keybrd/src/RowScanner_SPIShiftRegisters.h

#ifndef ROWSCANNER_SPI_SHIFTREGISTERS_H
#define ROWSCANNER_SPI_SHIFTREGISTERS_H
#include <Arduino.h>
#include <inttypes.h>
#include <SPI.h>
#include <RowScannerInterface.h>
#include <RowPort.h>
#include <ColPort.h>

/* RowScanner_SPIShiftRegisters reads all shift registers in a daisy chain.
The maximum keys per row is 31, because Arduino's largest type is 32 bits and rowEnd consumes the last bit.
//todo delete: Assumes only one row of shift registers is connected (no Slave Select).
*/
class RowScanner_SPIShiftRegisters : public RowScannerInterface
{
    private:
        const uint8_t SS;                       //pin on master that selects slave
        const uint8_t BYTE_COUNT;               //number of bytes to read from shift registers
        const uint8_t KEY_COUNT;                //number of keys in row
    public:
        RowScanner_SPIShiftRegisters(const uint8_t SS, uint8_t BYTE_COUNT, uint8_t KEY_COUNT)
            : SS(SS), BYTE_COUNT(BYTE_COUNT), KEY_COUNT(KEY_COUNT) {}
        virtual read_pins_t scan(read_pins_mask_t& rowEnd);
        void begin();
};
#endif