https://www.electrodragon.com/product/esp-01-esp8266-wifi-module/
Pin Definitions
also printed on board
- 3.3V RX
- RST IO0
- EN IO2
- TX GND
ESP-01S
the differences between ESP-01 VS ESP-01S (more components )
ESP-01 VS ESP-01S
ESP-01S SCH
- IO15 - pull-down
- reset - pull up
- chip_EN - pull up
- GPIO0 - pull up
- GPIO2 - LED + pull up