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Pin Definitions

GPIO assignments are configured in WolfEngine/Settings/WE_Settings.hpp under Settings.hardware.

Display (SPI)

Settings.hardware.display.cs  = 17
Settings.hardware.display.rst = 4
Settings.hardware.display.dc  = 16

These are screen control pins. CS, RST, and DC are required — without them the display won't initialize. Keep in mind that different screens use different pins but mostly SPI communication holds.

SPI Bus

Settings.hardware.spi.mosi = 23
Settings.hardware.spi.miso = 19
Settings.hardware.spi.sclk = 18

Standard SPI bus pins shared by the display.

I2C Bus

Settings.hardware.i2c.sda = 21
Settings.hardware.i2c.scl = 22

Used by I2C devices such as the PCF8574 expander. These are the ESP32 default I2C pins and work well in most cases.

Input Pins

Button GPIO assignments have their own file — see Input Settings.

Suggestions

  • Pins 21 and 22 are the ESP32 hardware I2C pins — stick with these unless you have a reason to remap.
  • Avoid GPIO 6–11 — these are connected to the internal flash on most ESP32 modules and will cause crashes if used.
  • Avoid GPIO 34–39 for SPI and I2C — they are input-only and cannot be driven as outputs.
  • If you change SPI pins, make sure they are not already claimed by another peripheral.