Introduction: Send Email With ESP8266 and Arduino UNO

How to get Adafruits "send_email_smtp.ino" to send email with ESP8266 and Arduino UNO.

And eliminating the problem with "no response from module" many have.

The module works on 3.3v logic according to documentation, but I had no issue with 5v rx and tx of arduino, play it at your own risk !!

Step 1: Firmware on the ESP8266

  • To get it working, must the firmware on the ESP8266 be version: ! (old firmware!)
  • USB-connect the Arduino UNO and upload the "BareMinimum"-sketch with Arduino IDE software, so nothing disturb the flasher software. (Find the BareMinimum in "File" > "Examples" > "01.Basics" > "BareMinimum")

  • Take note of what COM-port the Arduino UNO use. (See your COM in "Tools" > "Port:")
  • Close Arduino IDE after upload and unplug power/USB.
  • Wirring the ESP8266 to the Arduino UNO as pictures above shows.

  • Connect the Arduino UNO to USB again.

  • Download flasher-software and the firmware BIN-fil here :

  • Unzip the files into a folder, and run the flasher software (esp8266_flasher.exe)

  • Click on the "BIN"-button and find the BIN-fil (v0.9.2.4 AT Firmware-ESPFIX.bin) in the folder.

  • Check whether it is the correct COM port or change it to the correct port.

  • To start the upload/flashing, Click on the "Download"-button
  • If everything is runs, will the flasher software show you the status of flashing and the blue LED on the ESP8266 will blink very fast.

  • If: Failed to connect, just try unplug USB and replug the USB again and click on the "Download"-button again !
  • In the end at 99%, it will show some error but this is ok.

  • The ESP8266 has now firmware version: !!!

Step 2: Rewiring

  • Unplug power/USB.
  • Rewirring the ESP8266 to the Arduino UNO as pictures above shows. VERY IMPORTANT !!!
  • Download the "ESP8266 library" here :

  • Open the Arduino IDE software and import the library (click "Sketch" > "Include Library" > "Add ZIP. Library..." > find the -file and click "Open")
  • USB-connect the Arduino UNO again and upload the "send_email_smtp"-sketch with Arduino IDE software ("Files" > "Examples" > "Adafruit_ESP8266-master" > "send_email_smtp")

  • Now just see this YouTube video
  • And adjust the same things as he does. :-)