Components

Components are C++ classes that use store objects for input/output/parameters/control. This let’s you easily tune and debug an application.

The instances of these classes are tuned at compile-time to reflect the objects in the store. Especially, no resources are used for (optional) fields that do not exist in the store, and all store lookups in the directory are done at compile-time. You need C++14 (or later), though.

Check out the components and control examples.

stored::Amplifier

template<typename Container, unsigned long long flags = 0, typename T = float> class Amplifier

An offset/gain amplifier, based on store variables.

This class comes in very handy when converting ADC inputs to some SI-value. It includes an override field to force inputs to some test value.

To use this class, add a scope to your store, like:

{
    float input
    bool=true enable
    float=1 gain
    float=0 offset
    float=-inf low
    float=inf high
    float=nan override
    float output
} amp

All fields are optional. All variables of type float can be any other type, as long as it matches the template parameter T.

When not all fields are in the store, names may become ambiguous. For example, if override and output are not there, the store’s directory may resolve o to any of the three fields. In this case, you have to specify which fields are to be processed. For this, use the following ids:

field	id
input	`I`
enable	`e`
gain	`g`
offset	`o`
low	`l`
high	`h`
override	`F`
output	`O`

The amplifier basically does:

if(override is nan)
    output = min(high, max(low, input * gain + offset))
else
    output = override

Then, instantiate the amplifier like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto amp_o = stored::Amplifier<stored::YourStore>::objects("/amp/");

// Instantiate an Amplifier, tailored to the available fields in the store.
stored::Amplifier<stored::YourStore, amp_o.flags()> amp{amp_o, yourStore};

Or, for example when you know there are only the offset and gain fields in the store, and ambiguity must be resolved:

// Construct a compile-time object, which resolves only two fields in your store.
constexpr auto amp_o = stored::Amplifier<stored::YourStore>::objects<'o','g'>("/amp/");
stored::Amplifier<stored::YourStore, amp_o.flags()> amp{amp_o, yourStore};

Calling amp() now uses the input and produces the value in output. Alternatively, or when the input field is absent in the store, call amp(x), where x is the input.

Public Types

using Bound = typename AmplifierObjects<Container, type>::template Bound<flags>

using type = T 

Public Functions

constexpr Amplifier() noexcept = default

Default ctor.

Use this when initialization is postponed. Do not access or run the Amplifier instance, as it does not hold proper references to a store. You can just assign another Amplifier instance.

inline constexpr Amplifier(AmplifierObjects<Container, type> const &o, Container &container): Initialize the Amplifier, given a list of objects and a container.

inline void disable() noexcept

Disable the Amplifier.

Ignored when the enable object is not available.

inline void enable(bool value = true) noexcept

Enable (or disable) the Amplifier.

Ignored when the enable object is not available.

inline bool enabled() const noexcept: Return the enable value, which is true when not available.

inline decltype(auto) enableObject() const noexcept: Return the enable object.

inline decltype(auto) enableObject() noexcept: Return the enable object.

inline type gain() const noexcept: Return the gain value, or 1 when not available.

inline decltype(auto) gainObject() const noexcept: Return the gain object.

inline decltype(auto) gainObject() noexcept: Return the gain object.

inline type high() const noexcept: Return the high value, or inf when not available.

inline decltype(auto) highObject() const noexcept: Return the high object.

inline decltype(auto) highObject() noexcept: Return the high object.

inline type input() const noexcept: Return the input value, or 0 when not available.

inline decltype(auto) inputObject() const noexcept: Return the input object.

inline decltype(auto) inputObject() noexcept: Return the input object.

inline type low() const noexcept: Return the low value, or -inf when not available.

inline decltype(auto) lowObject() const noexcept: Return the low object.

inline decltype(auto) lowObject() noexcept: Return the low object.

inline type offset() const noexcept: Return the offset value, or 1 when not available.

inline decltype(auto) offsetObject() const noexcept: Return the offset object.

inline decltype(auto) offsetObject() noexcept: Return the offset object.

inline type operator()() noexcept: Compute the Amplifier output, given the input as stored in the store.

inline type operator()(type input) noexcept: Compute the Amplifier output, given an input.

inline type output() const noexcept: Return the output value, or 0 when not available.

inline decltype(auto) outputObject() const noexcept: Return the output object.

inline decltype(auto) outputObject() noexcept: Return the output object.

inline type override_() const noexcept: Return the override value, or NaN when not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

stored::FirstOrderFilter

template<typename Container, bool LowPass, unsigned long long flags = 0, typename T = float> class FirstOrderFilter

First-order low- or high-pass filter, based on store variables.

