adapnex::core::Hysteresis

Switches a boolean output based on two analog thresholds.

Synopsis

Declared in <adapnex/core/hysteresis.h>

template<typename T>
class Hysteresis;

Description

Implements hysteresis to prevent rapid switching when an input signal fluctuates near a threshold.

The block automatically adapts its logic based on the relationship between SET and RESET:

Direct (e.g. Cooling/High‐Alarm): If SET > RESET, OUT becomes true when IN rises above SET, and false when IN falls below RESET.
Inverse (e.g. Heating/Low‐Alarm): If SET <= RESET, OUT becomes true when IN falls below SET, and false when IN rises above RESET.

Hysteresis Logic Diagram

Parameter Type Direction Description

Parameter	Type	Direction	Description
`IN`	`T`	Input	The signal to evaluate.
`SET`	`T`	Input	Crossing this threshold sets `OUT` to `true`.
`RESET`	`T`	Input	Crossing this threshold resets `OUT` to `false`.
`OUT`	`bool`	Output	The switching result based on the hysteresis logic.

IN

T

Input

The signal to evaluate.

SET

T

Input

Crossing this threshold sets OUT to true.

RESET

T

Input

Crossing this threshold resets OUT to false.

OUT

bool

Output

The switching result based on the hysteresis logic.

Common Use Case

Thermostat controlling a cooling fan or heating system to prevent short cycling.

Example: Temperature Control

class CoolingSystem : public Task {
public:
    float current_temp = 0.0f;
    bool fan_active = false;

private:
    Hysteresis<float> temp_switch;

    void Update() override {
        // SET > RESET implies high threshold logic (turn ON at 30.0, turn OFF at 25.0).
        temp_switch(current_temp, 30.0f, 25.0f, fan_active);
    }
};

Both SET > RESET and SET < RESET are allowed. The implementation adapts the comparisons accordingly.

Hysteresis blocks maintain state across cycles and must be instantiated as member variables of a task rather than locally within Update().