RE: Can we connect two I2C(TWI) masters at same time to nrf52?

vishal — Tue, 11 Jul 2017 14:29:41 GMT

thank you so much Jorgen

RE: Can we connect two I2C(TWI) masters at same time to nrf52?

Jørgen Holmefjord — Tue, 11 Jul 2017 09:00:35 GMT

Hi,

Given that you use SDK version 12.0.0 or higher, the following twi_init should work:

/* TWI PIN numbers. */
#define SCL_PIN_1			  26
#define SDA_PIN_1			  27
#define SCL_PIN_2			  28
#define SDA_PIN_2			  29

/* TWI instance ID. */
#define TWI_INSTANCE_ID_1     0
#define TWI_INSTANCE_ID_2     1

/* TWI instance. */
static const nrf_drv_twi_t m_twi_1 = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID_1);
static const nrf_drv_twi_t m_twi_1 = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID_2);

/**
 * @brief TWI initialization.
 */
void twi_init (void)
{
    ret_code_t err_code;

    const nrf_drv_twi_config_t twi_1_config = {
       .scl                = SCL_PIN_1,
       .sda                = SDA_PIN_1,
       .frequency          = NRF_TWI_FREQ_100K,
       .interrupt_priority = APP_IRQ_PRIORITY_HIGH,
       .clear_bus_init     = false
    };
	
	const nrf_drv_twi_config_t twi_2_config = {
       .scl                = SCL_PIN_2,
       .sda                = SDA_PIN_2,
       .frequency          = NRF_TWI_FREQ_100K,
       .interrupt_priority = APP_IRQ_PRIORITY_HIGH,
       .clear_bus_init     = false
    };

    err_code = nrf_drv_twi_init(&m_twi_1, &twi_1_config, twi_handler_1, NULL);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_twi_init(&m_twi_2, &twi_2_config, twi_handler_2, NULL);
    APP_ERROR_CHECK(err_code);

    nrf_drv_twi_enable(&m_twi_1);
    nrf_drv_twi_enable(&m_twi_2);
}

Note that you need to enable two TWI interfaces in sdk_config.h:

#define TWI0_ENABLED 1
#define TWI1_ENABLED 1

Best regards,

Jørgen

RE: Can we connect two I2C(TWI) masters at same time to nrf52?

vishal — Mon, 10 Jul 2017 16:10:46 GMT

I want them(two i2c masters) to work simultaneously. As I need a higher data transfer rate

RE: Can we connect two I2C(TWI) masters at same time to nrf52?

Jørgen Holmefjord — Mon, 10 Jul 2017 07:39:18 GMT

Why do you need to connect the devices to different pin pairs? The TWI bus can interface multiple devices using addresses.