To use this class, add a scope to your store, like:

{
    (float) sample frequency (Hz)
    float input
    float cutoff frequency (Hz)
    bool=true enable
    bool reset
    float=nan override
    float output
} filter

Only sample frequency and cutoff frequency are mandatory. All variables of type float, except for sample frequency, can be any other type, as long as it matches the template parameter T.

Then, instantiate the controller like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto filter_o = stored::LowPass<stored::YourStore>::objects("/filter/");

// Instantiate the filter, tailored to the available fields in the store.
stored::LowPass<stored::YourStore, filter_o.flags()> filter{filter_o, yourStore};

// ...or use HighPass instead of LowPass.

The cutoff frequency can be changed while running (by setting reset to true). It will applied smoothly; the output will gradually take the new cutoff frequency into account.

Public Types

using Bound = typename FirstOrderFilterObjects<Container, type>::template Bound<flags>

using type = T 

Public Functions

constexpr FirstOrderFilter() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr FirstOrderFilter(FirstOrderFilterObjects<Container, type> const &o, Container &container): Initialize the filter, given a list of objects and a container.

inline type cutoffFrequency() const noexcept: Return the cutoff frequency value.

inline decltype(auto) cutoffFrequencyObject() const noexcept: Return the cutoff frequency object.

inline decltype(auto) cutoffFrequencyObject() noexcept: Return the cutoff frequency object.

inline void disable() noexcept

Disable the pulse wave.

Ignored when the enable object is not available.

inline void enable(bool value = true) noexcept

Enable (or disable) the pulse wave.

Ignored when the enable object is not available.

inline bool enabled() const noexcept: Return the enable value, or true when not available.

inline decltype(auto) enableObject() const noexcept: Return the enable object.

inline decltype(auto) enableObject() noexcept: Return the enable object.

inline type input() const noexcept: Return the input value, or 0 when not available.

inline decltype(auto) inputObject() const noexcept: Return the input object.

inline decltype(auto) inputObject() noexcept: Return the input object.

inline type lastInput() const noexcept: Return the last input to the filter.

inline type lastOutput() const noexcept: Return the last output of the filter.

inline type operator()() noexcept: Compute filter output, given the input stored in the store.

inline type operator()(type input) noexcept: Compute filter output, given an input.

inline type output() const noexcept: Return the output value, or 0 when not available.

inline decltype(auto) outputObject() const noexcept: Return the output object.

inline decltype(auto) outputObject() noexcept: Return the output object.

inline type override_() const noexcept: Return the override value, or NaN when not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

inline void recomputeCoefficients(): Recompute alpha after changed filter parameters.

inline bool reset() const noexcept: Return the reset value, or false when not available.

inline decltype(auto) resetObject() const noexcept: Return the reset object.

inline decltype(auto) resetObject() noexcept: Return the reset object.

inline float sampleFrequency() const noexcept: Return the sample frequency.

inline decltype(auto) sampleFrequencyObject() const noexcept: Return the sample frequency object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

There are stored::LowPass and stored::HighPass aliases for the corresponding stored::FistOrderFilter template parameters.

stored::PID

template<typename Container, unsigned long long flags = 0, typename T = float> class PID

PID controller, based on store variables.

To use this class, add a scope to your store, like:

{
    (float) frequency (Hz)
    float y
    float setpoint
    bool=true enable
    float=1 Kp
    float=inf Ti (s)
    float=0 Td (s)
    float=0 Kff
    float int
    float=-inf int low
    float=inf int high
    float=-inf low
    float=inf high
    float=inf error max
    float=inf epsilon
    bool reset
    float=nan override
    float u
} pid

Only frequency, setpoint, and Kp are mandatory. All variables of type float, except for frequency, can be any other type, as long as it matches the template parameter T.

