esp-idf/examples/peripherals/spi_slave
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receiver
sender
README.md

README.md

SPI slave example

These two projects illustrate the SPI Slave driver. They're supposed to be flashed into two separate ESP32s 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.

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

Signal Slave Master
Handshake GPIO2 GPIO2
MOSI GPIO12 GPIO12
MISO GPIO13 GPIO13
SCLK GPIO15 GPIO15
CS GPIO14 GPIO14

Be aware that the example by default uses lines normally reserved for JTAG. 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.