I2C communication with two NRF DK

RE: I2C communication with two NRF DK

D.MASSIALA — Mon, 17 Mar 2025 13:59:55 GMT

i used the example given in the github link that you give and it's working :

https://github.com/nrfconnect/sdk-nrf/tree/v2.9.1/tests/benchmarks/i2c_endless

thank you for your help

RE: I2C communication with two NRF DK

Priyanka — Mon, 17 Mar 2025 10:12:46 GMT

[quote user=""]But i don't know my NRF52840 DK I2C adress, is there a way to make this communication possible ? [/quote]

There is no particular address and you can select any address which is not being used by any other peripheral/register.

Also,

could you try to set the compatible = "nordic,nrf-twim"; for the slave?

I would suggest you to define them according to this: https://github.com/nrfconnect/sdk-nrf/blob/v2.9.1/tests/benchmarks/i2c_endless/boards/nrf52840dk_nrf52840.overlay#L61

-Priyanka

RE: I2C communication with two NRF DK

D.MASSIALA — Fri, 14 Mar 2025 08:18:14 GMT

To resume my code :

I try to put my NRF5340 DK as a Slave using the adress 0x77 and my NRF52840 as Master.

And after i try to read my NRF5340 Adress to be sure connection is ok but it doesn't work :

*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
Failed to read from I2C device address

RE: I2C communication with two NRF DK

D.MASSIALA — Fri, 14 Mar 2025 08:10:46 GMT

For the master config i have this :

prj.conf :

#
# Copyright (c) 2016 Intel Corporation
#
# SPDX-License-Identifier: Apache-2.0
#

# STEP 2 - Enable the I2C driver
CONFIG_I2C=y
# STEP 4.2 - Enable floating point format specifiers
CONFIG_CBPRINTF_FP_SUPPORT=y

my overlay:

// To get started, press Ctrl+Space to bring up the completion menu and view the available nodes.
// For more help, browse the DeviceTree documentation at https://docs.zephyrproject.org/latest/guides/dts/index.html

&i2c0 {
    status = "okay";
    pinctrl-0 = <&i2c0_default>;
	pinctrl-1 = <&i2c0_sleep>;
    pinctrl-names = "default", "sleep";
    mysensor: mysensor@77{
        compatible = "i2c-device";
        status = "okay";
        reg = < 0x77 >;
    };
};

&pinctrl {
	/omit-if-no-ref/ i2c0_default: i2c0_default {
		group1  {
			psels = <NRF_PSEL(TWIM_SCL, 1, 14)>,
					<NRF_PSEL(TWIM_SDA, 1, 15)>;
		};
	};

	/omit-if-no-ref/ i2c0_sleep: i2c0_sleep {
		group1  {
			psels = <NRF_PSEL(TWIM_SCL, 1, 14)>,
					<NRF_PSEL(TWIM_SDA, 1, 15)>;
			low-power-enable;
		};
	};
};

my main.c

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
/* STEP 3 - Include the header file of the I2C API */
#include <zephyr/drivers/i2c.h>
/* STEP 4.1 - Include the header file of printk() */
#include <zephyr/sys/printk.h>
/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS 1000

/* STEP 6 - Get the node identifier of the sensor */
#define I2C_NODE DT_NODELABEL(mysensor)





int main(void)
{
	static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C_NODE);

	if (!device_is_ready(dev_i2c.bus)) {
		printk("I2C bus %s is not ready!\n", dev_i2c.bus->name);
		return -1;
	}

	

	uint8_t data;
	int ret = i2c_read_dt(&dev_i2c, &data, sizeof(data));
	if(ret != 0){
		printk("Failed to read from I2C device address");
	}


}

RE: I2C communication with two NRF DK

D.MASSIALA — Fri, 14 Mar 2025 08:07:54 GMT

There is some details of my code for the Slave configuration :

my prj.conf :

#
# Copyright (c) 2016 Intel Corporation
#
# SPDX-License-Identifier: Apache-2.0
#

# STEP 2 - Enable the I2C driver
CONFIG_I2C=y
# STEP 4.2 - Enable floating point format specifiers
CONFIG_CBPRINTF_FP_SUPPORT=y

CONFIG_I2C_NRFX=y
CONFIG_NRFX_TWIS0=y

--------------------------

my overlay :

// To get started, press Ctrl+Space to bring up the completion menu and view the available nodes.
// For more help, browse the DeviceTree documentation at https://docs.zephyrproject.org/latest/guides/dts/index.html

&i2c1 {
    status = "okay";
    pinctrl-0 = <&i2c1_default>;
	pinctrl-1 = <&i2c1_sleep>;
    pinctrl-names = "default", "sleep";
    mysensor: mysensor@77{
        compatible = "i2c-device";
        status = "okay";
        reg = < 0x77 >;
    };
};

&pinctrl {
	/omit-if-no-ref/ i2c1_default: i2c1_default {
		group1  {
			psels = <NRF_PSEL(TWIM_SCL, 1, 14)>,
					<NRF_PSEL(TWIM_SDA, 1, 15)>;
		};
	};

	/omit-if-no-ref/ i2c1_sleep: i2c1_sleep {
		group1  {
			psels = <NRF_PSEL(TWIM_SCL, 1, 14)>,
					<NRF_PSEL(TWIM_SDA, 1, 15)>;
			low-power-enable;
		};
	};
};

-------------------------

my main.c

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
/* STEP 3 - Include the header file of the I2C API */
#include <zephyr/drivers/i2c.h>
/* STEP 4.1 - Include the header file of printk() */
#include <zephyr/sys/printk.h>
/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS 1000

/* STEP 8 - Define the addresses of relevant registers */


/* STEP 6 - Get the node identifier of the sensor */
#define I2C_NODE DT_NODELABEL(mysensor)


int main(void)
{

	/* STEP 7 - Retrieve the API-specific device structure and make sure that the device is
	 * ready to use  */
	static const struct i2c_dt_spec dev_i2c = I2C_DT_SPEC_GET(I2C_NODE);

	if (!device_is_ready(dev_i2c.bus)) {
		printk("I2C bus %s is not ready!\n", dev_i2c.bus->name);
		return -1;
	}

	return 0;
}

RE: I2C communication with two NRF DK

D.MASSIALA — Fri, 14 Mar 2025 07:59:32 GMT

After some research i found this post which say that i can put my NRF52840 as a slave adding this line on prj.conf

CONFIG_I2C_NRFX=y

CONFIG_NRFX_TWIS0=y

Configuring 52832 for I2C slave mode using zephyr and VS code

i try but it doesn't work