On ST25DV after writing to FTM buffer cannot write to EEPROM via I2C with NRF52832.

[NKern]

app_twi_perform() returns 0x03 == NRF_ERROR_INTERNAL.

Reset board with button does not help.

After Power Cycle can update EEPROM successfully.

Accessing FTM buffer with proprietary smartphone app.

NRF52832 built with nRF SDK 12.3.

[Edvin]

Hello,

So you need to power cycle the DK (which also power cycles the EEPROM, I guess?) in order for it to work?

What happens if you try to initialize the EEPROM twice without power cycling it in between?

If you look at the unmodified twi_master_using_app_twi_pca10040 example from SDK12.3.0, you should see:

static void twi_config(void)
{
    uint32_t err_code;

    nrf_drv_twi_config_t const config = {
       .scl                = ARDUINO_SCL_PIN,
       .sda                = ARDUINO_SDA_PIN,
       .frequency          = NRF_TWI_FREQ_100K,
       .interrupt_priority = APP_IRQ_PRIORITY_LOWEST,
       .clear_bus_init     = false
    };

    APP_TWI_INIT(&m_app_twi, &config, MAX_PENDING_TRANSACTIONS, err_code);
    APP_ERROR_CHECK(err_code);
}

Can you try to change .clear_bus_init = false to .clear_bus_init = true?

See if that helps, and let me know if it doesn't.

Best regards,

Edvin

[NKern]

Hello Edvin,

unfortunately that solution did not work.

The best answer came from ST forum:

https://community.st.com/s/question/0D73W000001MsCn/

Problem was that "it is not possible to write into EEPROM if FTM is activated".

And logical solution was to deactivate FTM before interacting with EEPROM.

Anyway, I appreciate your involvement as a good sign of a great customer support.