It has the following objects:

frequency: the control frequency; the application must invoke the PID controller at this frequency
y: the process variable (output of the plant)
setpoint: the setpoint to control y to
Kp: P coefficient
Ti: I time constant
Td: D time constant
Kff: feed-forward coefficient
int: current integral value
int low: lower bound for int
int high: upper bound for int
low: lower bound for computed u
high: upper bound for computed u
epsilon: minimum value of the error ( | setpoint - y | ), which must result in a change of the output u. Otherwise, numerical stability is compromised. See isHealthy().
reset: when set to true, recompute and apply changed control parameters
override: when not NaN, force u to this value, without low and high applied
u: control output (input for the plant)

Then, instantiate the controller like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto pid_o = stored::PID<stored::YourStore>::objects("/pid/");

// Instantiate a PID, tailored to the available fields in the store.
stored::PID<stored::YourStore, pid_o.flags()> pid{pid_o, yourStore};

The PID controller has the following properties:

The parameters specify a serial PID.
The integral windup prevention stops the integral when the output clips.
Changing Ti is implemented smoothly; changing the parameters (and setting reset afterwards) can be done while running.
isHealthy() checks for numerical stability.

Public Types

using Bound = typename PIDObjects<Container, type>::template Bound<flags>

using type = T 

Public Functions

constexpr PID() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr PID(PIDObjects<Container, type> const &o, Container &container): Initialize the pin, given a list of objects and a container.

inline void disable() noexcept

Disable the PID.

Ignored when the enable object is not available.

inline void enable(bool value = true) noexcept

Enable (or disable) the PID.

Ignored when the enable object is not available.

inline bool enabled() const noexcept: Return the enable value, or true when not available.

inline decltype(auto) enableObject() const noexcept: Return the enable object.

inline decltype(auto) enableObject() noexcept: Return the enable object.

inline type epsilon() const noexcept: Return the epsilon value, or inf when not available.

inline decltype(auto) epsilonObject() const noexcept: Return the epsilon object.

inline decltype(auto) epsilonObject() noexcept: Return the epsilon object.

inline type errorMax() const noexcept: Return the error max value, or inf when not available.

inline decltype(auto) errorMaxObject() const noexcept: Return the error max object.

inline decltype(auto) errorMaxObject() noexcept: Return the error max object.

inline float frequency() const noexcept: Return the control frequency.

inline decltype(auto) frequencyObject() const noexcept: Return the frequency object.

inline type high() const noexcept: Return the high value, or inf when not available.

inline decltype(auto) highObject() const noexcept: Return the high object.

inline decltype(auto) highObject() noexcept: Return the high object.

inline type int_() const noexcept

Return the current integral value.

This is the integral of the (setpoint - y) * Ki. So, when Ti (and there fore Ki) changes, it may take a while till the new Ti is in effect, depending on the current integral value.

inline type intHigh() const noexcept: Return the int high vale, or inf when not available.

inline decltype(auto) intHighObject() const noexcept: Return the int high object.

inline decltype(auto) intHighObject() noexcept: Return the int high object.

inline type intLow() const noexcept: Return the int low value, or -inf when not available.

inline decltype(auto) intLowObject() const noexcept: Return the int low object.

inline decltype(auto) intLowObject() noexcept: Return the int low object.

inline decltype(auto) intObject() const noexcept: Return the int object.

inline decltype(auto) intObject() noexcept: Return the int object.

inline bool isHealthy() const noexcept

Check numerical stability.

epsilon() is the smallest change in error ( | setpoint() - y() | ) that must have influence the output u(). If the error is smaller, the output may remain the same. This function checks if that is still the case.

The integrator is especially interesting. If it becomes too large, successive (small) errors may not be able to reduce it anymore, because of rounding. If that is the case, it is considered unhealthy.

This value can optionally be defined in the store. If omitted, this function always returns true.

You may want to check (or assert on) this function once in a while, like once per second or after every run, to detect a stuck controller within reasonable time for your application.

inline type Kd() const noexcept: Return the computed Kd value.

inline type Kff() const noexcept: Return the Kff value, or 0 when not available.

inline decltype(auto) KffObject() const noexcept: Return the Kff object.

inline decltype(auto) KffObject() noexcept: Return the Kff object.

inline type Ki() const noexcept: Return the computed Ki value.

inline type Kp() const noexcept: Return the Kp value.

inline decltype(auto) KpObject() const noexcept: Return the Kp object.

inline decltype(auto) KpObject() noexcept: Return the Kp object.

inline type low() const noexcept: Return the low value, or -inf when not available.

