I2C fails to initialise when using with nRF52 DK

[nit1995]

The PM Sensor fails to initialise when using with nRF52 DK. I am using Segger Embedded Studio. The code keeps getting routed to NRF_BREAKPINT_COND in app_error_weak.c. This is the error I am getting.

`Error 8: Initialization of I2C connection failed!

app: PM Sensor Initialization started. app: ERROR 3735928559 [Unknown error code] at /home/dinesh/temp_data/nRF5_SDK_15.0.0_a53641a/modules/nrfx/drivers/src/nrfx_twim.c:250 PC at: 0x0002F8C3 app: End of error report` Any help would be appreciated.

[rnestler]

@nit1995 Can you post the relevant parts of the code you are using? With just such a generic error message it's hard to tell what went wrong. I guess you are using the Nordic_nRF5_series/sensirion_hw_i2c_implementation.c?

Did you verify that the pin numbers match your platform?

   /**
    * Nordic specific configuration. Change the pin numbers if you use other pins
    * than defined below.
    */
   #define SENSIRION_SDA_PIN 0
   #define SENSIRION_SCL_PIN 2

[nit1995]

Yes. I am using Nordic_nRF5_series/sensirion_hw_i2c_implementation.c and I changed the pin numbers to match the nRF52 DK board. I have included the sensirion_common.h, sensirion_arch_config.h, sensirion_common.h, sensirion_i2c.hand sps30.h. I have used the following example code:

static void test_sps30_pm_sensor(void)
{

    //struct sps30_measurement m; //make it global variable
    char serial[SPS_MAX_SERIAL_LEN];
    u8 auto_clean_days = 4;
    u32 auto_clean;
    u16 data_ready;
    s16 ret;
    nrf_delay_ms(5000);
    // Start execution.
    NRF_LOG_INFO("PM Sensor Initialization started.");
    int x = sps30_probe();
    while (x != 0) {
        printf("PM Sensor Initialization failed\n");
        NRF_LOG_INFO("PM Sensor Initialization failed.");
        // sleep(1);
    }
    printf("PM Sensor Initialization successful\n");

    ret = sps30_set_fan_auto_cleaning_interval_days(auto_clean_days);
    if (ret)
        printf("error %d setting the auto-clean interval\n", ret);

    ret = sps30_start_measurement();
    if (ret < 0)
        printf("error starting measurement\n");
    printf("measurements started\n");
    // sleep(1);
    nrf_delay_ms(1);

    //do {
    do {
        ret = sps30_read_data_ready(&data_ready);
        if (ret < 0)
            printf("error %d reading data-ready flag\n", ret);
        else if (!data_ready)
            printf("data not ready, no new measurement available\n");
        else
            break;
        //usleep(100000); /* retry in 100ms */
        nrf_delay_ms(100);

    } while (1);

    ret = sps30_read_measurement(&m);
    if (ret < 0) {
        printf("error reading measurement\n");

    } else {
        printf("measured values:\n"
                "\t%0.2f pm1.0\n"
                "\t%0.2f pm2.5\n"
                "\t%0.2f pm4.0\n"
                "\t%0.2f pm10.0\n"
                "\t%0.2f nc0.5\n"
                "\t%0.2f nc1.0\n"
                "\t%0.2f nc2.5\n"
                "\t%0.2f nc4.5\n"
                "\t%0.2f nc10.0\n"
                "\t%0.2f typical particle size\n\n",
                m.mc_1p0, m.mc_2p5, m.mc_4p0, m.mc_10p0,
                m.nc_0p5, m.nc_1p0, m.nc_2p5, m.nc_4p0, m.nc_10p0,
                m.typical_particle_size);

    }

    ret = sps30_stop_measurement();
    // sleep(1);
    nrf_delay_ms(1);
    //  } while (1);

    return 0;
}

The code keeps getting stuck at NRF_BREAKPOINT_COND.

[rnestler]

OK. So since the nrf_drv_twi_init call seems to fail (From the error message Error 8: Initialization of I2C connection failed! which gets emitted in sensirion_i2c_init), I would guess that something with the configuration or the used NRF_DRV_TWI_INSTANCE is wrong.

Can you compare the default config for the used NRF_DRV_TWI_INSTANCE with the one set in the init function? For example by just printing the .scl, .sda, .frequency and .interrupt_priority field of the default config.

Otherwise you may be better of asking in a Nordic / nRF32 support forum about the I2C/TWI interface, since the error happens in the nRF code.

[michapr]

@nit1995 : maybe it is any communication / buffer problem?

You can try my simple sketch - maybe it will help. you can here better look for the problem, maybe. https://smarthome-work.com/blog/?particulate-matter-sensor-sps30-and-arduino

It is working with small buffer too - but then only for the first 5 values.

[rnestler]

@nit1995 Could you get it to work? If yes I'll close the issue. If no is there a way we can support you?