53 lines
1.9 KiB
C++
53 lines
1.9 KiB
C++
#ifndef PORTMCP23S17_H
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#define PORTMCP23S17_H
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#include <Arduino.h>
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#include <inttypes.h>
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#include <SPI.h>
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#include <PortInterface.h>
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/*
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readPins are connected to matrix col
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write pin is connected to matrix Row (strobe pin) or LED.
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Slave Select is hardcoded to Arduino Pin 10.
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Arduino Pin 10 avoids the speed penalty of digitalWrite.
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Instantiation
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------------
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MCP23S17 datasheet identifies ports by letters, while class PortMCP23S17 uses portNum
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for port A, use portNum=0
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for port B, use portNum=1
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readPins parameter configures port's pins.
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Example instantiation:
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const uint8_t Port_MCP23S17::DEVICE_ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins grounded
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Port_MCP23S17 portB(1, 0); //all pins are set to output for strobes and LEDs
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Port_MCP23S17 portA(0, 1<<0 | 1<<1 ); //1 pins 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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MCP23S17 data sheet
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------------------
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http://www.onsemi.com/pub_link/Collateral/MCP23S17-D.PDF
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*/
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class PortMCP23S17 : 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
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uint8_t outputVal; //bit pattern for strobe and LEDs
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const uint8_t readPins; //bits, IODIR 0=output, 1=input
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uint8_t transfer(const uint8_t command, const uint8_t registerAddr, const uint8_t data);
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public:
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PortMCP23S17(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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