GY-63_MS5611/libraries/MINMAX

MINMAX

Library for finding peaks (minimum and maximum) in a signal.

Description

The MINMAX library is a simple peak finder in a stream of floats.

The add() function indicates after adding a number if the minimum and/or the maximum value has been changed by means of a bit flag that is returned. If a peak is found, it will be used as the new reference until a call to reset().

The library can reset() the minimum and maximum to 0 to start again.

The library has also the option to auto-reset after a predefined number of add() calls.

lastMin() timestamp in millis() when minimum was last updated. lastMax() timestamp in millis() when maximum was last updated.

Interface

• MINMAX Constructor,
• uint8_t add(float value) add next value. Returns status (bit flags), see table below.
• void reset() resets the minimum and maximum to 0.
• void setAutoResetCount(uint32_t count) sets an auto-reset moment after count calls to add().
  There will be at least one value processed.
• uint32_t getAutoResetCount() returns set value.
• float minimum() returns last minimum. Can be higher than previous call due to reset() or autoReset().
  If no call to add() is made yet it will return 0.
• float maximum() returns last maximum. Can be lower than previous call due to reset() or autoReset().
  If no call to add() is made yet it will return 0.
• uint32_t count() returns number of add() calls since last (auto)reset.

Return flags of add() - is a bit mask.

flag	value	description
MINMAX_NO_CHANGE	0x00	no change
MINMAX_MIN_CHANGED	0x01	minimum changed
MINMAX_MAX_CHANGED	0x02	maximum changed
MINMAX_RESET_DONE	0x80	reset done

NOTE: After a reset() the next add() will return both MINMAX_MIN_CHANGED and MINMAX_MAX_CHANGED (0x03)

Obsolete

• void autoReset(uint32_t count) obsolete, replaced by void setAutoResetCount()

Operation

The examples show the basic working of the functions.

Future

must

• update documentation.

should

• move code to .cpp (0.2.0)

could

• define FLAGS
• add call back functions?
• thresholds, windowing + triggers (separate class?)
• auto-reset after time? (would affect all functions ?)
  • need a uint32_t start;
  • need a uint32_t threshold;
  • millis() - start > threshold) => action.
• Template class to allow other types
  • int32_t uint64_t double etc.
  • now you loose precision
• add AVG average() _sum / _count (like a DMM)