inline decltype(auto) lowObject() const noexcept: Return the low object.

inline decltype(auto) lowObject() noexcept: Return the low object.

inline type operator()() noexcept: Compute the PID output, given the y as stored in the store.

inline type operator()(type y) noexcept: Compute the PID output, given a y.

inline type override_() const noexcept: Return the override value, or NaN when not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

inline bool reset() const noexcept: Return the reset value, or false when not available.

inline decltype(auto) resetObject() const noexcept: Return the reset object.

inline decltype(auto) resetObject() noexcept: Return the reset object.

inline type setpoint() const noexcept: Return the setpoint value.

inline decltype(auto) setpointObject() const noexcept: Return the setpoint object.

inline decltype(auto) setpointObject() noexcept: Return the setpoint object.

inline type Td() const noexcept: Return the Td value, or 0 when not available.

inline decltype(auto) TdObject() const noexcept: Return the Td object.

inline decltype(auto) TdObject() noexcept: Return the Td object.

inline type Ti() const noexcept: Return the Ti value, or inf when not available.

inline decltype(auto) TiObject() const noexcept: Return the Ti object.

inline decltype(auto) TiObject() noexcept: Return the Ti object.

inline type u() const noexcept: Return the u value, with the override applied.

inline decltype(auto) uObject() const noexcept: Return the u object.

inline decltype(auto) uObject() noexcept: Return the u object.

inline type y() const noexcept: Return the y value, or 0 when not available.

inline decltype(auto) yObject() const noexcept: Return the y object.

inline decltype(auto) yObject() noexcept: Return the y object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

stored::PinIn

template<typename Container, unsigned long long flags = 0> class PinIn

An GPIO input pin, based on store variables.

This class comes in very handy when a GPIO input should be observed and overridden while debugging. It gives some interface between the hardware pin and the input that the application sees.

To use this class, add a scope to your store, like:

{
    (bool) pin
    int8=-1 override
    bool input
    (bool) get
} pin

All fields are optional. You can implement the store’s pin function, override the virtual pin() function of the PinIn class, or pass the hardware pin value as an argument to the PinIn::operator().

The pin basically does:

switch(override) {
case -1: input = pin; break;
case  0: input = false; break;
case  1: input = true; break;
case  2: input = !pin; break;
}

Then, instantiate the pin like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto pin_o = stored::PinIn<stored::YourStore>::objects("/pin/");

// Instantiate an PinIn, tailored to the available fields in the store.
stored::PinIn<stored::YourStore, pin_o.flags()> pin{pin_o, yourStore};

When pin() is called, it will invoke the pin function to get the actual hardware pin status. Then, it will set the input variable.

The get function is not used/provided by this PinIn. Implement this store function such that it calls and returns pin(). When applications read the get function, they will always get the appropriate/actual pin value.

Public Types

using Bound = typename PinInObjects<Container>::template Bound<flags>

Public Functions

constexpr PinIn() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr PinIn(PinInObjects<Container> const &o, Container &container): Initialize the pin, given a list of objects and a container.

virtual ~PinIn() = default: Dtor.

template<char I = 'i', std::enable_if_t<Bound::template has<I>(), int> = 0> inline bool input() const noexcept: Return the last computed input value, or compute the pin state when the object is not available.

template<char I = 'i', std::enable_if_t<!Bound::template has<I>(), int> = 0> inline bool input() noexcept: Return the last computed input value, or compute the pin state when the object is not available.

inline decltype(auto) inputObject() const noexcept: Return the input object.

inline decltype(auto) inputObject() noexcept: Return the input object.

inline bool operator()() noexcept: Determine pin input, given the current hardware state.

inline bool operator()(bool pin) noexcept: Determine pin input, given the provided hardware state.

inline int8_t override_() const noexcept: Return the override value, or -1 when the object is not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

inline virtual bool pin() const noexcept

Return the hardware pin value.

By default, it calls the pin function in the store. Override in a subclass to implement other behavior.

inline decltype(auto) pinObject() const noexcept: Return the pin object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

stored::PinOut

template<typename Container, unsigned long long flags = 0> class PinOut

An GPIO output pin, based on store variables.

This class comes in very handy when a GPIO output should be observed and overridden while debugging. It gives some interface between the hardware pin and the output that the application wants.

