I have two ESP32-S3s connected to each other and I'm trying to send data from one to the other. I have verified with the oscilloscope that the master side is sending the data correctly on all four data lines and SCK/CS. After that I configured the slave like this: typedef struct SPI_settings_s{ spi_...

I was hoping for 40Mhz, so yes, 16MHz is a bare minimum.

It's ok, found it, gpio_set_drive_capability. It helped a bit.

How can I do that?

OK, I've shortened the length of wires by half and now it looks better. Still far from perfect, but I guess it will be fine when all components are on one PCB.
If anybody have any suggestions on still improving the signal, it would be much appreciated.

I've created dual SPI @16MHz, connected it's output to the controller itself, pins declared as inputs. I've connected SCK and MOSI to oscilloscope and the signal looks awful. I haven't tried to receive SPI message yet, but it's hardly going to work if it looks that bad. The connection wires are with...

Finally got it. What I needed to define was flags in spi_device_interface_config_t used in spi_bus_add_device(SPI_settings.host, &SPI_settings.devcfg, &SPI_settings.spi) .devcfg = { .command_bits = 0, .address_bits = 0, .mode = 0, //SPI mode 0 .clock_speed_hz = SPI_MASTER_FREQ_40M .spics_io_num = 10...

It seems dual is not working at all? I tried different flags, like .flags = SPICOMMON_BUSFLAG_MASTER | SPICOMMON_BUSFLAG_GPIO_PINS | SPICOMMON_BUSFLAG_SCLK | SPICOMMON_BUSFLAG_DUAL | SPI_DEVICE_HALFDUPLEX Ever time the error is the same: E (183) spi_master: check_trans_valid(704): Incompatible when ...

I get error 258, which is invalid argument. Tried SPI_TRANS_MODE_QIO as well, the same error. When it's commented out, no error and output is present. I have two different ESP32S3 boards, the same problem on both.
Any suggestion?

OK, I've increased task cache (I got stack cannary watchpoint triggered) and no more error, but ... nothing is being transfered. No oscilloscope signal, even on SCK. I'll check if there is an error code when starting SPI transfer.