Implementing AT commands with Arduino and ESP8266

Question

Being a newbie to Arduino, I'm trying to implement AT commands in the serial monitor, though in vain. After connecting the ESP8266 (01) module to an Arduino Uno, I tried to scan for the nearest network present [code link: https://github.com/esp8266/Arduino/blob/master/doc/esp8266wifi/scan-examples.md#simple-scan] and it worked perfectly.

But the moment I am trying to connect to send AT commands (even manually), it shows nothing. In addition, if(Serial.available()) and if(esp8266.available())< both are giving false value.

What am I doing wrong?

Answer 1

You don't give a circuit diagram or very much detail about what you've done, but if I guess correctly...

You have flashed the code in your link to the ESP-01 (perhaps using the Arduino as a serial port adapter). That code is now running on the ESP itself - it's not running on the Arduino and controlling the ESP.

Flashing the ESP erases the stock firmware, so the ESP can no longer respond to AT commands.

I don't know of a way to reprogram the 'AT' firmware into the ESP but perhaps Google will help.

If I've guessed incorrectly, please explain exactly what you have done - with circuit diagram, setup steps and code.

Answer 2

Anyone who is new to using ESP8266 module should consider following before interfacing it with Arduino

1. Try connecting ESP Module directly with your computer and test out all the AT Commands you will be implementing with Arduino. This approach is better because (a) this will give you confidence that your communication works perfectly (b) you will figure out all the problems that people face when sending AT commands and receive reply (c) this is a more visual approach so you will know what is going on and where you are going wrong.

2. Use Computer based communication tools and make a simple power adaptor to solve communication and wiring problems once and for all.