49 rader
1.7 KiB
C++
49 rader
1.7 KiB
C++
#ifndef PORTREAD_MCP23S17_H
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#define PORTREAD_MCP23S17_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 <PortReadInterface.h>
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#include "PortMCP23S17.h"
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#include "PortIOE.h"
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#include "Scanner_IOE.h"
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/* One MCP23S17 I/O expander port connected to matrix columns.
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This class has Slave Select 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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readPins parameter is port's bit pattern pin configuration
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1=configure as input (for read pins connected to column)
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0=configure as output (for LED or not connected to a column)
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readPins are read from pin 0 on up.
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Example instantiation with port-A pins 0 and 1 connected to Scanner_IOE columns:
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const uint8_t PortIOE::DEVICE_ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded
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PortIOE port_A(0);
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PortRead_MCP23S17 portRead_A(port_A, 1<<0 | 1<<1 );
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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 PortRead_MCP23S17 : public PortReadInterface, public PortMCP23S17
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{
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private:
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PortIOE& port;
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uint8_t pullUp; //bits, 1 means internal pull-up resistor enabled
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const uint8_t readPins; //bits, 1 means internal pull-up resistor enabled
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public:
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PortRead_MCP23S17(PortIOE& port, const uint8_t readPins)
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: port(port), readPins(readPins) {}
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void begin(const uint8_t strobeOn);
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virtual uint8_t read();
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};
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#endif
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