ESP32 Forum

Hi,

I am using an external flash for my project. Flash (ST-25P80) has 8Mb memory. Connections are as follows:

Pin no 30/Gpio no 18 -> CLK
Pin no 31/Gpio no 19 -> MISO
Pin no 37/Gpio no 23 -> MOSI
Pin no 27/Gpio no 16 -> CS

These pins are connected to VSPI.

This is the first time I am using SPI communication.I have tried writing the code to init SPI and start a simple communication. Below is the step-wise procedure I followed:

#define PIN_NUM_MISO 19 //31
#define PIN_NUM_MOSI 23 //37
#define PIN_NUM_CLK 18 //30
#define PIN_NUM_CS 16 //27
esp_err_t retn;
void spi_init() {
spi_device_handle_t spi;
spi_bus_config_t buscfg = {
.miso_io_num=PIN_NUM_MISO,
.mosi_io_num=PIN_NUM_MOSI,
.sclk_io_num=PIN_NUM_CLK,
.quadwp_io_num=-1,
.quadhd_io_num=-1,
.max_transfer_sz=0,
};
retn=spi_bus_initialize(VSPI_HOST, &buscfg, 1);
ESP_ERROR_CHECK(retn);
}
void flash_init(){
spi_device_handle_t spi;
spi_device_interface_config_t devcfg={
.clock_speed_hz=50*1000*1000,
.mode=0,
.spics_io_num=PIN_NUM_CS,
.queue_size=7,
};
retn=spi_bus_add_device(VSPI_HOST, &devcfg, &spi);
ESP_ERROR_CHECK(retn);
}

void app_main()
{
uint8_t wrbuff[8] = "ABCDEFGH";
uint8_t rdbuff[8] = {0};
spi_init();
spi_flash_init();
flash_init();
//spi_flash_erase_sector(0x10);
spi_flash_write(0x10000, (uint32_t*)wrbuff, sizeof(wrbuff));
spi_flash_read(0x10000, (uint32_t*)rdbuff, sizeof(rdbuff));
printf("SPI Read = %s\n", (uint8_t*)rdbuff);
}

Please help me to correct the code as it is not working.

Thanks
R.

You are using the SPI Flash API for write/read, which is unrelated to the SPI Master API you have used to initialize the SPI bus.
You should write your own driver (or use an existing) to access the ST-25P80, which, BTW, is not a Flash chip, but SPI EEPROM.

So, you mean I need to write driver for 25P80 ???

Yes, it should not be too difficult to adapt an existing SPI eeprom driver or write your own based on datasheet...

Hi,

Please send any link to refer.

Thanks