After hours of try&error I found a good solution:

Set up the FSPI and GDMA by using the regular C functions:

ESP_ERROR_CHECK(spi_bus_initialize(SPI2_HOST, &buscfg, SPI_DMA_CH_AUTO));
ESP_ERROR_CHECK(spi_bus_add_device(SPI2_HOST, &devcfg, &spi));

Do a fake transmission to init all registers ...

Did you remember to de-reset and un-clockgate the peripheral first? If it's off, it won't do anything.


Found a hint in ok-home 's link:

REG_CLR_BIT(SYSTEM_PERIP_CLK_EN0_REG, SYSTEM_SPI2_CLK_EN);
REG_SET_BIT(SYSTEM_PERIP_CLK_EN0_REG, SYSTEM_SPI2_CLK_EN);
REG_SET_BIT(SYSTEM_PERIP_RST_EN0_REG ...

Hello
maybe this will help you
https://github.com/ok-home/logic_analyzer/tree/master

include/logic_analyzer_hal.h
Gets samples into ESP32 buffer
logic_analyzer_config_t - capture configuration
start_logic_analyzer(logic_analyzer_config_t *config) - capture start
void (*logic_analyzer_cb_t)(uint8 ...

Did you remember to de-reset and un-clockgate the peripheral first? If it's off, it won't do anything.

Thanks for the answer.

For the clockgate I did

REG_WRITE(SPI_CLK_GATE_REG(2), 7);


After you sayed "de-reset" i searched for a way to do this, found only this:

SPI_SOFT_RESET Software ...

Hi,

I am new to the ESP32, but my first project already pushes this controller to its limits.

The goal is to capture a very uncommon video signal on the FSPI port, and re-transmit it as a VGA-signal.
The input signal have 3 wires: a combined SYNC signal and 2 Bit color (well, 4 shades of green ...