Lightning Class Reference

Calculation number of lightning events during last sensor update cycle and during last hour (past 60 minutes); storing timestamp and distance of last event. More...

#include <Lightning.h>

Public Member Functions
	Lightning (const float quality_threshold=DEFAULT_QUALITY_THRESHOLD)
void	setUpdateRate (uint8_t rate=LIGHTNING_UPD_RATE)
	Set expected update rate for pastHour() calculation.
void	reset (void)
void	hist_init (int16_t count=-1)
void	prefs_load (void)
void	prefs_save (void)
void	update (time_t timestamp, int16_t count, uint8_t distance, bool startup=false)
	Update lightning data.
int	pastHour (bool *valid=nullptr, int *nbins=nullptr, float *quality=nullptr)
	Get number of lightning events during past 60 minutes.
int	lastCycle (void)
bool	lastEvent (time_t &timestamp, int &events, uint8_t &distance)

Detailed Description

Calculation number of lightning events during last sensor update cycle and during last hour (past 60 minutes); storing timestamp and distance of last event.

Constructor & Destructor Documentation

Lightning()

Lightning::Lightning ( const float  quality_threshold = DEFAULT_QUALITY_THRESHOLD )

inline

Constructor

Parameters

quality_threshold

fraction of valid hist entries required for valid pastHour() result

Member Function Documentation

hist_init()

void Lightning::hist_init

(

int16_t

count = -1

)

Initialize histogram of hourly (past 60 minutes) events

Parameters

count

number of events

pastHour()

Lightning::pastHour	(	bool *	valid = nullptr,
		int *	nbins = nullptr,
		float *	quality = nullptr
	)

Get number of lightning events during past 60 minutes.

Parameters

valid	number of valid entries in hist >= qualityThreshold * 60 / updateRate
nbins	number of valid entries in hist
quality	fraction of valid entries in hist (0..1); quality = nbins / (60 / updateRate)

Returns

number of events during past 60 minutes

reset()

void Lightning::reset

(

void

)

Initialize/reset non-volatile data

setUpdateRate()

void Lightning::setUpdateRate ( uint8_t  rate = LIGHTNING_UPD_RATE )

inline

Set expected update rate for pastHour() calculation.

LIGHTNING_HIST_SIZE: number of entries in hist[] updateRate: update rate in minutes

60 minutes / updateRate = no_of_hist_bins The resulting number of history bins must be an integer value which does not exceed LIGHTNING_HIST_SIZE.

Examples:

1. updateRate = 6 -> 60 / 6 = 10 entries
2. updateRate = 12 -> 60 / 12 = 5 entries

Changing the update rate will reset the history buffer, therefore the caller should avoid frequent changes.

Actual update intervals shorter than updateRate will lead to a reduced resolution of the pastHour() result and a higher risk of an invalid result if a bin in the history buffer was missed.

Actual update intervals longer than updateRate will lead to an invalid result, because bins in the history buffer will be missed.

Parameters

rate	update rate in minutes (default: 6)

update()

Lightning::update	(	time_t	timestamp,
		int16_t	count,
		uint8_t	distance,
		bool	startup = false
	)

Update lightning data.

Parameters

timestamp	timestamp (epoch)
count	accumulated number of events
startup	sensor startup flag
lightningCountMax	overflow value; when reached, the sensor's counter is reset to zero

* Total number of events during past 60 minutes
* ----------------------------------------------
* 
* In each update():
* - timestamp (time_t) ->                  t (localtime, struct tm)
* - calculate index into hist[]:           idx = t.tm_min / updateRate
* - expired time since last update:        t_delta = timestamp - nvLightning.lastUpdate
* - number of events since last update:    delta = currCount - nvLightning.prevCount
* - t_delta
*      < 0:                                something is wrong, e.g. RTC was not set correctly -> ignore, return
*      t_delta < expected update rate:
*          idx same as in previous cycle:  hist[idx] += delta
*          idx changed by 1:               hist[idx] = delta
*      t_delta >= history size:            mark all history entries as invalid
*      else (index changed > 1):           mark all history entries in interval [expected_index, current_index) as invalid
*                                          hist[idx] = delta
*
*   ---------------     -----------
*  |   |   |   |   |...|   |   |   |   hist[LIGHTNING_HIST_SIZE]
*   ---------------     -----------
*        ^
*        |
*       idx = t.tm_min / updateRate
*
* - Calculate hourly rate:
*   pastHour = sum of all valid hist[] entries
*
* 

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The documentation for this class was generated from the following files:

• src/Lightning.h
• src/Lightning.cpp