Add WiFi with less than $5

[Fernando Garcia]

Hi!

I'm happy to say now is possible add WIFI to your DIY controller with less than $5.

For it is needed a NodeMCU and a logic level shifter because it works with 3.3V.

I'm using a NodeMCU V3 because it has an ESP-12 and USB interface built-in and it's very cheap.

Parts:

1 x NodeMCU V3 ;
1 x Logic level shifter 5 to 3.3 V

Wiring:

See the video to learn how to set up the MQTT client.

Warning: Don't forget to turn off the UART debug log in ESP-link interface.

Watch on youtube.com

Enjoy!

PS. Any model of ESP8266 supported by ESP-link can be used but please do not ask me how to make the wiring to change the firmware.

[Fernando Garcia]

Hi!

I found a better way to add WiFi to Ferduino. This is not a $5 solution but at least no soldering is required and the build will be more clean.

This board by RobotDyn has built-in an ESP8266.

You can follow the video above, you have just to set the dip switches in right position to each situation.

To upload the firmware (ESP-link) to ESP8266:

Switches 1, 2, 3 and 4 = OFF
Switches 5, 6 and 7 = ON
Switch 8 is not used!

To see the debug messages from ESP8266 serial port:

Switches 1, 2, 3, 4 and 7= OFF
Switches 5 and 6 = ON
Switch 8 is not used!

To upload upload sketch (Ferduino or test codes) to ATmega2560:

Switches 1, 2, 5, 6 and 7= OFF
Switches 3 and 4 = ON
Switch 8 is not used!

To see debug messages from ATmega2560 serial port:

Switches 1, 2, 5, 6 and 7= OFF
Switches 3 and 4 = ON
Switch 8 is not used!

To enable communication between ATmega2560 and ESP8266 after install Ferduino (or test code) and ESP-link.

Switches 3, 4, 5, 6 and 7= OFF
Switches 1 and 2 = ON
Switch 8 is not used!

The Ferduino (and test code) is using the Serial 3 to communication between ESP8266 and ATmega2560 so you should place the smaller switch to position TXD3/RXD3.

Since Serial3 now is used for ESP8266 so Serial1 should be used for stamps.

To use this RobotDyn board you should download the branch RobotDyn_Mega_WiFi available here.

Enjoy!

P.S. I haven't RobotDyn board so if there's some error in my instructions let me know.