Connect Arduino to ESP8266 WiFi module

In this tutorial we will show how to connect ESP8266 WiFi module to Arduino. We will use software serial port. HW serrial port will be available for program uploading and debugging. 

ESP8266 WiFi module is WiFi serial transceiver module, based on ESP8266. Small size and low cost makes it suitable for sensor nodes. It works on 3.3V and consumes current up to 250mA. Current consumption is quite big so it’s usually not powered on battery

For arduino board we will use Arduino pro mini 3.3V 8Mhz and software serial port. HW serrial port will be available for program uploading and debugging. Later you can switch module to HW serial port.

Before we start using ESP8266 WiFi module we need to update ESP8266 firmware. We use V0.9.2.2 version of firmware. Detail instructions how to update firmware can be found here. New firmware default baudrate is 9600 which makes possible to use software serial on Arduino board.

ESP8266 current consumption is too big to use Arduino internal regulator. We will use dedicated power regulator AMS1117. Make sure to use big enough additional capacitors to prevent voltage drops when transmitting.

Power supply

Connecting  ESP8266 WiFi module and Arduino Pro Mini 8Mhz, 3.3V

ESP8266 WiFi module pinout

 

ESP8266 module	Arduino pro mini module	Power supply
VCC	VCC	3.3V VCC power supply
GND	GND	GND power suppy
RST	3
UTXD	10
URXD	11
CH_PHD		3.3V VCC power supply