To use this class, add a scope to your store, like:

{
    (bool) set
    bool output
    (int8) override
    (bool) pin
} pin

All fields are optional, except output. You can implement the store’s pin function, override the virtual pin() function of the PinOut class, or forward the return value of PinOut::operator() to the hardware pin.

The pin basically does:

switch(override) {
case -1: pin = output; break;
case  0: pin = false; break;
case  1: pin = true; break;
case  2: pin = !output; break;
}

Then, instantiate the pin like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto pin_o = stored::PinOut<stored::YourStore>::objects("/pin/");

// Instantiate an PinOut, tailored to the available fields in the store.
stored::PinOut<stored::YourStore, pin_o.flags()> pin{pin_o, yourStore};

The set function is not used/provided by this PinOut. Implement this store function such that it calls pin() with the provided value. When applications write the set function, they will immediately control the hardware pin.

Similar holds for the override function; implement it to call the override_() of PinOut. This way, if one sets the override value, the hardware pin is updated accordingly.

Public Types

using Bound = typename PinOutObjects<Container>::template Bound<flags>

Public Functions

constexpr PinOut() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr PinOut(PinOutObjects<Container> const &o, Container &container): Initialize the pin, given a list of objects and a container.

virtual ~PinOut() = default: Dtor.

inline bool operator()() noexcept: Compute and set the hardware pin status, given the last provided application’s output value.

inline bool operator()(bool output) noexcept: Compute and set the hardware pin status, given the application’s output value.

inline bool output() const noexcept: Return the output value.

inline decltype(auto) outputObject() const noexcept: Return the output object.

inline decltype(auto) outputObject() noexcept: Return the output object.

inline int8_t override_() const noexcept: Return the override value.

inline void override_(int8_t x) noexcept: Set the override value.

inline virtual void pin(bool value) noexcept

Set the hardware pin state.

The default implementation calls the store’s pin function. Override in a subclass to implement custom behavior.

inline decltype(auto) pinObject() noexcept: Return the pin object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

stored::PulseWave

template<typename Container, unsigned long long flags = 0, typename T = float> class PulseWave

Pulse wave generator, based on store variables.

To use this class, add a scope to your store, like:

{
    (float) sample frequency (Hz)
    float=1 amplitude
    float=1 frequency (Hz)
    float=0 phase (rad)
    float=0.5 duty cycle
    bool=true enable
    float=nan override
    float output
} pulse

Only sample frequency is mandatory. All variables of type float, except for sample frequency, can be any other type, as long as it matches the template parameter T.

When either override or output is omitted, names may become ambiguous. In that case, provide the ids of the fields that are in the store, as template parameters to objects():

field	id
sample frequency	`s`
amplitude	`A`
frequency	`f`
phase	`p`
duty cycle	`d`
enable	`e`
override	`F`
output	`O`

Then, instantiate the controller like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto pulse_o = stored::PulseWave<stored::YourStore>::objects("/pulse/");

// Instantiate the generator, tailored to the available fields in the store.
stored::PulseWave<stored::YourStore, pulse_o.flags()> pulse{pulse_o, yourStore};

Public Types

using Bound = typename PulseWaveObjects<Container, type>::template Bound<flags>

using type = T 

Public Functions

constexpr PulseWave() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr PulseWave(PulseWaveObjects<Container, type> const &o, Container &container): Initialize the pulse wave, given a list of objects and a container.

inline type amplitude() const noexcept: Return the amplitude value, or 1 when not available.

inline decltype(auto) amplitudeObject() const noexcept: Return the amplitude object.

inline decltype(auto) amplitudeObject() noexcept: Return the amplitude object.

inline void disable() noexcept

Disable the pulse wave.

Ignored when the enable object is not available.

inline type dutyCycle() const noexcept: Return the duty cycle value, or 0.5 when not available.

inline decltype(auto) dutyCycleObject() const noexcept: Return the duty cycle object.

inline decltype(auto) dutyCycleObject() noexcept: Return the duty cycle object.

inline void enable(bool value = true) noexcept

Enable (or disable) the pulse wave.

Ignored when the enable object is not available.

inline bool enabled() const noexcept: Return the enable value, or true when not available.

inline decltype(auto) enableObject() const noexcept: Return the enable object.

inline decltype(auto) enableObject() noexcept: Return the enable object.

inline type frequency() const noexcept: Return the frequency value, or 1 when not specified.

inline decltype(auto) frequencyObject() const noexcept: Return the frequency object.

inline decltype(auto) frequencyObject() noexcept: Return the frequency object.

inline bool isHealthy() const noexcept

Check numerical stability.

