ESP8266 is a 3V WiFi module popular for its Internet of Things applications. It is a low-cost Wi-Fi microchip, with built-in TCP/IP networking software, and microcontroller capability, produced by Espressif Systems in Shanghai, China.
ESP8266 has 8 pins, namely:
- GPIO 0
- GPIO 2
- and GND
VCC and GND are powering pins. RX and TX are used to communicate. Refer the datasheet for more details
Powering ESP 8266
ESP 8266 maximum working Voltage is 3.6V and its very important to note.
There are many ways to power ESP8266 WiFi module: you can use 2 AA sized batteries for powering, PC port if you have a TTL-Serial-to-USB adapter (Don’t try to connect the module to a PC serial port directly, you could cause damage to the module or to your computer!). You can use LIPO batteries to power the ESP Dev Thing board. You can use LM117 3.3V voltage regulator.
The ESP8266’s maximum voltage is 3.6V, so the thing has an onboard 3.3V regulator to deliver a safe, consistent voltage to the IC. That means the ESP8266’s I/O pins also run at 3.3V, you’ll need to Logic Level Controller any 5V signals running into the IC.
Alternatively, if you have an external, regulated supply you’d like to deliver directly to the ESP8266, you can supply that voltage through the 3V3 pin (on the I2C header). While this voltage doesn’t have to be 3.3V, it must be within the range of 1.7-3.6V.