How to connect nrf9160 with multiple bme280 sensor?

[PoNien Su]

Hello!

I have followed nrf connect sdk tutorial part3 and have walked through for bme280. But now I want to connect two or more bme280 sensors to my dk. How should I modify the prj.conf file, the overlay file and the main.c file?

Thanks a lot.

Regards

PoNien Su

[Albrecht Markus Schellenberger]

Hello PoNien Su,

Here is an example of how you can connect three BM280 sensors to the nRF9160 DK using the I2C-interface.

Since the device addresses of the BME280 are limited to 0x76 and 0x77, you can connect two sensors to one I2C-bus and the third to an additional one.

Your overlay file will then look like this:

&i2c2 {
	bme280_76@76 {
		compatible = "bosch,bme280";
		reg = <0x76>;
		label = "BME280_76";
	};
	bme280@77 {
		compatible = "bosch,bme280";
		reg = <0x77>;
		label = "BME280";
	};
};

&i2c3 {
	sda-pin = < 0x12 >;
	scl-pin = < 0x11 >;
	compatible = "nordic,nrf-twim";
	status = "okay";	
	bme280_i2c3@77 {
		compatible = "bosch,bme280";
		reg = <0x77>;
		label = "BME280_I2C3";
	};
};

&spi3 {
	status = "disabled";
};

Be aware that due to memory instantiation, you have to disable the SPI3 interface. See:

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf9160%2Fmemory.html&anchor=topic

Make sure that you are using the following options in prj.conf:

 

CONFIG_I2C=y
CONFIG_SENSOR=y
CONFIG_BME280=y

You can now use the sensors in main.c in the same way as demonstrated in the tutorial.

I hope this will help you! Let me know if you have any more questions.

Regards,

Markus