This function checks if for every control interval (1 / sampleFrequency()), the output is actually updated. Especially the period and phase values are checked if they are not too big.

You may want to check (or assert on) this function once in a while, like once per second or after every run, to detect a stuck controller within reasonable time for your application.

inline type operator()() noexcept: Compute the pulse wave output.

inline type output() const noexcept: Return the output value, or 0 when not available.

inline decltype(auto) outputObject() const noexcept: Return the output object.

inline decltype(auto) outputObject() noexcept: Return the output object.

inline type override_() const noexcept: Return the override value, or NaN when not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

inline type phase() const noexcept: Return the phase value, or 0 when not available.

inline decltype(auto) phaseObject() const noexcept: Return the phase object.

inline decltype(auto) phaseObject() noexcept: Return the phase object.

inline float sampleFrequency() const noexcept: Return the sample frequency.

inline decltype(auto) sampleFrequencyObject() const noexcept: Return the sample frequency object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

stored::Ramp

template<typename Container, unsigned long long flags = 0, typename T = float> class Ramp

Ramping setpoints, based on store variables.

This is a quadratic path planner, that creates a smooth path from the current output towards the provided input. The speed and acceleration can be limited.

To use this class, add a scope to your store, like:

{
    (float) sample frequency (Hz)
    float input
    float=inf speed limit
    float=inf acceleration limit
    bool reset
    bool=true enable
    float=nan override
    float output
} ramp

Only sample frequency is mandatory. All variables of type float, except for sample frequency, can be any other type, as long as it matches the template parameter T.

Then, instantiate the controller like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto ramp_o = stored::Ramp<stored::YourStore>::objects("/ramp/");

// Instantiate the generator, tailored to the available fields in the store.
stored::Ramp<stored::YourStore, ramp_o.flags()> ramp{ramp_o, yourStore};

The parameters can be changed while running (when reset is set to true). The change will be applied smoothly to the path.

Public Types

using Bound = typename RampObjects<Container, type>::template Bound<flags>

using type = T 

using type_ = long

Public Functions

constexpr Ramp() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr Ramp(RampObjects<Container, type> const &o, Container &container): Initialize the ramp, given a list of objects and a container.

inline type accelerationLimit() const noexcept: Return the acceleration limit value, or inf when not available.

inline decltype(auto) accelerationLimitObject() const noexcept: Return the acceleration limit object.

inline decltype(auto) accelerationLimitObject() noexcept: Return the acceleration limit object.

inline void disable() noexcept

Disable the pulse wave.

Ignored when the enable object is not available.

inline void enable(bool value = true) noexcept

Enable (or disable) the ramp.

Ignored when the enable object is not available.

inline bool enabled() const noexcept: Return the enable value, or true when not available.

inline decltype(auto) enableObject() const noexcept: Return the enable object.

inline decltype(auto) enableObject() noexcept: Return the enable object.

inline type input() const noexcept: Return the input value, or 0 when not available.

inline decltype(auto) inputObject() const noexcept: Return the input object.

inline decltype(auto) inputObject() noexcept: Return the input object.

inline bool isHealthy() const noexcept

Check numerical stability.

The Ramp is considered healthy when the configured acceleration and speed values are within the floating point precision.

You may want to check (or assert on) this function once in a while, like once per second or after every run, to detect a stuck ramp within reasonable time for your application.

inline type operator()() noexcept: Compute the next ramp output, given the input in the store.

inline type operator()(type input) noexcept: Compute the next ramp output, given an input.

inline type output() const noexcept: Return the output value, or 0 when not available.

inline decltype(auto) outputObject() const noexcept: Return the output object.

inline decltype(auto) outputObject() noexcept: Return the output object.

inline type override_() const noexcept: Return the override value, or NaN when not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

inline bool reset() const noexcept: Return the reset value, or false when not available.

inline decltype(auto) resetObject() const noexcept: Return the reset object.

inline decltype(auto) resetObject() noexcept: Return the reset object.

inline float sampleFrequency() const noexcept: Return the sample frequency.

inline decltype(auto) sampleFrequencyObject() const noexcept: Return the sample frequency object.

inline type speedLimit() const noexcept: Return the speed limit value, or inf when not available.

inline decltype(auto) speedLimitObject() const noexcept: Return the speed limit object.

inline decltype(auto) speedLimitObject() noexcept: Return the speed limit object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.

stored::Sine

template<typename Container, unsigned long long flags = 0, typename T = float> class Sine

Sine wave generator, based on store variables.

