Error When Compiling I2C Code

[Asanka]

Hello,

I wrote a sample code to read 8bits from an I2C device as below.

#include <zephyr/kernel.h>
#include <zephyr/drivers/i2c.h>

#define I2C0_NODE DT_NODELABEL(arduino_i2c)

static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C0_NODE);

int main(void)
{
        if (!device_is_ready(dev_i2c.bus)) {
	        printk("I2C bus %s is not ready!\n\r",dev_i2c.bus->name);
	        return;
        }

        while(true) {
                uint8_t data;
                int ret = i2c_read_dt(&dev_i2c, &data, sizeof(data));

                if(ret != 0){
	                printk("Failed to read from I2C device address %x.\n", dev_i2c.addr);
                }
                printk("Data %x", data);
        }

        return 0;
}

But I get the following error when I try to compile.

/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/device.h:85:41: error: '__device_dts_ord_DT_N_S_soc_S_peripheral_40000000_S_i2c_9000_BUS_ORD' undeclared here (not in a function); did you mean 'DT_N_S_soc_S_peripheral_40000000_S_i2c_9000_ORD'?
   85 | #define DEVICE_NAME_GET(dev_id) _CONCAT(__device_, dev_id)
      |                                         ^~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_internal.h:72:26: note: in definition of macro '__DEBRACKET'
   72 | #define __DEBRACKET(...) __VA_ARGS__
      |                          ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_internal.h:64:9: note: in expansion of macro '__GET_ARG2_DEBRACKET'
   64 |         __GET_ARG2_DEBRACKET(one_or_two_args _if_code, _else_code)
      |         ^~~~~~~~~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_internal.h:59:9: note: in expansion of macro '__COND_CODE'
   59 |         __COND_CODE(_XXXX##_flag, _if_1_code, _else_code)
      |         ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_macro.h:180:9: note: in expansion of macro 'Z_COND_CODE_1'
  180 |         Z_COND_CODE_1(_flag, _if_1_code, _else_code)
      |         ^~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/drivers/i2c.h:120:17: note: in expansion of macro 'COND_CODE_1'
  120 |                 COND_CODE_1(DT_ON_BUS(node_id, i3c),                    \
      |                 ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/toolchain/common.h:133:23: note: in expansion of macro '_DO_CONCAT'
  133 | #define _CONCAT(x, y) _DO_CONCAT(x, y)
      |                       ^~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/device.h:85:33: note: in expansion of macro '_CONCAT'
   85 | #define DEVICE_NAME_GET(dev_id) _CONCAT(__device_, dev_id)
      |                                 ^~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/device.h:211:37: note: in expansion of macro 'DEVICE_NAME_GET'
  211 | #define DEVICE_DT_NAME_GET(node_id) DEVICE_NAME_GET(Z_DEVICE_DT_DEV_ID(node_id))
      |                                     ^~~~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/device.h:228:34: note: in expansion of macro 'DEVICE_DT_NAME_GET'
  228 | #define DEVICE_DT_GET(node_id) (&DEVICE_DT_NAME_GET(node_id))
      |                                  ^~~~~~~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/drivers/i2c.h:105:16: note: in expansion of macro 'DEVICE_DT_GET'
  105 |         .bus = DEVICE_DT_GET(DT_BUS(node_id)),                          \
      |                ^~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/drivers/i2c.h:122:30: note: in expansion of macro 'I2C_DT_SPEC_GET_ON_I2C'
  122 |                             (I2C_DT_SPEC_GET_ON_I2C(node_id)))          \
      |                              ^~~~~~~~~~~~~~~~~~~~~~
../src/main.c:6:43: note: in expansion of macro 'I2C_DT_SPEC_GET'
    6 | static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C0_NODE);
      |                                           ^~~~~~~~~~~~~~~
zephyr/include/generated/devicetree_generated.h:7924:75: warning: unsigned conversion from 'int' to 'short unsigned int' changes value from '1073778688' to '36864' [-Woverflow]
 7924 | #define DT_N_S_soc_S_peripheral_40000000_S_i2c_9000_REG_IDX_0_VAL_ADDRESS 1073778688 /* 0x40009000 */
      |                                                                           ^~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_internal.h:72:26: note: in definition of macro '__DEBRACKET'
   72 | #define __DEBRACKET(...) __VA_ARGS__
      |                          ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_internal.h:64:9: note: in expansion of macro '__GET_ARG2_DEBRACKET'
   64 |         __GET_ARG2_DEBRACKET(one_or_two_args _if_code, _else_code)
      |         ^~~~~~~~~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_internal.h:59:9: note: in expansion of macro '__COND_CODE'
   59 |         __COND_CODE(_XXXX##_flag, _if_1_code, _else_code)
      |         ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/sys/util_macro.h:180:9: note: in expansion of macro 'Z_COND_CODE_1'
  180 |         Z_COND_CODE_1(_flag, _if_1_code, _else_code)
      |         ^~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/drivers/i2c.h:120:17: note: in expansion of macro 'COND_CODE_1'
  120 |                 COND_CODE_1(DT_ON_BUS(node_id, i3c),                    \
      |                 ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/devicetree.h:4233:33: note: in expansion of macro 'DT_N_S_soc_S_peripheral_40000000_S_i2c_9000_REG_IDX_0_VAL_ADDRESS'
 4233 | #define DT_CAT4(a1, a2, a3, a4) a1 ## a2 ## a3 ## a4
      |                                 ^~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/devicetree.h:2201:9: note: in expansion of macro 'DT_CAT4'
 2201 |         DT_CAT4(node_id, _REG_IDX_, idx, _VAL_ADDRESS)
      |         ^~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/devicetree.h:2224:30: note: in expansion of macro 'DT_REG_ADDR_BY_IDX'
 2224 | #define DT_REG_ADDR(node_id) DT_REG_ADDR_BY_IDX(node_id, 0)
      |                              ^~~~~~~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/drivers/i2c.h:106:17: note: in expansion of macro 'DT_REG_ADDR'
  106 |         .addr = DT_REG_ADDR(node_id)
      |                 ^~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/drivers/i2c.h:122:30: note: in expansion of macro 'I2C_DT_SPEC_GET_ON_I2C'
  122 |                             (I2C_DT_SPEC_GET_ON_I2C(node_id)))          \
      |                              ^~~~~~~~~~~~~~~~~~~~~~
../src/main.c:6:43: note: in expansion of macro 'I2C_DT_SPEC_GET'
    6 | static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C0_NODE);
      |                                           ^~~~~~~~~~~~~~~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/devicetree.h:4229:24: note: in expansion of macro 'DT_N_NODELABEL_arduino_i2c'
 4229 | #define DT_CAT(a1, a2) a1 ## a2
      |                        ^~
/home/asanka/ncs/v2.5.0/zephyr/include/zephyr/devicetree.h:197:29: note: in expansion of macro 'DT_CAT'
  197 | #define DT_NODELABEL(label) DT_CAT(DT_N_NODELABEL_, label)
      |                             ^~~~~~
../src/main.c:4:19: note: in expansion of macro 'DT_NODELABEL'
    4 | #define I2C0_NODE DT_NODELABEL(arduino_i2c)
      |                   ^~~~~~~~~~~~
../src/main.c:6:59: note: in expansion of macro 'I2C0_NODE'
    6 | static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C0_NODE);
      |                                                           ^~~~~~~~~
../src/main.c: In function 'main':
../src/main.c:12:17: warning: 'return' with no value, in function returning non-void [-Wreturn-type]
   12 |                 return;
      |                 ^~~~~~
../src/main.c:8:5: note: declared here
    8 | int main(void)
      |     ^~~~

