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ESP8266 Boards
3D

ESP-01S

esp8266_esp_01s

The Wi-Fi Rebel.

ESP-01S

The module that started the cheap Wi-Fi revolution back in 2014. Four usable GPIOs, zero comfort - pure nostalgia that still works.

Good to know

  • Even RX/TX are 3.3V only – use a level shifter next to a 5V Arduino!
  • Flash: GPIO0 to GND at power-up (a programmer adapter is recommended).
  • For normal boot GPIO0 and GPIO2 must be high, CH_PD (EN) pulled up.
  • The 2×4 header is not breadboard friendly; deep sleep wake-up needs a wire soldered to the chip (GPIO16–RST).

Pinout

ESP-01S – Pinout Tap to enlarge