app: sensor: add fetching data from ccs811 and hm3301

Add support for CCS811 air quality sensor and HM3301 particulate
matter sensor to the fire detection system alongside existing BME280.

Changes:
- Add CCS811 (CO2/VOC) and HM3301 (PM1.0/2.5/10) sensor support
- Configure devicetree overlay for multi-sensor I2C bus setup
- Implement environmental compensation for CCS811 using BME280 data
- Add configurable CCS811_ENV_COMPENSATION with smart threshold updates
- Refactor main.c into modular functions for better maintainability
- Enable required sensor drivers in project configuration

The environmental compensation feature improves CCS811 accuracy by
updating its internal registers with temperature and humidity from
BME280, using a 0.5°C/0.5%RH threshold to minimize I2C traffic.

Refs: #9

Signed-off-by: Natalia Pluta <pluta.natalia.m@gmail.com>

Author: nmpluta

app/Kconfig

@@ -10,6 +10,36 @@ menu "Zephyr"
 source "Kconfig.zephyr"
 endmenu
 
+menu "Application Configuration"
+
+config CCS811_ENV_COMPENSATION
+	bool "Enable environmental compensation for CCS811"
+	default y
+	depends on CCS811 && BME280
+	help
+	  Enable updating CCS811 environmental data register with 
+	  temperature and humidity values from BME280 sensor.
+	  This improves accuracy of CO2 and VOC measurements by
+	  compensating for environmental conditions.
+
+config CCS811_DEFAULT_TEMPERATURE
+	int "Fallback temperature for CCS811, Celsius"
+	default 22
+	depends on CCS811_ENV_COMPENSATION
+	help
+	  Default temperature value to use for CCS811 environmental
+	  compensation when BME280 sensor is not available or fails.
+
+config CCS811_DEFAULT_HUMIDITY
+	int "Fallback humidity for CCS811, %RH"
+	default 50
+	depends on CCS811_ENV_COMPENSATION
+	help
+	  Default humidity value to use for CCS811 environmental
+	  compensation when BME280 sensor is not available or fails.
+
+endmenu
+
 module = APP
 module-str = APP
 source "subsys/logging/Kconfig.template.log_config"

app/boards/nrf9160dk_nrf9160.overlay

@@ -25,11 +25,27 @@
 	pinctrl-0 = <&i2c2_default_alt>;
 	pinctrl-1 = <&i2c2_sleep_alt>;
 	pinctrl-names = "default", "sleep";
+	
 	bme280: bme280@77 {
 		compatible = "bosch,bme280";
 		reg = <0x77>;
 		status = "okay";
 	};
+	
+	ccs811: ccs811@5b {
+		compatible = "ams,ccs811";
+		reg = <0x5b>;
+		status = "okay";
+		reset-gpios = <&gpio0 23 GPIO_ACTIVE_LOW>;
+		irq-gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
+		wake-gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;
+	};
+	
+	hm3301: hm3301@40 {
+		compatible = "seeed,hm330x";
+		reg = <0x40>;
+		status = "okay";
+	};
 };
 
 / {

app/prj.conf

@@ -6,7 +6,10 @@
 CONFIG_LOG=y
 CONFIG_BLINK=y
 
-# Enable I2C and sensor subsystem for BME280
+# Enable I2C and sensor subsystem for multiple sensors
 CONFIG_I2C=y
 CONFIG_SENSOR=y
 CONFIG_BME280=y
+CONFIG_CCS811=y
+CONFIG_CCS811_ENV_COMPENSATION=y
+CONFIG_HM330X=y