BME680 sample on nRF5340

[langestefann]

Hi, 

I am trying to interface a BME680 sensor with my nRF5340 DK. I am trying to get the following sample to run (I left everything default): https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/samples/sensor/bme680/README.html

When building I get the following error:

'DT_N_INST_0_bosch_bme680_P_label' undeclared (first use in this function)

Is there anything specific I need to configure? I'm not sure what to do, this is quite new to me.

Kind regards,

Stefan

[bigbear]

Yes, you need to configure the device tree overlay for your board. Go to the sample folder -> boards and check out the pre-configured overlay files. 

Assuming that you are using the nrf5340dk and building on the cpuapp-core, create an overlay file nrf5340dk_nrf5340_cpuapp.overlay inside the boards folder. You can copy the content from the nrf52840dk overlay file, but change &i2c0 to &i2c1 because that is the one which the cpuapp core is using.

After that the example should build.

[langestefann]

That seems to have done the trick, it compiles now, thank you! But I am a little bit confused, why did you use cpuapp and not cpuappns ? Thanks a lot!

[bigbear]

I guess you can use either cpuapp or cpuappns, depending if you want to execute from the secure area or not. 

[langestefann]

I just tested this, it leads to the same error again. I even tried renaming nrf5340dk_nrf5340_cpuapp.overlay to nrf5340dk_nrf5340_cpuappns.overlay but that didn't help. Not sure if this has something to do with how it's being compiled or it can't find the overlay file if I switch to non secure?  

[bigbear]

I just tried, for me it actually compiles after renaming the overlay file. Have you deleted the build folder before running west build?

Is there a particular reason why you want to use non-secure?

[langestefann]

That indeed did the trick. I thought the 'clean solution' command removed that folder but I guess it didn't do it (completely). 

Now for the next challenge. I now see the following output looping:

*** Booting Zephyr OS build v2.4.99-ncs1  ***
Device (nil) name is <
*** Booting Zephyr OS build v2.4.99-ncs1  ***
Device (nil) name is <
*** Booting Zephyr OS build v2.4.99-ncs1  ***
Device (nil) name is <

It seems like it is not reading the overlay file properly? And then it reboots with no error.

These are the contents of the overlay file:

nrf5340dk_nrf5340_cpuapp.overlay

/*
 * Copyright (c) 2020, Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */

&i2c1 {
	compatible = "nordic,nrf-twim";
	status = "okay";
	sda-pin = < 30 >; //P0.30
	scl-pin = < 31 >; //P0.31
    clock-frequency = <I2C_BITRATE_STANDARD>; 
	
	bme680@76 {
		compatible = "bosch,bme680";
		reg = <0x76>;
		label = "BME680";
	};
};