do it. first i had the same project in mind but i faced the same problem.

    Regards
    Umer Javaid
    NUST
    Pakistan

    hello brother, what changes i should make in the source code provided by you to run a RC helicopter... please help

    Faisal Hayat

    UoW Wah Cantt

    I already answerd it above .

    "from a parallel port u can
    only get 8 bit information so u can enable/disable 8 switches but when
    it comes to VRs then u need either more pins or serial port. therefore u
    cant do it. first i had the same project in mind but i faced the same
    problem."

    maybe you can mail or whatsapp me;

    hayatkhanfaisal@gmail.com

    +923449793574

    My rc car remote switch terminal closes with the positive terminal of the remote not by ground.... i cannot connect positive to emmitter of the transistor.....what can i do....help me with dis... plz

    1 reply

    it might close with the positive terminal of the remote but the terminal that is joining must be a ground..
    In-fact it doesn't matter if it is on high voltage or low. because when the switch is pressed both go to same potential.
    therefore all you need to do is find out which terminal of the switch is high and which is low. just connect the low one to the emitter and high one to the collector and you are good to go.

    My rc car remote switch terminal closes with the positive terminal of the remote not by ground.... i cannot connect positive to emmitter of the transistor.....what can i do....help me with dis... plz

    i want to make front wheel moving r.c car which makes it easy to turn...

    wiil u have any idea or any source from where i cn learn abt it...??

    1 reply

    I dont get what are u trying to say .... do u mean u want to make a fore wheel drive?

    the above car is rear wheel drive and with turning functionality.

    please send me the program code to
    mohammedeissa10@yahoo.com
    e.mohammedeissa11@hotmail.com

    2 replies

    Also what u did is great job

    Thank u :)
    the code is available here in last step after videos there is "rc project.zip" (5MB) button click and download the complete source of the project :) enjoy

    Rate if u like it . Thanks

    Hello I know this might sound like a stupid question but is the transistor necessary?Why?
    Cause it might work even without it(just a thought but i'm not sure about it)
    And Do I still need to use batteries on the remote control?

    1 reply

    Normally when u press the button with your finger u connect two metal pates an when the are joined the voltage difference between them gets zero as a result a signal is emitted from the remote and the car reacts accordingly .. now the purpose of the transistor is to make a contact between those metal plates but using electric signal from parallelport (no physical force required) so to do that transistor is necessary as it i the device that gets short between emitter and collector when base is at a certain voltage ...therefore we can make those metal plates connected even though no one has pressed the button physically ...
    and yes u need the batteries in the remote as u have just pressed the button using the circuit if there is no battery then there is no use of pressing the button :) hope u have find your answer .u can ask if any further help is required ....... like,comment,rate :)

    thought no one will ever notice :D

    was modifing it .. did all the paint and led's .. then i only had these stickers so i put them too..