I2C1 port not responding

[Timothy]

I have a nRF9160DK board running tagoio_http_post. I am trying to use the I2C1 port. I have attached the overlay file I use to set I2C1 to P0.30 and P0.31. I have also attached prj.conf file.

I have a simple I2C test setup that I have added below. The result when I run the program is an error (-5) as shown below. can you tell me what I am doing wrong and how I get the I2C1 command to work? I am sure it is something simple I am missing. I appreciate any help you can give.

******************************

#if 1

/* start I2C test */

#include <zephyr/drivers/i2c.h>

#if DT_NODE_HAS_STATUS(DT_ALIAS(i2c1), okay)

#define I2C_DEV_NODE    DT_ALIAS(i2c1)

/#else

#error "Please set the correct I2C device"

#endif

const struct device *const i2c_dev = DEVICE_DT_GET(I2C_DEV_NODE);

uint32_t i2c_cfg = I2C_SPEED_SET(I2C_SPEED_STANDARD) | I2C_MODE_CONTROLLER;

//uint32_t i2c_cfg = I2C_SPEED_SET(I2C_SPEED_FAST) | I2C_MODE_CONTROLLER;

/* end I2C test */

#endif

#if 1

/* start I2C test */

    printf("*** I2C Init ***\r\n");

    if (!device_is_ready(i2c_dev))

    {

        myPrintfE("I2C device is not ready\r\n");

    }

    else

        myPrintfS("I2C device is ready\r\n");

    /* 1. Verify i2c_configure() */

    if (i2c_configure(i2c_dev, i2c_cfg))

    {

        myPrintfE("I2C config failed\n");

    }

    else

        myPrintfS("I2C config passed\n");

#if 1

    unsigned char datas[6];

    while(1)

    {

        /* 4. verify i2c_read() */

        datas[0] = 0xFC;

        i2c_write(i2c_dev, datas, 1, 0x40);

        int ret = i2c_read(i2c_dev, datas, 2, 0x40);

        printf("I2C 0x%02X 0x%02X %d\r\n",datas[0],datas[1],ret);

        k_sleep(K_MSEC(1000));

    }

#endif

/* end I2C test */

#endif

************************ results when run ********************

*** I2C Init ***
I2CI2C device is ready
I2C config passed
I2C 0xFC 0x00 -5
[00:00:00.754,333] <err> i2c_nrfx_twim: Error on I2C line occurred for message 0
[00:00:01.254,516] <err> i2c_nrfx_twim: Error on I2C line occurred for message 0

0743.prj.conf2818.data_logger_agriculture.overlay

[Vidar Berg]

Hello,

Do you have external pull-ups on the bus lines? If not, please enable internall pull-ups on SDA and SCL by adding the 'bias-pull-up' do your pinctrl node:

&pinctrl {
	i2c1_default: i2c1_default {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
			<NRF_PSEL(TWIM_SCL, 0, 31)>;
			bias-pull-up;
		};
	};

	i2c1_sleep: i2c1_sleep {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
			<NRF_PSEL(TWIM_SCL, 0, 31)>;
			low-power-enable;
		};
	};
};

[00:00:00.754,333] <err> i2c_nrfx_twim: Error on I2C line occurred for message 0

This error indicates that you received an address nack. 

Best regards,

Vidar

Edit: It is also necessary to enable the IO_EXP_EN through the nRF52840 board controller (nRF9160 DK board control): https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/boards/arm/nrf9160dk_nrf52840/doc/index.html#board-controller-firmware 

[Timothy]

Vidar

thanks for getting back to me so quickly. yes that was the problem. I did not have the pull_ups enabled for the nRF9160 DK board. The production board will have external pull-ups. This can be closed.