Asset Tracker - adding SPI sensor

[spline_pete]

Using: Windows 10, nRF Connect v3.5.0, SES v4.52, ncs v1.3.0, zephyr v2.3.0

I have a custom board based on the Thingy91 and the Asset Tracker application. There is also an LIS2DW12 present on SPI.  In prj.conf, I added these lines:

CONFIG_SENSOR=y
CONFIG_TEMP_USE_EXTERNAL=y
CONFIG_TEMP_USE_SIM=n
CONFIG_SENSOR_SIM=n
CONFIG_SPI=y
CONFIG_SPI_NRFX=y
CONFIG_SPI_3=y
CONFIG_ACCEL_USE_EXTERNAL=y
CONFIG_LIS2DW12=y
CONFIG_ACCEL_DEV_NAME="LIS2DW12"
CONFIG_LIS2DW12_ODR_1_6=y
CONFIG_LIS2DW12_ACCEL_RANGE_2G=y

I modified the Thingy91 board file thingy91_nrf9160_common.dts:

&spi3 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	sck-pin = <16>;
	mosi-pin = <13>;
	miso-pin = <14>;
	cs-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;

	lis2dw12 {
		compatible = "stm,lis2dw12";
		label = "LIS2DW12";
		spi-max-frequency = <10000000>;
		int1-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>;
	};
};

In lis2dw12.c, I added these lines to the top:

#define DT_DRV_COMPAT stm_lis2dw12
#define LIS2DW12	DT_INST(0, stm_lis2dw12)

In SES, it builds quite far, but I get an error:

C:/engr/ncs/v1.3.0/zephyr/drivers/sensor/lis2dw12/lis2dw12.c:227: undefined reference to `lis2dw12_spi_init'

In lis2dw12.c, this section is grayed out:

#if DT_ANY_INST_ON_BUS_STATUS_OKAY(spi)
#include <drivers/spi.h>
#elif DT_ANY_INST_ON_BUS_STATUS_OKAY(i2c)
#include <drivers/i2c.h>
#endif

Which means it never includes the spi.h file.  What am I missing?  Any ideas?

[Simon]

I see that you're getting undefined reference to lis2dw12_spi_init() on line 227, which means that the DTS overlay is ok (since

DT_ANY_INST_ON_BUS_STATUS_OKAY(spi) is true and it tries to access lis2dw12_spi_init()), 

#if DT_ANY_INST_ON_BUS_STATUS_OKAY(spi)
	lis2dw12_spi_init(dev);
#elif DT_ANY_INST_ON_BUS_STATUS_OKAY(i2c)
	lis2dw12_i2c_init(dev);
#else

but there are some issues with the driver.

Could you try to swap

#define DT_DRV_COMPAT st_lis2dw12

with

#define DT_DRV_COMPAT stm_lis2dw12

At the top of zephyr\drivers\sensor\lis2dw12\lis2dw12_spi.c?

Best regards,

Simon

[spline_pete]

In the third code block, the #define in lis2dw12.c is already that way (see above):

#define DT_DRV_COMPAT stm_lis2dw12

The fourth code block is all grayed out, not the function lis2dw12_spi_init().  This means DT_ANY_INST_ON_BUS_STATUS_OKAY is false.

[spline_pete]

Hi, Simon. Did you find anything?

[Simon]

I got rid of the "undefined reference" by doing what I suggested earlier. Be aware that I said you should change zephyr\drivers\sensor\lis2dw12\lis2dw12_spi.c and not zephyr\drivers\sensor\lis2dw12\lis2dw12.c.

However, when I fixed that issue, many DTS related errors showed up.

I see that you are using the compatible string "stm,lis2dw12", but I could not find any bindings for it under zephyr\dts\bindings\sensor. The bindigs defines what should be included in a DTS node where this compatible is used. Read about it here.

Why don't you just use the already present "st,lis2dw12"? If for some reason you want to create your own, you should create a new a yaml file similar to this one: zephyr\dts\bindings\sensor\st,lis2dw12-spi.yaml.

By the way, it is good practice to create a new board folder for you custom board, and not modify existing ones. The naming convention should be <board name>_<chip name>, e.g. myboard_nrf9160. Take a look at 2. Using a custom board with NCS for instructions how to do this.

Best regards,

Simon

[spline_pete]

I wasn't trying to create my own driver, it just wasn't obvious to me what the compatible name should be.  I'll try "st" instead of "stm".

I intend to restore the original board files and use my own once I get further.  I was just having so many problems.  So I started from a known-good state and slowly introduced changes to minimize/eliminate errors. 

Thanks.

[Simon]

Okay, I see  I probably should have warned you against modifying the DT_DRV_COMPAT of the driver at an earlier point. My apologies for that.

But hopefully you're able to get it to work now.

Best regards,

Simon

[spline_pete]

I updated the compatible name in "thingy91_nrf9160_common.dts":

&spi3 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	sck-pin = <16>;
	mosi-pin = <13>;
	miso-pin = <14>;
	cs-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;

	lis2dw12 {
		compatible = "st,lis2dw12";
		label = "LIS2DW12";
		spi-max-frequency = <8000000>;
		int1-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>;
	};
};

While the project is loading, I get this error:

<stdout>: Warning (avoid_unnecessary_addr_size): /soc/peripheral@40000000/spi@b000: unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
devicetree error: 'reg' is marked as required in 'properties:' in C:/engr/ncs/v1.3.0/zephyr/dts/bindings\sensor\st,lis2dw12-spi.yaml, but does not appear in <Node /soc/peripheral@40000000/spi@b000/lis2dw12 in 'thingy91_nrf9160ns.dts.pre.tmp'>

I added "reg = <0>;" after the "spi-max-frequency" line (similar to the original ADXL3x2 sensors) and now I get this error while loading:

<stdout>: ERROR (unit_address_vs_reg): /soc/peripheral@40000000/spi@b000/lis2dw12: node has a reg or ranges property, but no unit name

Where would I even learn about which sensor fields are required and the required format, attributes, etc.?

Does configuring a Thingy91 with a LIS2DW12 work for you? 

[Simon]

Could you try to apply this patch to the nrf repository: asset_tracker_thingy91_lis2dw12.patch

I went against my own advice and modified the Thingy:91 board folder directly

I'm not at the office until Monday and don't have access to a Thingy:91 until then, so I have not tested the example. But it builds successfully.

Best regards,

Simon

[spline_pete]

Ok, I'll try it...

[spline_pete]

It builds!

Thanks!

[Simon]

Nice! I'm happy it works.