All the functions of the WiFi Module are managed by the powerful system on chip (SoC) ESP8266, that combines a 32 bit micro-controller (and many peripherals, such as GPIO, I2C, ADC, SPI, PWM) with a WiFi radio.
RST | External reset signal, active low | MOSI * | MOSI for SPI interface | |
ADC * |
10-bit ADC Analog Input 0-1V | SCLK * | Serial Clock for SPI interface | |
CHIP-EN | Chip Enable, active high | GND | Power Ground | |
GPIO16 | General Purpose I/O | GPIO15 | General Purpose I/O | |
GPIO12 | General Purpose I/O | GPIO2 | General Purpose I/O (connected to the LED) | |
GPIO13 | General Purpose I/O | GPIO0 | General Purpose I/O | |
VCC | +3.3V power input | GPIO4 | General Purpose I/O | |
CS0 * |
Chip Select for SPI interface | GPIO5 | General Purpose I/O | |
MISO * |
MISO for SPI interface | RX | UART RX | |
GPIO9 |
General Purpose I/O (only on 12-D version) | TX | UART TX | |
GPIO10 | General Purpose I/O (only on 12-D version) |
* Not managed from miuPanel firmware.
Blue LED |
(GPIO2) | Connected to GPIO2 |
After power-up (or reset) the module can boot in two different modes, depending on the logic levels applied on pins GPIO0 and GPIO2 and GPIO15:
This module requires 3.3 V on VCC and 3.3 V for the logic. It does NOT tolerate 5 V!
If you use Arduino UNO, and you connect to the Wi-Fi module the RX and TX pins of Arduino, you will destroy the module.
Moreover, the 3.3 V source of Arduino Uno has inadequate current capability to power this module. You should use a separate 3.3 V source to power the module, with a current capability of 300 mA or higher, because the average current consumption of the Wi-Fi module is about 100 mA.
To simplify the connection of the our Wi-Fi module with a 5 V board (like Arduino), we designed the ADP-12 Breadboard adapter.