To use this class, add a scope to your store, like:

{
    (float) sample frequency (Hz)
    float=1 amplitude
    float=0.159 frequency (Hz)
    float=0 phase (rad)
    float=0 offset
    bool=true enable
    float=nan override
    float output
} sine

Only sample frequency is mandatory. All variables of type float, except for sample frequency, can be any other type, as long as it matches the template parameter T.

When either override or output is omitted, names may become ambiguous. In that case, provide the ids of the fields that are in the store, as template parameters to objects():

field	id
sample frequency	`s`
amplitude	`A`
frequency	`f`
phase	`p`
offset	`o`
enable	`e`
override	`F`
output	`O`

Then, instantiate the sine wave generator like this:

// Construct a compile-time object, which resolves all fields in your store.
constexpr auto sine_o = stored::Sine<stored::YourStore>::objects("/sine/");

// Instantiate the generator, tailored to the available fields in the store.
stored::Sine<stored::YourStore, sine_o.flags()> sine{sine_o, yourStore};

When the parameters of the sine wave are changed while running, they are applied immediately, without a smooth transition.

Public Types

using Bound = typename SineObjects<Container, type>::template Bound<flags>

using type = T 

Public Functions

constexpr Sine() noexcept = default

Default ctor.

Use this when initialization is postponed. You can assign another instance later on.

inline constexpr Sine(SineObjects<Container, type> const &o, Container &container): Initialize the sine, given a list of objects and a container.

inline type amplitude() const noexcept: Return the amplitude value, or 1 when not available.

inline decltype(auto) amplitudeObject() const noexcept: Return the amplitude object.

inline decltype(auto) amplitudeObject() noexcept: Return the amplitude object.

inline void disable() noexcept

Disable the sine wave.

Ignored when the enable object is not available.

inline void enable(bool value = true) noexcept

Enable (or disable) the sine wave.

Ignored when the enable object is not available.

inline bool enabled() const noexcept: Return the enable value, or true when not available.

inline decltype(auto) enableObject() const noexcept: Return the enable object.

inline decltype(auto) enableObject() noexcept: Return the enable object.

inline type frequency() const noexcept: Return the frequency value, or 1/2pi when not specified.

inline decltype(auto) frequencyObject() const noexcept: Return the frequency object.

inline decltype(auto) frequencyObject() noexcept: Return the frequency object.

inline bool isHealthy() const noexcept

Check numerical stability.

This function checks if for every control interval (1 / sampleFrequency()), the output is actually updated. Especially the period and phase values are checked if they are not too big.

You may want to check (or assert on) this function once in a while, like once per second or after every run, to detect a stuck controller within reasonable time for your application.

inline type offset() const noexcept: Return the offset value, or 0 when not available.

inline decltype(auto) offsetObject() const noexcept: Return the offset object.

inline decltype(auto) offsetObject() noexcept: Return the offset object.

inline type operator()() noexcept: Compute the sine output.

inline type output() const noexcept: Return the output value, or 0 when not available.

inline decltype(auto) outputObject() const noexcept: Return the output object.

inline decltype(auto) outputObject() noexcept: Return the output object.

inline type override_() const noexcept: Return the override value, or NaN when not available.

inline decltype(auto) overrideObject() const noexcept: Return the override object.

inline decltype(auto) overrideObject() noexcept: Return the override object.

inline type phase() const noexcept: Return the phase value, or 0 when not available.

inline decltype(auto) phaseObject() const noexcept: Return the phase object.

inline decltype(auto) phaseObject() noexcept: Return the phase object.

inline float sampleFrequency() const noexcept: Return the sample frequency.

inline decltype(auto) sampleFrequencyObject() const noexcept: Return the sample frequency object.

Public Static Functions

template<char... OnlyId, size_t N> static inline constexpr auto objects(char const (&prefix)[N]) noexcept: Create the list of objects in the store, used to compute the flags parameter.