I am trying to make an obstacle avoiding robot with robotic arm. First, I am from software programming field with no experience in electronics, circuits and Arduino. Using online tutorials so far I am able to blink an led, bluetooth communication between PC and Arduino and sonar range measurement.

After doing a lot of research on internet I have made the following diagram to connect 4 servos, 2 motors, hc-05, sr-04 and L293D to Arduino using "fritzing" software. I have the sketches for running servos and motors but I am not sure the circuit is correct due to the lack of knowledge in electronics. My doubts are,

1) Is 6V supply enough for 4 servos and 2 dc to work?

2) Is the connection between L293D and 2 DC motors correct?

The final robot will look like (I hope!) a "mearm" like robot arm attached on top of an obstacle avoiding robot.

enter image description here

UPDATED: enter image description here

  • Can i get the program for this connection? Commented Aug 19, 2017 at 3:18

1 Answer 1


1) Is 6V supply enough for 4 servos and 2 dc to work?

If the motors are 6V motors then 6V is not only enough, it is what you need. What you should be asking is "Can my power source provide enough current.

2) Is the connection between L293D and 2 DC motors correct?

Not quite. You have only got half your grounds connected up. Also 3,4EN should be connected to Vcc1 not Vcc2.

1A/2A and 3A/4A are the direction/break pins (one high and one low for a direction, both low for break). The EN pins can be (if you wish) used to control the speed with PWM (if you have any spare) - if not then they should be tied to the logic supply voltage, Vcc1, not the power supply voltage, Vcc2, since that can be up to 36V and is way too high for logic inputs like EN.

  • Thank you for your valuable comments. I have updated the diagram as you said. Can you please check it is correct or not?
    – Matt
    Commented Jun 20, 2016 at 16:52
  • Not quite. You seem to have misunderstood the Vcc1/Vcc2 thing. Vcc2 still needs to be connected to your 6V rail, not the 5V one. It was ony 3,4EN that needed to be changed from connecting to Vcc2 to Vcc1.
    – Majenko
    Commented Jun 20, 2016 at 17:21

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