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Rf remote controlled robot

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madhurisharma

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hello,
can anyone help me...

i've recently finished my project titled "RF remote controlled robot".
actually the project is dc motor control using RF module and i've fitted wheels to the motors so it works as robot.
i'm attaching the abstract,circuit diagram

remote control transmitter part consists of 4 switches,based on which the controls are sent to the motor to rotate it in desired directions..
in my project i've pulled the TE(14 pin) of HT12E to gnd directly.....


now,my pblm is when i give the following commands at the switches the following is the result expected

0101-forward
1010-bckward
0001-left turn
0100-right turn
1001-left spin
0110-right spin
0010-left back
1000-right back

all these movements are working perfectly well....but only after some delay,

that is when i switch on the supply and press any switch the robot starts rotating in one particular direction and does not stop untill i manually stop it by switching off the power supply (even though i remove my finger by just touching the switch).....same is the case with any switch for abt 3-4 min...

after i manually stop the robot several times...(in abt 3-4 min) everything will be fine

soon after i touch a switch and leave the robot stops and the output is perfect for the above mentioned commands

i dont understand why there is this start up pblm?

can anyone pls help me?
 

Attachments

  • wireless motor control through RF.pdf
    223.5 KB · Views: 676
  • robot with receiver module on board.jpg
    robot with receiver module on board.jpg
    136.8 KB · Views: 589
  • rf transmitter module.jpg
    rf transmitter module.jpg
    121.3 KB · Views: 461
I agree with Nigel.

Also, is that 9v battery powering the motor as well as the control electronics? BAD IDEA. Use a separate supply for the motor, or a bigger battery altogether.

JimB
 
there were no capacitors on my board..as u could see in the pics and in the circuit diagram followed in the abstract..

So how do you expect it to work?, leaving out crucial components means it's guaranteed not to.

As JimB also pointed out, running off a PP3 battery is a further recipe for disaster, either use much larger batteries, or (far better) separate batteries for logic and motors (with much larger ones for the motors).

But with no supply decoupling at all, it's doomed to failure regardless.
 
@jimB

yes,that is 9V battery used to power the motors directly and i've used a 7805 regulator to power the rest of the control electronics...

can u explain me,the use of larger batteries or seperate batteries,i mean how theycan help in solving the problem
 
yes,that is 9V battery used to power the motors directly and i've used a 7805 regulator to power the rest of the control electronics...

can u explain me,the use of larger batteries or seperate batteries,i mean how theycan help in solving the problem

ADD THE REQUIRED CAPACITORS!!

Until you add the essential capacitors it's never going to work, using seperate batteries reduces interference between the motors and logic, and means it will run for a LOT longer (PP3's don't last very long).
 
I am facing same problem as @madhurisharma ...... i have made such robot and also havent used capacitors in it. Also i have used seprate 12 v supply for motors, but it blown my L293D....!!! Also one problem is there when the switch is pressed the motor stops and when the switch is released motor starts rotating. This is reverse. one solution on this tha i used INVERTER ..... but it doesnt gives correct output many times. Pls Help Me....
 
Also there is NO WAY its going to work when there is no 5V DC supply to pin 14 of the 7404 hex inverter

Dave
 
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