#ifndef PORTREAD_MCP23S17_H
#define PORTREAD_MCP23S17_H
#include <Arduino.h>
#include <inttypes.h>
#include <SPI.h>
#include <PortRead.h>
#include "PortIOE.h"

/* One MCP23S17 I/O expander port connected to matrix columns.
MCP23S17 does not have internal pull-up resistors (PCA9535E does).

Instantiation
 ------------
readPins parameter is port's bitwise pin configuration
    1=configure as input (for pins connected to column)
    0=configure as output (for LED or not connected to a column)

Example instantiation for column port 0, with pins 2 and 3 connected to columns:
    PortIOE port0(0, 0);
    PortRead_MCP23S17 colPort0(port0, 2<<0 | 1<<3 );
Example instantiation for column port 1, with pins 2 and 3 connected to columns:
    PortIOE port1(1, 0);
    PortRead_MCP23S17 colPort1(port1, 2<<0 | 1<<3 );

readPins are read from pin 0 on up.

*/
class PortRead_MCP23S17 : public PortRead
{
    private:
        PortIOE& port;
    public:
/*
todo not all PortRead_ classes need a readPins
    move PortRead::readPins from PortRead to PortRead_PCA9655E
    remove PortRead(0) initialization from this constructor
*/
        //The constructor initialization list is in .cpp
        PortRead_MCP23S17(PortIOE& port) : PortRead(0), port(port) {}
        virtual uint8_t read();
};
#endif