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Send AT commands to ESP8266 from Arduino Uno via a SoftwareSerial port

GOAL

From Arduino UNO, send AT commands to ESP8266 via a SoftwareSerial port and receive results.

CURRENT STATUS

I either send AT commands and get nothing back (wiring scheme 1) or I send AT commands and get garbage back (wiring scheme 2).

Using the Arduino as a pass through (as explained in the tutorial listed in the resources section), I can send AT commands. I have found that I can communicate with the ESP8266 at 115200 baud.

This is the results of running AT+GMR:

AT version:0.40.0.0(Aug 8 2015 14:45:58)
SDK version:1.3.0
Ai-Thinker Technology Co.,Ltd.
Build:1.3.0.2 Sep 11 2015 11:48:04

WIRING SCHEME 1

!! I have the green wire attached to pin 3 on the Arduino Uno and the yellow wire attached to pin 2; not 1 and 0 as the picture suggests !!

enter image description here

WIRING SCHEME 2

Same wiring as above, but I have RX and TX reversed. The green wire is attached to pin 2 and the yellow wire is attached to pin 3.

CODE

This is running on Arduino Uno

#include <SoftwareSerial.h>
SoftwareSerial esp8266(2, 3);
void setup() {
 // Open serial communications and wait for port to open:
 Serial.begin(115200);
 while (!Serial) {
 ; // wait for serial port to connect. Needed for native USB port only
 }
 Serial.println("Started");
 // set the data rate for the SoftwareSerial port
 esp8266.begin(115200);
 esp8266.write("AT\r\n");
}
void loop() {
 if (esp8266.available()) {
 Serial.write(esp8266.read());
 }
 if (Serial.available()) {
 esp8266.write(Serial.read());
 }
}

RESULTS FROM RUNNING SKETCH

Wiring Scheme 1

Started

Wiring Scheme 2

Started
�����

I have tested the ESP8266 via the instructions listed in the tutorial in the Resources I've Used section below. The ESP8266 works just fine when sending it instructions via the Serial Prompt.

RESOURCES I'VE USED http://rancidbacon.com/files/kiwicon8/ESP8266_WiFi_Module_Quick_Start_Guide_v_1.0.4.pdf

QUESTION

Does anyone know if what I am trying to do is possible? And if it is, what am I doing wrong?

Answer*

**Does anyone know if what I am trying to do is possible?**
It is possible, i've done it with 2 arduinos where one was simulating ESP8266 (waiting for ebay order).

**And if it is, what am I doing wrong?**

What you are doing is wrong on most levels, but i think you got most sorted out.

An idea is to implement this little fella: [Logic level shifter][1] it will save you many troubles later. 

On your "WIRING SCHEME 1" you are using the arduino's Hardware serial port to talk directly to the device as if it was connected through a TTL cable or FTDI cable.

This means that the arduino device would in theory read from the hardware when talking too the ESP8266, if you have another arduino or a TTL cable, try and connect it to gate 2 and 3 on the "main" arduino and you should get a similar result as for your example result 2. Since you would that way proxy through the arduino. If not that would be a place to start debugging. 

Beside that i could only recommend you in investing in either a TTL 3,3v or a logic level converter. When i got my cable everything worked out of the box. 


 [1]: http://www.banggood.com/3_3V-5V-TTL-Bi-directional-Logic-Level-Converter-For-Arduino-p-949438.html

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