ESP8266

common pins

pin setup func Note
U0_RXD GPIO3 I/O UART Rx during flash programming  
U0_TXD GPIO1 I/O UART TX during flash programming; SPI_CS1

serial1 =

bootstrap

pin setup func
RESET pull up + cap 0.1 UF  
EN pull up  
IO0 pull up  
IO2 pull up on-module LED
GPIO15 pull down  

Modules

models SKU note
ESP-01-DAT = ESP-01S NWI1077-dat  
ESP-01-DAT = ESP-01M NWI1127-dat  
ESP-07S-DAT NWI1075-dat  
ESP-12F-DAT NWI1059-dat  
ESP-12S-DAT NWI1086-dat  

Sell - NWI1059-dat - NWI1086-dat - NWI1077-dat - NWI1127-dat - NWI1075-dat

ref