52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
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#include "Scanner_ShiftRegsPISOMultiRow.h"
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/* constructor
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*/
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Scanner_ShiftRegsPISOMultiRow::Scanner_ShiftRegsPISOMultiRow(const bool strobeOn,
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const uint8_t slaveSelect, const uint8_t byte_count)
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: strobeOn(strobeOn), strobeOff(!strobeOn),
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slaveSelect(slaveSelect), byte_count(byte_count)
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{
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pinMode(slaveSelect, OUTPUT);
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}
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/* init() is called once for each row from Row constructor.
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Configures controller to communicate with shift register matrix.
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*/
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void Scanner_ShiftRegsPISOMultiRow::init(const uint8_t strobePin)
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{
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pinMode(strobePin, OUTPUT);
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}
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/* begin() should be called once from sketch setup().
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Initializes shift register's shift/load pin.
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*/
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void Scanner_ShiftRegsPISOMultiRow::begin()
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{
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digitalWrite(slaveSelect, HIGH);
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}
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/* scan() strobes the row's strobePin and returns state of the shift register's input pins.
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strobePin is Arduino pin number connected to this row.
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Bit patterns are 1 bit per key.
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*/
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read_pins_t Scanner_ShiftRegsPISOMultiRow::scan(const uint8_t strobePin)
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{
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read_pins_t readState = 0; //bits, 1 means key is pressed, 0 means released
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//strobe row on
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digitalWrite(strobePin, strobeOn);
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delayMicroseconds(3); //time to stablize voltage
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//read all the column pins
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digitalWrite(slaveSelect, LOW); //load parallel inputs to the register
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digitalWrite(slaveSelect, HIGH); //shift the data toward a serial output
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SPI.transfer(&readState, byte_count);
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//strobe row off
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digitalWrite(strobePin, strobeOff);
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return readState;
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}
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