Build Instructions

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• 1

  Part list

  For this project, i used the cheapest and smallest components I could find. The ESP8266 is a great tool for any microcontroleur/wifi application today. Plus, it's now Arduino compatible!
  

  
  

  As i was adding program inside the ESP8266 100 times a day, I decided to also build a user-friendly programmer. You actually don't really need it if you don't want to change a lot of thing on the code.
  

  Device Part List :

  • ESP8266 7$ uC, Wifi and Wifi antenna.
  • Button 0.5$ choose the one fit the best in your model, I used a "pushbutton 12*12*8cm".
  • LED 0.35$Resistor 0.02$ (I used a flat top 3mm bought on Ebay)
  • Battery 6.95$ In a bigger device you could use a CR2032 to multiply the autonomy by 2.3 or even this bigger Battery to multiply by 9 !
  • SMTP2GO Account FREE. It forward the mail between the device and your mail account (the Free version is limited to 20 mails a day).
  • Email Adress FREE. I used a GMAIL one with this code.

  To program your device, you gonna need a few wires and :

  • FTDI basic board and a 3.3V power supply (min 500 mA)

  or

  • Arduino board like UNO

  On the "programming your board" part of this instructions, I posted a schematic of a more reliable programmer. You need to add the following components if you want to build it :

  • 3.3V regulator
  • Male Header (angle or straight)
  • Female Header
  • Capacitor 10uF and few resistors
  • Proto board
  • Battery connector
• 2

  Programming your board

  There are many ways to program your ESP8266 board :

  The most important component for programming is a Serial to USB converter like the FTDI FT232RL. You can find one in a special device like a FTDI board but you also have one in every Arduino Board that you can program over USB (On the UNO the FTDI has been replaced by a 32u2, but it worked exactly the same).

  If you have a UNO board for exemple, if you remove the microcontroleur you can use the RX, TX, GND, 3.3V Pin to reprogram the ESP8266. Of course, the Arduino board has to have a removable chip...

  The second important note is you have to change the GPIO 0 Pin to be able to program (Ground state) and use (3.3V state). It's sometime a bit confusing because after programing the new device code will start automatically even if GPIO 0 is still grounded. But if you restart the program you have to make sure that GPIO 0 is 3.3V or it will not work!

  So with few wire, an Arduino UNO you can program your ESP. But this technique can easily give you headache if you are programming the board a lot, because when it's not working or when you need to add other components you never know if the problem is hardware or software... So you spend a lot of time checking if no wire got unplugged or plugged in the wrong place! That's why I have built a prototype board.

• 3

  Software

  The first thing to do is to install the Arduino IDE for the ESP8266. You have all the information you need here

  Now we have the programer for the board, we have to take a look at the software. The device need to connect to the WIFI network and send a Email throw SMTP. As GMAIL (and many other Mail serveur) doesn't accept SMTP protocol, i used a SMTP2GO server as a mediator. So the device send a mail to SMTP2GO and then it is forwarded to your Email account. To open an account on SMTP2GO, it's free and take only few minutes.

  As this project is using Internet connection over Wifi and need to send Email, we have to change few lines of code for every applications. In this case it's gonna be all the places with some ******** on the code :

  - Your SSID of the internet box, the name of your wifi network

  - Your password of the internet box (WPA2/PSK in mine), so the device can connect

  - Your network setting, you have to add a fixed IP address on your internet box corresponding to the MAC address of the board. You can also program your board and read with the Arduino IDE on Serial and see when the device connect. The IP address will appear. (The problem is, it can sometime change, depending on the internet box). I think those line are actually not really useful :s

  - Your Email Address, to receive Email from the device. I used a GMAIL account and it worked fine, you have to check that your mail address is compatible with SMTP2GO.

  - The mail address and the password of the smtp2go account in base 64. You have to translate it from this website for exemple

  - You can also change the object and contents of the Email.

  Once you have done this, you can compile your file and send it to the ESP8266. Now, every time the ENABLE PIN is getting LOW and then HIGH the device will restart, turn the LED ON, connect to your Wifi, send a mail, turn the LED OFF and go to a sleep mode. The process can take between 10 and 30 seconds depending on how fast it connect.

  The only difference between the device code and the programer board is in the second one, it send a mail only when you press the button.

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