user28442: I am doing my engineering degree. I want to make a project connecting multiple ESP8266 with a router and control multiple relay boards. I am unable to use ESP8266 12E with Arduino. I used this connection shown in the link below, but it didn't work. So please help me with the solution. I also referred to all possible posts, but it didn't help. Please help me as soon as possible.
Connection:

post: How to connect ESP8266 12e directly to Arduino Uno (without shields)

user37194: There is also a library which can help you communicating with ESP2866 through Arduino called WiFiEsp.
It's like WiFi library for Arduino but instead for ESP8266.

user10394: I agree with Paul, you shouldn't use the Arduino, you can get break out boards at £1 for 10, but that's not what your problem is...
You are using a couple of resistors to do the level shifting taking the 5V to 3.3V.  This is a bad plan, you need a proper bidirectional level shifter, particularly at higher baud rates, i.e. above 1000.
You are supplying the top VCC rail with both 3V from the batteries and 3.3V from the Arduino, not the best plan IMO.
You are not supplying the Arduino with any power, I guess this is a drawing error but just in case it isn't I though I best mention it.
You have no level shifting on the Arduino's Rx line.  Its not technically needed, but you might require it particularly when the batteries are going flat.
You are using batteries and that's not a great plan.
Have you configured the ESPs using the AT command set, since you won't program them.
Just for the record the ESP has more memory it has a faster processor (80MHz) and you can still use the Arduino IDE.  You should be able to pick up boards to mount the ESPs so you can use them more easily for less that the price of the level shifters, but its your call.

user23280: I am the author of the linked question. Just to clarify, the image you're using has the old connection, which wasn't working for me. Please refer to the updated version of that connection, embed below:

The main changes were: the GPIO15 pin needs to be grounded, and the RESET pullup is now wired to the battery's 3.3v. Also the resistors were changed from 220ohms to 10k, but since it's a voltage divider it shouldn't make much of a difference.
Hope this helps anyone out there!

28442: <p>I am doing my engineering degree. I want to make a project connecting multiple ESP8266 with a router and control multiple relay boards. I am unable to use ESP8266 12E with Arduino. I used this connection shown in the link below, but it didn't work. So please help me with the solution. I also referred to all possible posts, but it didn't help. Please help me as soon as possible.</p>

<p>Connection:</p>

<p><img src="https://i.stack.imgur.com/9H6Wc.png" alt="">
post: <a href="https://arduino.stackexchange.com/questions/26709/how-to-connect-esp8266-12e-directly-to-arduino-uno-without-shields">How to connect ESP8266 12e directly to Arduino Uno (without shields)</a></p>
 37194: <p>There is also a library which can help you communicating with ESP2866 through Arduino called <a href="https://github.com/bportaluri/WiFiEsp" rel="nofollow noreferrer">WiFiEsp</a>.</p>

<p>It's like WiFi library for Arduino but instead for ESP8266.</p>
 10394: <p>I agree with Paul, you shouldn't use the Arduino, you can get break out boards at £1 for 10, but that's not what your problem is...</p>

<p>You are using a couple of resistors to do the level shifting taking the 5V to 3.3V.  This is a bad plan, you need a proper bidirectional level shifter, particularly at higher baud rates, i.e. above 1000.</p>

<p>You are supplying the top VCC rail with both 3V from the batteries and 3.3V from the Arduino, not the best plan IMO.</p>

<p>You are not supplying the Arduino with any power, I guess this is a drawing error but just in case it isn't I though I best mention it.</p>

<p>You have no level shifting on the Arduino's Rx line.  Its not technically needed, but you might require it particularly when the batteries are going flat.</p>

<p>You are using batteries and that's not a great plan.</p>

<p>Have you configured the ESPs using the AT command set, since you won't program them.</p>

<p>Just for the record the ESP has more memory it has a faster processor (80MHz) and you can still use the Arduino IDE.  You should be able to pick up boards to mount the ESPs so you can use them more easily for less that the price of the level shifters, but its your call.</p>
 23280: <p>I am the author of the <a href="https://arduino.stackexchange.com/questions/26709/how-to-connect-esp8266-12e-directly-to-arduino-uno-without-shields">linked question</a>. Just to clarify, the image you're using has the old connection, which wasn't working for me. <a href="https://i.stack.imgur.com/qjykI.png" rel="nofollow noreferrer">Please refer to the updated version of that connection</a>, embed below:</p>

<p><a href="https://i.stack.imgur.com/qjykI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qjykI.png" alt="Updated connection"></a></p>

<p>The main changes were: the GPIO15 pin needs to be grounded, and the RESET pullup is now wired to the battery's 3.3v. Also the resistors were changed from 220ohms to 10k, but since it's a voltage divider it shouldn't make much of a difference.</p>

<p>Hope this helps anyone out there!</p>
