nrf91 how to use twi(i2c)?

RE: nrf91 how to use twi(i2c)?

Sigurd Hellesvik — Wed, 27 Apr 2022 12:02:31 GMT

The overlay file will not be added just because you have it in the same folder.

See Set devicetree overlays for how to set it.

Regards,
Sigurd Hellesvik

RE: nrf91 how to use twi(i2c)?

john.liu — Wed, 27 Apr 2022 04:01:33 GMT

Hi Sigurd Hellesvik:

This is the project I built, and it seems that I2C is not working after running.

https://github.com/JohnLiu-cloud/nrf91_i2c

RE: nrf91 how to use twi(i2c)?

john.liu — Wed, 27 Apr 2022 02:26:28 GMT

thank you.

I tried the following.

Either i2c0 or i2c1 is enabled but i2c2 is enabled.Am I still wrong somewhere?

RE: nrf91 how to use twi(i2c)?

Sigurd Hellesvik — Tue, 26 Apr 2022 11:29:02 GMT

See zephyr/scripts/kconfig/kconfigfunctions.py#L124-L136.

You enable it by setting the "okay" as from my last post.

status = "okay";

Regards,
Sigurd Hellesvik

RE: nrf91 how to use twi(i2c)?

john.liu — Tue, 26 Apr 2022 10:03:08 GMT

Thank you very much!!! I now understand how it works.I have one more question.

config SLM_TWI
	bool "Access TWI interface with SLM AT command"
	select I2C
	default y if "$(dt_nodelabel_enabled,i2c0)" || \
		     "$(dt_nodelabel_enabled,i2c1)" || \
		     "$(dt_nodelabel_enabled,i2c2)" || \
		     "$(dt_nodelabel_enabled,i2c3)"

How to enable "dt_nodelabel_enabled,i2c0 ".I didn't find a reference.

RE: nrf91 how to use twi(i2c)?

Sigurd Hellesvik — Tue, 26 Apr 2022 09:15:25 GMT

You can set the pins for i2c0 and/or i2c1 by using Devicetree overlays.
Here is an example for an overlay file setting the pins for one of the i2c devices:

&i2c1 {
    status = "okay";
    sda-pin = < 12 >;
    scl-pin = < 13 >;
};

Regards,
Sigurd Hellesvik

RE: nrf91 how to use twi(i2c)?

john.liu — Mon, 25 Apr 2022 15:03:56 GMT

It seems that the i2c of this is not used. Is there any other examples I can refer to.(Examples that seem easier to understand.)

RE: nrf91 how to use twi(i2c)?

john.liu — Mon, 25 Apr 2022 14:54:28 GMT

thank you.I wank to know i2c0,i2c1...which pin is used and why can't it be found.

RE: nrf91 how to use twi(i2c)?

Sigurd Hellesvik — Mon, 25 Apr 2022 11:13:41 GMT

You can add them yourself, using the syntax seen in zephyr.dts for i2c2:

            i2c2: arduino_i2c: i2c@a000 {
                compatible = "nordic,nrf-twim";
                #address-cells = < 0x1 >;
                #size-cells = < 0x0 >;
                reg = < 0xa000 0x1000 >;
                clock-frequency = < 0x186a0 >;
                interrupts = < 0xa 0x1 >;
                status = "disabled";
                label = "I2C_2";
                sda-pin = < 0x1e >;
                scl-pin = < 0x1f >;

Regards,
Sigurd Hellesvik

RE: nrf91 how to use twi(i2c)?

john.liu — Mon, 25 Apr 2022 03:07:45 GMT

Reference zephyr.dts

i2c0: i2c@8000 {

compatible = "nordic,nrf-twim";

#address-cells = < 0x1 >;

#size-cells = < 0x0 >;

reg = < 0x8000 0x1000 >;

clock-frequency = < 0x186a0 >;

interrupts = < 0x8 0x1 >;

status = "disabled";

label = "I2C_0";

};

But no define SCK and SDA pin.