user63110: DC motor: 3-6v 
Servo sg90: 3-7.2v
Esp 8266 01: 3.3v

I have 2 Arduino Uno both has their own ac-dc power adapter. 
Lets say, 1st Arduino is Ard1 and 2nd is Ard2.
The Ard1 communicates to a web server (BLYNK) with Esp 01.
Using I2C, Ard1 sends command to Ard2 to power/move the DC motor/Servo.
So far, it has no problem operating with Servo. But,
Whenever the Ard1 commands the Ard2 to power the DC motor. 
Right when the DC motor runs(using digitalWrite(motor,HIGH)) the Esp 01 resets.


Tried using analogWrite(motor, 102) though it won't reset instantly, prolong usage randomly resets it anytime.
I also tried to test operating Servo and DC motor simultaneously in Ard2 using Serial commands, without I2C/Esp01. There was no problem at all, both works flawlessly.

Below is the diagram of the wiring.


user35097: Can you clear one thing that you are giving power to dc motor from 5v pin given on Arduino board or from your ac to dc power supply. If you are giving power to the motor from 5v pin of Arduino Uno then there is a high possibility that the motor is not getting sufficient current because 5v supply on Arduino comes from onboard lm1117 5v voltage regulator and cheap clon Arduino has a cheap regulator with less than 1amp capacity.

63110: <pre><code>DC motor: 3-6v 
Servo sg90: 3-7.2v
Esp 8266 01: 3.3v
</code></pre>

<p>I have 2 Arduino Uno both has their own ac-dc power adapter. 
Lets say, 1st Arduino is <code>Ard1</code> and 2nd is <code>Ard2</code>.</p>

<p>The <code>Ard1</code> communicates to a web server (BLYNK) with Esp 01.</p>

<p>Using I2C, <code>Ard1</code> sends command to <code>Ard2</code> to power/move the DC motor/Servo.</p>

<p>So far, <strong>it has no problem operating with Servo</strong>. But,</p>

<p>Whenever the <code>Ard1</code> commands the <code>Ard2</code> to power the DC motor. </p>

<p>Right when the DC motor runs(using <code>digitalWrite(motor,HIGH)</code>) the Esp 01 resets.</p>

<hr>

<ul>
<li><p>Tried using <code>analogWrite(motor, 102)</code> though it won't reset instantly, prolong usage randomly resets it anytime.</p></li>
<li><p>I also tried to test operating Servo and DC motor simultaneously in <code>Ard2</code> using Serial commands, without I2C/Esp01. There was no problem at all, both works flawlessly.</p></li>
</ul>

<p>Below is the diagram of the wiring.
<a href="https://i.stack.imgur.com/h4a8c.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/h4a8c.png" alt="enter image description here"></a></p>
 35097: <p>Can you clear one thing that you are giving power to dc motor from 5v pin given on Arduino board or from your ac to dc power supply. If you are giving power to the motor from 5v pin of Arduino Uno then there is a high possibility that the motor is not getting sufficient current because 5v supply on Arduino comes from onboard lm1117 5v voltage regulator and cheap clon Arduino has a cheap regulator with less than 1amp capacity.</p>
