Document link https://tinyurl.com/y2svtas5, The 01S is DOUT protocol, please choose SPI MODE as DOUT when you program it
Baud Rate: 115200, Selectable working mode: On-board toggle switch. UART side for serial TTL debugging by AT commands, PROG for firmware programming
USB to serial TTL chip: CH340G, please install driver before use it
ESP-01 serial wifi module can be directly plugged into the yellow pin header without any connection wires
What you will get: 1PCS ESP-01S and 1PCS Adapter