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- #include "Scanner_ShiftRegsRead.h"
-
- /* constructor
- Parameter activeState is not used.
- */
- Scanner_ShiftRegsRead::Scanner_ShiftRegsRead(const bool activeState,
- const uint8_t slaveSelect, const uint8_t byte_count)
- : slaveSelect(slaveSelect), byte_count(byte_count)
- {
- pinMode(slaveSelect, OUTPUT);
- }
-
- /* init() is called once for each row from Row constructor.
- */
- void Scanner_ShiftRegsRead::init(const uint8_t strobePin)
- {
- //empty function
- }
-
- /* begin() should be called once from sketch setup().
- Initializes shift register's shift/load pin.
- */
- void Scanner_ShiftRegsRead::begin()
- {
- SPI.begin();
- digitalWrite(slaveSelect, HIGH);
- }
-
- /* scan() returns state of the shift register's input pins.
- Parameter strobePin is not used.
- No strobe pin is needed, the shift register is wired so the strobe is effectivley always "on".
- Bit patterns are 1 bit per key.
- */
- read_pins_t Scanner_ShiftRegsRead::scan(const uint8_t strobePin)
- {
- read_pins_t readState = 0; //bits, 1 means key is pressed, 0 means released
-
- //read all the column pins
- digitalWrite(slaveSelect, HIGH); //shift the data toward a serial output
- SPI.transfer(&readState, byte_count);
- digitalWrite(slaveSelect, LOW); //load parallel inputs to the register
-
- return readState;
- }
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