cs-midi/AH/Hardware/ButtonMatrix.hpp

95 lines
2.8 KiB
C++

/* ✔ */
#pragma once
#include <AH/Hardware/Hardware-Types.hpp>
BEGIN_AH_NAMESPACE
/**
* @brief A class that reads the states of a button matrix.
*
* @tparam NumRows
* The number of rows in the button matrix.
* @tparam NumCols
* The number of columns in the button matrix.
*
* @ingroup AH_HardwareUtils
*/
template <class Derived, uint8_t NumRows, uint8_t NumCols>
class ButtonMatrix {
public:
/**
* @brief Construct a new ButtonMatrix object.
*
* @param rowPins
* A list of pin numbers connected to the rows of the button
* matrix.
* **⚠** These pins will be driven LOW as outputs (Lo-Z).
* @param colPins
* A list of pin numbers connected to the columns of the button
* matrix.
* These pins will be used as inputs (Hi-Z), and the internal
* pull-up resistor will be enabled.
*/
ButtonMatrix(const PinList<NumRows> &rowPins,
const PinList<NumCols> &colPins);
/**
* @brief Initialize (enable internal pull-up resistors on column pins).
*/
void begin();
/**
* @brief Scan the matrix, read all button states, and call the
* onButtonChanged callback.
*/
void update();
/**
* Get the state of the button in the given column and row.
*
* @note No bounds checking is performed.
*/
bool getPrevState(uint8_t col, uint8_t row);
/// Configure the debounce time interval. Only one button can change in each
/// debounce interval. Time in milliseconds.
void setDebounceTime(unsigned long debounceTime) {
this->debounceTime = debounceTime;
}
/// Get the debounce time.
unsigned long getDebounceTime() const { return debounceTime; }
protected:
/**
* @brief The callback function that is called whenever a button changes
* state. Implement this in the derived class.
*
* @param row
* The row of the button that changed state.
* @param col
* The column of the button that changed state.
* @param state
* The new state of the button.
*/
void onButtonChanged(uint8_t row, uint8_t col, bool state) = delete;
private:
static inline uint8_t positionToBits(uint8_t col, uint8_t row);
static inline uint8_t bitsToIndex(uint8_t bits);
static inline uint8_t bitsToBitmask(uint8_t bits);
void setPrevState(uint8_t col, uint8_t row, bool state);
unsigned long debounceTime = BUTTON_DEBOUNCE_TIME;
unsigned long prevRefresh = 0;
uint8_t prevStates[(NumCols * NumRows + 7) / 8];
const PinList<NumRows> rowPins;
const PinList<NumCols> colPins;
};
END_AH_NAMESPACE
#include "ButtonMatrix.ipp" // Template implementations