How to connect other sensor to nrf9160 (i2c and GPIO)

[Liza]

Hi, 

I want to connect LDC2114 to nRF9160. I write the nrf9160dk_nrf9160_ns.overlay and the astri,ldc2114.yaml. I don't know how to set GPIOs in &i2c1 - ldc2114: ldc2114@2a which are the output pins of LDC2114 and input pins of nRF9160.

Fullscreen 1462.nrf9160dk_nrf9160_ns.overlay.txt Download

/ {
	/* Map the devices to the aliases of the application. */ 
	aliases {	
		ldc-sensor = &ldc2114;
	};
	
};

&i2c1 {
    compatible = "nordic,nrf-twim";
    #address-cells = < 0x1 >;
    #size-cells = < 0x0 >;
    reg = < 0x9000 0x1000 >;
    // clock-frequency = < 0x186a0 >;
    clock-frequency = <I2C_BITRATE_STANDARD>;
    interrupts = < 0x9 0x1 >;
    status = "okay";
    pinctrl-0 = < &i2c1_default >;
    pinctrl-1 = < &i2c1_sleep >;
    pinctrl-names = "default", "sleep";
    ldc2114: ldc2114@2a{
        compatible = "astri,ldc2114";   //binding
        status = "okay";
        reg = < 0x2a >;
        label = "LDC2114";
        gpio-controller;
        #gpio-cells = < 0x2 >;
        intb-gpios = < &gpio0 25 0 >; // LDC2114 INTB pin -> nrf9160 INPUT P0.25
        in0-gpios = < &gpio0 24 0 >;  // LDC2114 OUT0 pin -> nrf9160 INPUT P0.24
        in1-gpios = < &gpio0 23 0 >;  // LDC2114 OUT1 pin -> nrf9160 INPUT P0.23
        in2-gpios = < &gpio0 22 0 >;  // LDC2114 OUT2 pin -> nrf9160 INPUT P0.22
        in3-gpios = < &gpio0 21 0 >;  // LDC2114 OUT3 pin -> nrf9160 INPUT P0.21
    };
};

&i2c2 { 
	status = "disabled";
};

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

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

Fullscreen 2308.astri,ldc2114.yaml.txt Download

# Copyright (c) 2018, Peter Bigot Consulting, LLC
# SPDX-License-Identifier: Apache-2.0

description: Sensor LDC2114

compatible: "astri,ldc2114"

include: [sensor-device.yaml, i2c-device.yaml, gpio-controller.yaml, base.yaml]

properties:
  reg:
    required: true

  #alert-gpios:

  "#gpio-cells":
    const: 2

  intb-gpios:
    type: phandle-array
    description: |
      LDC2114 INTB pin -> nrf9160 INPUT P0.25

  in0-gpios:
    type: phandle-array
    description: |
      LDC2114 OUT0 pin -> nrf9160 INPUT P0.24

  in1-gpios:
    type: phandle-array
    description: |
      LDC2114 OUT1 pin -> nrf9160 INPUT P0.23

  in2-gpios:
    type: phandle-array
    description: |
      LDC2114 OUT2 pin -> nrf9160 INPUT P0.22

  in3-gpios:
    type: phandle-array
    description: |
      LDC2114 OUT3 pin -> nrf9160 INPUT P0.21

gpio-cells:
  - pin
  - flags

Also, What else should I do in order to connect the devices?

Best regards,

Liza

[Vidar Berg]

Hi Liza,

It looks like you have configured everything correctly in your Devicetree overlay. Are you getting build errors, or does it fail when you try to run the application?

Best regards,

Vidar

[Liza]

Hi Vidar Berg,

I cannot call gpios from ldc2114 Devicetree. Since the gpios are input pins, so I call them from node gpio0 "dev_gpio = device_get_binding(DEVICE_DT_NAME(DT_NODELABEL(gpio0)));" and it works.

Do you know how to call gpios from node ldc2114?

Best regards,

Liza

[Vidar Berg]

Hi Liza,

You can do something like this for getting the pin configuration for the driver:

static const struct gpio_dt_spec int_1_pin = GPIO_DT_SPEC_GET(ldc2114, in1_gpios);

Are you creating a custom zephyr driver? I could not find this driver in my SDK tree.

Best regards,

Vidar

[Liza]

Hi Vidar,

I write " static const struct gpio_dt_spec int_1_pin = GPIO_DT_SPEC_GET(DT_NODELABEL(ldc2114), in1_gpios); " but error occurs: Unrecognizable mark. So I said I cannot call gpios.

Vidar Berg said:

Are you creating a custom zephyr driver?

What is the "custom zephyr driver"? I am writing the ldc2114.c to init the sensor. 

Best regards,

Liza

[Liza]

This is my whole project, I haven't done the .c files. Do you think I need to add something to connect the LDC2114? It seems that I need to write the driver by myself.

I got the "LDC2114 binding failed." Do you have any idea?

9160_ldc.zip

[Vidar Berg]

Thanks for confirming. Yes, I was wondering if you were writing the driver yourself, or if you used an existing Zephyr driver made by someone else. Regarding the build error, please make sure you are including the <zephyr/devicetree.h> header in your source file. Please note that DEVICE_DT_GET or device_get_binding() should be used in application code to verify whether a driver has been successfully initialized when working with a Zephyr driver which are initialized at startup before the program reaches main(). This is not needed if you are writing the driver in your application.

[Liza]

Hi Vidar,

Vidar Berg said:

Please note that DEVICE_DT_GET or device_get_binding() should be used in application code to verify whether a driver has been successfully initialized when working with a Zephyr driver which are initialized at startup before the program reaches main().

Could I use any existing Zephyr driver without writing the driver by myself in my case (connect LDC2114 to nRF9160DK with I2C)? Because it is difficult to write it. If not, do you have any tutorial about writing my own driver?

Best regards,

Liza

[Vidar Berg]

Hi Liza,

Zephyr does not include a driver for this specific device, unfortunately. You can use the Zephyr i2c driver api directly in your application, or create your own Zephyr driver following the Zephyr driver model. There are many blogs and tutorials for creating zephyr driver. This one for example: https://blog.golioth.io/adding-an-out-of-tree-sensor-driver-to-zephyr/ 

Best regards,

Vidar