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