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keybrd/src/Port_MCP23018.h

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#ifndef PORT_MCP23018_H
#define PORT_MCP23018_H
#include <Arduino.h>
#include <inttypes.h>
#include <Wire.h>
#include <PortInterface.h>
/*
write pins are connected to matrix Row (strobe pin) or LED.
readPins are connected to matrix column to read which keys are pressed.
MCP23018 has open-drain outputs (open-drain can only sink current). If LEDs are used, connect:
LED anodes (the longer lead) to power
LED cathodes (the shorter lead) to GPIO pin
Instantiation
------------
Example instantiation:
const uint8_t IOE_ADDR = 0x20; //MCP23018 address pin grounded
Port_MCP23018 portB(IOE_ADDR, 1, 0); //all pins are set to output for strobes and LEDs
Port_MCP23018 portA(IOE_ADDR, 0, 1<<0 | 1<<1 ); //pin 0 and pin 1 are set to input for reading,
//remaining pins can be used for LEDs
Diode orientation
----------------
Diode orientation is explained in keybrd_library_user_guide.md > Diode orientation
MCP23018 data sheet
----------------
http://ww1.microchip.com/downloads/en/DeviceDoc/22103a.pdf
*/
class Port_MCP23018 : public PortInterface
{
private:
const uint8_t deviceAddr;
const uint8_t portNum; //port identification number, 0=A, 1=B
uint8_t outputVal; //bit pattern for strobe and LEDs
const uint8_t readPins; //bit pattern, IODIR 0=output, 1=input
public:
Port_MCP23018(const uint8_t deviceAddr, const uint8_t portNum, const uint8_t readPins)
: deviceAddr(deviceAddr), portNum(portNum), outputVal(0), readPins(readPins) {}
void beginProtocol();
2016-11-16 01:41:05 +00:00
void begin(const uint8_t activeState);
virtual void setLow(const uint8_t pin);
virtual void setHigh(const uint8_t pin);
virtual uint8_t read();
};
#endif