GPIO Allocation

The table below lists all ESP32 GPIOs used by the SLWF-09, their assigned functions, and the type of interface or peripheral they control. Pins marked with “*” are only used when the corresponding add-on module (Ethernet or Microphone) is installed. The PoE add-on does not consume any GPIO pins. 

 

 

 

 

 

 Type 

 Function 

 GPIO 

 

 

 

 

 Boot/Prog 

 Not exposed 

 GPIO0 

 

 

 LED 

 On board LED 

 GPIO2 

 

 

 LED 

 LED data output 1 (DATA) 

 GPIO4 

 

 

 LED 

 LED data output 2 (for clocked LEDs) 

 GPIO17 

 

 

 I²C 

 I²C SCL (expansion) ( 10k pull up ) 

 GPIO5 

 

 

 I²C / Mic 

 I²C SDA / Mic SCK* ( 10k pull up ) 

 GPIO14 

 

 

 Mic 

 Mic WS* 

 GPIO15 

 

 

 Mic 

 Mic SD* 

 GPIO32 

 

 

 Ethernet 

 PHY RXER* 

 GPIO13 

 

 

 Ethernet 

 PHY Clock Enable / OSCEN* 

 GPIO16 

 

 

 Ethernet 

 MDIO* 

 GPIO18 

 

 

 Ethernet 

 TXD0* 

 GPIO19 

 

 

 Ethernet 

 TXEN* 

 GPIO21 

 

 

 Ethernet 

 TXD1* 

 GPIO22 

 

 

 Ethernet 

 MDC* 

 GPIO23 

 

 

 Ethernet 

 RXD0* 

 GPIO25 

 

 

 Ethernet 

 RXD1* 

 GPIO26 

 

 

 Ethernet 

 CRS_DV* 

 GPIO27 

 

 

 Relay 

 LED power line control 

 GPIO33 

 

 

 Button 

 Button 1 

 GPIO34 

 

 

 DIY1 

 DIY input/output 

 GPIO36 

 

 

 Ethernet 

 Ethernet detect* 

 GPIO37 

 

 

 DIY2 

 DIY input/output 

 GPIO38 

 

 

 Button 

 Button 2 

 GPIO39 

 

 

 Reserved 

 Not connected (NC) 

 GPIO35