nRF5340: Unable to Access I2C with nRF connect SDK v.2.1.2

RE: nRF5340: Unable to Access I2C with nRF connect SDK v.2.1.2

skim — Wed, 23 Nov 2022 22:06:54 GMT

After checking the voltage, I was able to fix the issue. We can close this ticket. Thank you!

Sincerely,

SK.

RE: nRF5340: Unable to Access I2C with nRF connect SDK v.2.1.2

Vidar Berg — Wed, 16 Nov 2022 09:47:47 GMT

Hello,

The ST driver I mentioned can be used via the sensor subsystem as demonstrated by the Generic 3-Axis accelerometer polling sample and LIS2DH: Motion Sensor Monitor sample. However, please note that these are for the LIS2DH IC and not the LIS2DS IC you use so you will need to adapt the sample (change compatible and node name) to ensure the build system includes the correct driver.

From the specification I see the LIS2DS does not support supply voltages >1.98 V. Have you made sure the nRF5340 supply/IO voltage does not exceed this?

https://www.st.com/en/mems-and-sensors/lis2ds12.html

Best regards,

Vidar

RE: nRF5340: Unable to Access I2C with nRF connect SDK v.2.1.2

skim — Wed, 16 Nov 2022 01:00:07 GMT

Hello, I edited overlay files following your suggestion, but unfortunately i2c still didn'twork with SDK 2.1.2. It still worked with SDK 2.0.0. Do you have any other suggestions?

Also, I enabled lis2dh12 driver. In the overlay file, we defined its i2c reg address (reg = <0x1d>). Is there any way to use this value instead of using hardcoded value in the code (#define ST_I2C_ADDR 0x1d)?

#define ST_I2C_ADDR 0x1d // hardcoded
#define ST_REG_WAI 0x0f
uint8_t wai = 0;
ret = read_reg_value(i2c_dev, ST_I2C_ADDR, ST_REG_WAI, &wai);

1. DTS Overlay file

/  {

    // overwrite
    gpio_fwd: nrf-gpio-forwarder {
		compatible = "nordic,nrf-gpio-forwarder";
		status = "okay";
		uart {
			gpios = <&gpio1 1 0>, <&gpio1 4 0>, <&gpio0 11 0>, <&gpio0 10 0>;
		};
	};


    st_motion_interrupts {
        compatible = "gpio-keys";

        st_int1 {
            gpios = < &gpio1 0x0 (GPIO_PULL_UP | GPIO_ACTIVE_LOW) >;
            label = "st_lis2dh12_int1";
        };
    };


};

&i2c1
{
    lis2dh12@1d {
        compatible = "st,lis2ds12";
        reg = <0x1d >;
        label = "st_lis2dh12";
    };
};

// overwrite - added bias-pull-up to i2c1_sleep.
&pinctrl {
    i2c1_default: i2c1_default {
        group1 {
            psels = <NRF_PSEL(TWIM_SDA, 1, 2)>,
                <NRF_PSEL(TWIM_SCL, 1, 3)>;
                bias-pull-up; // added
        };
    };

    i2c1_sleep: i2c1_sleep {
        group1 {
            psels = <NRF_PSEL(TWIM_SDA, 1, 2)>,
                <NRF_PSEL(TWIM_SCL, 1, 3)>;
            low-power-enable;
        };
    };

};

2. Config (prj.conf) file

CONFIG_GPIO=y
CONFIG_I2C=y
CONFIG_SENSOR=y
CONFIG_LIS2DS12=y

3. Code

- unchanged

Thank you,

Sincerely,

SK.

RE: nRF5340: Unable to Access I2C with nRF connect SDK v.2.1.2

Vidar Berg — Thu, 10 Nov 2022 11:39:51 GMT

Hello,

It's strange that it worked fine with SDK v2.0.0 but not v2.1.0. I'm was not able to find any relevant changes between these 2 releases, at least.

I think the easiest way to troubleshoot this further is if you could probe the SDA/SCL lines with a scope or logic analyzer if you have that. Also, in case you use the internal GPIO pull-ups, please make sure they have been enabled with the bias-pull-up property in in your devicetree.

 &pinctrl {
	i2c2_default: i2c2_default {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
				<NRF_PSEL(TWIM_SCL, 0, 31)>;
				bias-pull-up;
		};
	};

	i2c2_sleep: i2c2_sleep {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
				<NRF_PSEL(TWIM_SCL, 0, 31)>;
			low-power-enable;
		};
	};

};

And just in case you haven't noticed, ST also include a driver for this IC in the SDK if you want to try it: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.1.2/zephyr/build/dts/api/compatibles/st,lis2ds12.html. To enable this driver you can select CONFIG_LIS2DS12=y and add the lis2dh12 subnode to your i2c:

&i2c1
{
    lis2dh12@1d {
        compatible = "st,lis2ds12";
        reg = <0x1d >;
    };
};

Best regards,

Vidar