ESP32 SPI slave example?

Projects Networking, Protocols, and Devices
1

I've been searching for "ESP32 Arduino SPI slave example" with no results.
I've found git libraries without examples.

I wonder if "SPI slave" has been implemented yet for ESP32?

Gammons great SPI tutorial Gammon Forum : Electronics : Microprocessors : SPI - Serial Peripheral Interface - for Arduino seems to apply to ESP8266 only.
When compiling his SPI slave sketch for ESP32 it looks like ESP32 understands nothing about:

ISR (SPI_STC_vect)
SPCR |= _BV(SPE);
#define _BV(b) (1UL << (b))
etc....

Is it possible to implement SPI slave for ESP32 with Arduino? How?

Thanks,
tipo

2

Gammons great SPI tutorial Gammon Forum : Electronics : Microprocessors : SPI - Serial Peripheral Interface - for Arduino seems to apply to ESP8266 only.

Wrong, it applies to AVR Arduinos only. All ESPs don't support SPI slave functionality in hardware to my knowledge.

Is it possible to implement SPI slave for ESP32 with Arduino? How?

It might be possible with a software emulation but probably only at lower frequencies.

3

Thanks, pylon.

How about ESP32 SPI master: can that be done with Arduino?

I need to get some bytes from ESP32 to ESP8266.
Earlier I found out that it can't be done with I2C because of ESP32 limitations.
If SPI doesn't work either, what's left to try...?

4

How about ESP32 SPI master: can that be done with Arduino?

Yes, just use the SPI library include in the corresponding Arduino core.

I need to get some bytes from ESP32 to ESP8266.

Use UART. Or WiFi.