esp-idf/examples/peripherals/spi_slave

SPI slave example

These two projects illustrate the SPI Slave driver. They're supposed to be flashed into two separate Espressif chips connected to eachother using the SPI pins defined in app_main.c. Once connected and flashed, they will use the spi master and spi slave driver to communicate with eachother. The example also includes a handshaking line to allow the master to only poll the slave when it is actually ready to parse a transaction.

The default GPIOs used in the example are the following:

Signal	ESP32	ESP32-S2	ESP32-C3
Handshake	GPIO2	GPIO2	GPIO3
MOSI	GPIO12	GPIO12	GPIO7
MISO	GPIO13	GPIO13	GPIO2
SCLK	GPIO15	GPIO15	GPIO6
CS	GPIO14	GPIO14	GPIO10

Please run wires between the following GPIOs between the slave and master to make the example function:

Slave	Master
Handshake	Handshake
MOSI	MOSI
MISO	MISO
SCLK	SCLK
CS	CS

Be aware that the example by default uses lines normally reserved for JTAG on ESP32. If this is an issue, either because of hardwired JTAG hardware or because of the need to do JTAG debugging, feel free to change the GPIO settings by editing defines in the top of main.c in the master/slave source code.