I'm quite new to this platform and I appreciate any help with this. Thank you.

[ovrebekk]

Hi 

If you are new to Nordic I would strongly check out the Nordic Developer Academy. The introductory course even includes a chapter dedicated to I2C which should help you get started. 

I expect the problem with your sample is that you haven't created an I2C sensor in your overlay. The I2C_DT_SPEC_GET() macro will not work on the I2C top node itself, you have to use it with one of the sensors (or buses) on the I2C interface. The devacademy chapter will explain this in more detail. 

Best regards
Torbjørn

[Asanka]

Hello,

Thank you so much. I went through the exercise and implemented I2C and it worked! At least I don't get any errors for now. However, to complete the communication, the other device must receive the chip select pin as LOW. I went ahead and tried to use the GPIO 0.00 to use as a chip select. But the code doesn't continue after:

gpio_is_ready_dt(&cs)

I am working on the Make It Matter project and I'm trying to complete my firmware. This is why I didn't yet complete this course as there's only a limited number of days left.

My code is as follows:

#include <zephyr/kernel.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/gpio.h>

#define I2C0_NODE DT_NODELABEL(mysensor)
#define CS0_NODE DT_NODELABEL(cs0)

static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C0_NODE);
static const struct gpio_dt_spec cs =
	GPIO_DT_SPEC_GET_OR(DT_NODELABEL(cs0), gpios, {0});


int main(void)
{
        if (!device_is_ready(dev_i2c.bus)) {
	        printk("I2C bus %s is not ready!\n\r",dev_i2c.bus->name);
	        return;
        }

	if (!gpio_is_ready_dt(&cs)) {
		printf("The CS GPIO port is not ready.\n\r");
		return 0;
	}

        gpio_pin_configure_dt(&cs, GPIO_OUTPUT);

        while(true) {
                uint8_t data;
                int ret = i2c_read_dt(&dev_i2c, &data, sizeof(data));

                gpio_pin_set_dt(&cs, 0);

                if(ret != 0){
	                printk("Failed to read from I2C device address %x.\n\r", dev_i2c.addr);
                } else {
                        printk("Data %x", data);
                }

                gpio_pin_set_dt(&cs, 1);
        }

        return 0;
}

The overlay file is below:

&i2c1 {
    compatible = "nordic,nrf-twim";
    status = "okay";

    mysensor: mysensor@4a{
        compatible = "i2c-device";
        reg = < 0x4a >;
        label = "MYSENSOR";
    };
};

&gpio0 {
    compatible = "nordic,nrf-gpio";
    status = "okay";

    cs0 {
        gpio-hog;
        gpios = <0 GPIO_ACTIVE_LOW>;
        output-high;
    };
};

Any suggestion is highly appreciated.

[ovrebekk]

Hi Asanka

Why would an I2C sensor have a chip select line? 

Chip select is used by SPI devices, I haven't seen any I2C devices use it. 

Regardless I don't think your overlay is quite correct. 

I did something similar in a hobby project of mine, where I needed two output pins that could be manually controlled. 

You can see the overlay here, and the relevant source here and here.

Best regards
Torbjørn 

[Asanka]

Thank you. This is the device that I'm trying to control. It's an ADC.

I will take a look at the overlays. I appreciate the support.

[ovrebekk]

Hi 

That looks like an SPI device to me, not an I2C device. If this is the case the I2C interface will struggle to communicate with it, since it will not receive any acknowledge. 

Best regards
Torbjørn