Espressif ESP8266 Series System Description page 21

ESP-LAUNCHER
Table 2-2: ESP-LAUNCHER interfaces
Interfaces Function description
SPI Flash 2, display screen, and MCU can be connected using HSPI interface
HSPI
(Figure 2-1-13).
Flash, host MCU, display screen, etc. can be connected using SDIO/SPI
SDIO/SPI
interface (Figure 2-1-19).
Currently the PWM interface has four channels, users can extend the
PWM channels as needed. PWM interface can be used to control LED lights,
buzzers, relays, electronic machines and etc (Figure 2-1-20).
The functionality of infrared remote control interface can be implemented
via software programming. NEC coding, modulation and demodulation are
IR
used by this interface. The frequency of modulated carrier signal is 38KHz
(Figure 2-1-24).
ESP8266EX is embedded with a 10-bit precision SARADC.
ADC_IN interface is used to test the power supply voltage of VDD3P3 (Pin
ADC
3 and Pin 4), as well as the input voltage of TOUT (Pin 6). It can be used in
sensors (Figure 2-1-25).
Sensors and display screens with 2.54mm and 1.27mm needles can be
I2C
connected using I2C interface (Figure 2-1-21).
UART0：U0TXD，U0RXD，MTDO（U0RTS），MTCK（U0CTS）
UART1：GPIO2（U1TXD）
Device with UART interfaces can be connected (Figure 2-1-5).
Downloading: U0TXD+U0RXD or GPIO2+U0RXD
Communicating: UART0: U0TXD, U0RXD, MTDO(U0RTS), MTCK(U0CTS)
Debugging: UART1_TXD (GPIO2) can be used to print debugging
information.
UART
By default, UART0 will output some printed information when the device is
powered on and is booting up. If this issue exerts influence on some
specific applications, users can exchange the inner pins of UART when
initializing, that is, exchange U0TXD, U0RXD with U0RTS, U0CTS. R1/3/5/7
should not be mounted with other components, while R2/4/6/8 can be
mounted with other components.
J14 and J67 should be short-circuiting connected.
Relay control terminal is used to control the switch on-and-off of smart
Relay control terminal
plugs with an indicator light (Figure 2-1-15).
Espressif 18 27 / 2016.06