Trying to communicate with an ESP8266

Question

G'day guys, I'm trying to get an ESP8266 to work with an Arduino Uno.
Here is the wiring.


wiringPicture

When I go to the serial monitor (115200 baud) and type: AT, there is not response from the ESP8266.

Is there something that I am missing?

I also have a servo motor connected, it works fine.

include "Arduino.h"
include "ESP8266.h"
include "dweet.h"
include "Servo.h"
define ESP8266_PIN_RX 10
define ESP8266_PIN_TX 11
define SERVO9G_PIN_SIG 2
const int servo9gRestPosition = 20;
const int servo9gTargetPosition = 150;
const char *SSID = "Wireless Network";
const char *PASSWORD = "wireless_password";
ESP8266 wifi(ESP8266_PIN_RX,ESP8266_PIN_TX);
Servo servo9g;
const int timeout = 10000;
char menuOption = 0;
long time0;
void setup() 
{
 Serial.begin(9600);
 while (!Serial); //await connection.
 Serial.println("start");
 wifi.init(SSID, PASSWORD);
 servo9g.attach(SERVO9G_PIN_SIG);
 servo9g.write(servo9gRestPosition);
 delay(100);
 servo9g.detach();
}
void loop() 
{ 
 servo9g.attach(SERVO9G_PIN_SIG); 
 servo9g.write(servo9gTargetPosition); 
 delay(500); 
 servo9g.write(servo9gRestPosition); 
 delay(500); 
 servo9g.detach(); 
}

I'm using the ESP8266 Library.
When trying to connect it just says Initializing device...

• user31481: Arduino Uno is 5V; ESP8266 is 3.3V. I have tried that combination without level shifters and it doesn't seems to work. Currently I'm using nodeMCU with a Pro Mini, both 3.3V, communicating over I2C. You have two problems here: 1) Communication between Arduino and ESP8266; 2) Communication between ESP8266 and WiFi. Now, nodeMCU is a much capable board than Arduino if you don't need so many I/O pins. Better you discard the Arduino and keep the ESP8266.
• gre_gor: "115200baud" and Serial.begin(9600);. Something doesn't match. Also powering a motor from an Arduino is never a good idea.
• user1234433222: G'day mate, I have managed to flash the firmware with what I hope is the latest, I did the AT command and it said Ok, however when I did the command that allows you to see wireless networks, it says error. Also how do you reckon I hook the motor up? I read that the motor is 5v so i would have thought that it would be ok?
• tony gil: @user1234433222 thats another question

Answer 1

Unless you have some project constraints which make it mandatory to use naked ESP8266, why not use a NodeMCU to communicate with the Arduino in a master/slave relation over I2C?

enter image description here

#include <Wire.h> 
#define I2CAddressESPWifi 8

in setup()

Wire.begin(D1,D2); // SCL D1 SDA D2

then call from anywhere inside your loop() call this function

char readSlave(int x) { // send current time
 String xY = String(x);
 char c;
 int charArrayLength = xY.length()+1;
 char bufferChar[charArrayLength];
 Wire.beginTransmission(8);
 xY.toCharArray(bufferChar, charArrayLength);
 Wire.write(bufferChar);
 Wire.endTransmission();
 delay(10);
 Serial.print("wire sent: [");
 Serial.print(x);
 delay(50);//Wait for Slave to calculate response.
 int counter = 0;
 char buffMe[32];
 int bytesIn = Wire.requestFrom(8,32);
 while (Wire.available()) {
 delay(2);
 buffMe[counter] = Wire.read();
 /*
 c = Wire.read();
 Serial.print(c);
 */
 counter++;
 }
 delay(10);
 Wire.endTransmission(); 
 delay(500);
 Serial.print("] bytesIn: [");
 Serial.print(bytesIn);
 Serial.print("] buffMe: [");
 Serial.print(buffMe);
 Serial.print("]");
 return buffMe;
}

and your arduino will be waiting (setup)

Serial.begin(9600);
// slave listens for call from master NodeMCU
Wire.begin(I2CAddressESPWifi); // predefined as `8` or whatever address you choose
Wire.onReceive(receiveEvent);
Wire.onRequest(requestEvent);

and at the end of your code

void receiveEvent(int howMany) {
 if (howMany) {
 Serial.print("bytes[");
 Serial.print(howMany);
 Serial.print("] Received[");
 char charIn[howMany];
 int counter = 0;
 while (Wire.available()) {
 char c = Wire.read();
 charIn[counter] = c;
 //Serial.print(c);
 counter++;
 }
 delay(10);
 //do something with command from master
 }
}
void requestEvent() {
 char bufferChar[20] = "slave answer string"; // automatically null terminated extra character at end
 Serial.println(bufferChar);
 Wire.write(bufferChar);
}

• user1234433222: thank you, I will purchase one and see how I go :)