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- #ifndef PORT_MCP23018_H
- #define PORT_MCP23018_H
- #include "Port_MCP23017.h"
-
- /* Port_MCP23018
- write pins are connected to matrix Row (strobe pin) or LED.
- readPins are connected to matrix column to read which keys are pressed.
-
- Port_MCP23018 can only be active low (Scanner_IOE::activeState = LOW).
- Open-drain active high would not work because pull down resistors have no effect on sink.
- https://en.wikipedia.org/wiki/Open_collector
-
- Use LED_PortOpenDrain class for indicator LEDs.
-
- 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
- */
-
- class Port_MCP23018 : public Port_MCP23017
- {
- public:
- Port_MCP23018(const uint8_t deviceAddr, const uint8_t portNum, const uint8_t readPins)
- : Port_MCP23017(deviceAddr, portNum, readPins) {}
- };
- #endif
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