ESP8266 WiFi Module...

  

The picture above shows the basic circuit for programming a ESP8266 module using a 115200 baud Serial UART. I have added a simple circuit to allow the use of a single button to put the ESP8266 into upload mode. A separate button is used to soft reset the module. The LED is connected to the GPIO2 pin which can still be used for IO use but it is also used by the ESP8266 to indicate that it is in upload mode (LED lit).

The picture above shows my first prototype breadboard for ESP8266 programming. Please ignore the row of transistors on the left. The ESP8266 can be seen on the right with the control buttons in the middle. The UART is at the rear.

 

IT IS VITAL THAT A GOOD POWER SUPPLY IS PROVIDED CAPABLE OF SUPPLYING IN EXCESS OF 200mA.

THE ESP8266 IS A 3.3 VOLT DEVICE AND ITS INPUTS ARE NOT 5 VOLT TOLERANT!

Here are a couple of test sketches, one for the ESP8266 and one for an Arduino UNO or similar.

Arduino_PING_Client_for_Ethernet & UDP_PONG_Client