Olimex ESP32 GATEWAY board - thilo-hub/Lua-RTOS-ESP32 GitHub Wiki

Ethernet (RMII interface):

Signal	GPIO
EMAC_TXD0	GPIO19
EMAC_TXD1	GPIO22
EMAC_TX_EN	GPIO21
EMAC_RXD0	GPIO25
EMAC_RXD1	GPIO26
EMAC_RX_CRS_DV	GPIO27
CLKIN	GPIO 0
MDC	GPIO23
MDIO	GPIO18

PHY is LAN8720 at address 0. Power GPIO is not used.

SD Card (MMC interface):

Signal	GPIO
CD/DAT3/CS	GPIO13
CMD/DI	GPIO15
CLK/SCLK	GPIO14
DAT0/DO	GPIO2
DAT1/RES	GPIO4
DAT2/RES	GPIO12

UART:

Unit	Signal	GPIO	Notes
0	RX	GPIO3
	TX	GPIO1
1	RX
	TX
2	RX
	TX

SPI:

Unit	Signal	GPIO	Notes
2	MISO
	MOSI
	CLK
	CS
3	MISO
	MOSI
	CLK
	CS

I2C:

Unit	Signal	GPIO	Notes
0	SDA
	SCL
1	SDA
	SCL