ESP-01 Wi-Fi module (ESP8266) with ESP32

Supply 3.3 V Bus GPIO
GNDGPIO2GPIO0RXDTXDCH_PDRSTVCC

Pins and ESP32 wiring

PinRoleESP32 pinNotes
GNDGroundGND
GPIO2Not wired to the ESP32—Must be HIGH at boot. Leave unconnected
GPIO0Not wired to the ESP32—LOW at boot = flash mode. Leave HIGH for normal use
RXDInput (the ESP32 drives it)D25UART: the part receives data here. Connect to an ESP32 TX pin
TXDOutput (the part drives it)D26UART: the part sends data here. Connect to an ESP32 RX pin (AT firmware: 115200 baud)
CH_PDNot wired to the ESP32—Enable: must be HIGH. Tie to 3.3 V
RSTNot wired to the ESP32—Reset, active LOW. Leave unconnected or tie HIGH
VCCPower3V33.3 V only. Draws up to about 170 mA when sending

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

Sources

Try it in 3D in BoardPilot

BoardPilot Part data (JSON)

Related parts

Part data: CC BY 4.0, free to reuse with credit to BoardPilot.