Nitrogen Dioxide and Ozone Library API

Modules
	Return codes of the algorithm functions.

Files
file	no2_o3.h
	This file contains the data structure definitions and the function definitions for the NO2 O3 algorithm.

Functions
int8_t	init_no2_o3 (no2_o3_handle_t *handle)
	Initializes the NO2 O3 algorithm. More...
int8_t	calc_no2_o3 (no2_o3_handle_t *handle, const zmod4xxx_dev_t *dev, const no2_o3_inputs_t *algo_input, no2_o3_results_t *results)
	calculates NO2 O3 results from present sample. More...

Data Structures
struct	algorithm_version
	Variables that describe the library version. More...
struct	no2_o3_handle_t
	Variables that describe the sensor or the algorithm state. More...
struct	no2_o3_results_t
	Variables that receive the algorithm outputs. More...
struct	no2_o3_inputs_t
	Variables that are needed for algorithm. More...

Detailed Description

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Data Structure Documentation

algorithm_version

struct algorithm_version

Variables that describe the library version.

Data Fields
uint8_t	major
uint8_t	minor
uint8_t	patch

no2_o3_handle_t

struct no2_o3_handle_t

Variables that describe the sensor or the algorithm state.

Data Fields
uint32_t	sample_counter
float	rmoxs_smooth [4]
float	logrmoxs_mean [4]
float	logrmoxs_var [4]
float	o3_1min_ppb
float	o3_1h_ppb
float	o3_8h_ppb
float	no2_1min_ppb
float	no2_1h_ppb

Field Documentation

sample_counter

uint32_t sample_counter

Sample counter. Will saturate at 0xFFFFFFFF.

no2_o3_results_t

struct no2_o3_results_t

Variables that receive the algorithm outputs.

Data Fields
float	rmox [4]
float	temperature
float	O3_conc_ppb
float	NO2_conc_ppb
uint16_t	FAST_AQI
uint16_t	EPA_AQI

Field Documentation

EPA_AQI

uint16_t EPA_AQI

EPA_AQI stands for the Air Quality Index according to the EPA standard based on ozone.

FAST_AQI

uint16_t FAST_AQI

FAST_AQI stands for a 1-minute average of the Air Quality Index according to the EPA standard based on ozone

NO2_conc_ppb

float NO2_conc_ppb

NO2_conc_ppb stands for the NO2 concentration in part-per-billion

O3_conc_ppb

float O3_conc_ppb

O3_conc_ppb stands for the ozone concentration in part-per-billion

rmox

float rmox[4]

MOx resistance.

temperature

float temperature

Temperature (degC) used for ambient compensation

no2_o3_inputs_t

struct no2_o3_inputs_t

Variables that are needed for algorithm.

Parameters

[in]	adc_result	Value from read_adc_result function
[in]	humidity_pct	relative ambient humidity (%)
[in]	temperature_degc	ambient temperature (degC)

Data Fields
uint8_t *	adc_result
float	humidity_pct
float	temperature_degc

Function Documentation

calc_no2_o3()

int8_t calc_no2_o3	(	no2_o3_handle_t *	handle,
		const zmod4xxx_dev_t *	dev,
		const no2_o3_inputs_t *	algo_input,
		no2_o3_results_t *	results
	)

calculates NO2 O3 results from present sample.

Parameters

[in]	handle	Pointer to algorithm state variable.
[in]	dev	Pointer to the device.
[in]	algo_input	Structure containing inputs required for algo calculation.
[out]	results	Pointer for storing the algorithm results.

Returns

error code.

init_no2_o3()

int8_t init_no2_o3

(

no2_o3_handle_t *

handle

)

Initializes the NO2 O3 algorithm.

Parameters

[out]

handle

Pointer to algorithm state variable.

Returns

error code.