How to you read and write multiple bytes using nrf_drv_twi ?

[Robert]

How do you do i2c multiple byte read and multiple byte write using nrf_drv_twi ? Is it possible to help me with some code ? I am using s130 sdk 11.

[_Dejan_]

Maybe something like this:

static void read_data(void)
{
    nrf_drv_twi_config_t twi_config;

    twi_config.sda                = ARDUINO_SDA_PIN;
    twi_config.scl                = ARDUINO_SCL_PIN;
    twi_config.frequency          = NRF_TWI_FREQ_100K;
    twi_config.interrupt_priority = APP_IRQ_PRIORITY_HIGH;

    nrf_drv_twi_init(&twi_instance, &twi_config, NULL, NULL);
    nrf_drv_twi_enable(&twi_instance);

    //SEND COMMAND
    uint8_t command[] = {0x24, 0x25};

    nrf_drv_twi_tx(
        &twi_instance, 
        0x20, //ADDRESS
        command,
        sizeof(command),
        true
    );

    uint8_t some_data[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
    nrf_drv_twi_rx(
        &twi_instance, 
        0x20, //ADDRESS
        some_data,
        sizeof(some_data)
    );
			
    //Do something with some_data

    nrf_drv_twi_disable(&twi_instance);
}

P.S. Im newbie in microcontroller programming(working around week with them) so maybe in code are some mistakes which can produce overflow or something similar...

[_Dejan_]

If my answer fix your problem please accept it as solution/answer...

[Muhammad Akram Karimi]

Hi, I also have similar confusion about Multi byte I2C write. It seems that TWI_HANDLER is triggered once only means only 1 byte (register address) is transferred and the actual register value which is the 2nd byte is not transferred.

Your help will be appreciated. Thanks

[Jørgen Holmefjord]

If you are using the TWI master driver (nrf_drv_twi), the available events that is passed to the TWI event handler is described here. NRF_DRV_TWI_EVT_DONE event will be passed to the event handler when the entire transfer is completed, not for each byte transmitted/received. The legacy TWI (non-EasyDMA) peripheral can generate events for each byte transmitted/received (EVENTS_TXDSENT/EVENTS_RXDREADY), but this is not supported in the driver.