This convention leads to class names that convey information about the classes inheritance. | This convention leads to class names that convey information about the classes inheritance. | ||||
Underscore delineates base class name and sub-class name. Capital letters delineate words. | Underscore delineates base class name and sub-class name. Capital letters delineate words. | ||||
Interface class names end with "Interface". | |||||
Layer-class naming conventions | Layer-class naming conventions | ||||
------------------------------ | ------------------------------ | ||||
Layer classes are explained in [tutorial_3a_multi-layer_keyboard.md](../tutorials/tutorial_3a_multi-layer_keyboard.md). | Layer classes are explained in [tutorial_3a_multi-layer_keyboard.md](../tutorials/tutorial_3a_multi-layer_keyboard.md). |
PortRead_MCP23S17::begin() is not needed because port direction is already configured to input by default. | PortRead_MCP23S17::begin() is not needed because port direction is already configured to input by default. | ||||
SPI bus is configured in PortWrite_MCP23S17::begin(). | SPI bus is configured in PortWrite_MCP23S17::begin(). | ||||
*/ | */ | ||||
void PortRead_MCP23S17::begin() | |||||
{ | |||||
pinMode(SS, OUTPUT); //configure controller's Slave Select pin to output | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
SPI.begin(); | |||||
SPI.beginTransaction(SPISettings (SPI_CLOCK_DIV8, MSBFIRST, SPI_MODE0)); //control SPI bus todo is slow clock needed? | |||||
digitalWrite(SS, LOW); //enable Slave Select | |||||
SPI.transfer(port.ADDR << 1); //write command | |||||
SPI.transfer(port.num); //configure IODIR | |||||
SPI.transfer(pullUp); //0=output (for LED), 1=input (for read) | |||||
digitalWrite(SS, LOW); //enable Slave Select | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
SPI.transfer(port.ADDR << 1); //write command | |||||
SPI.transfer(port.num + 0x0C); //configure GPPU | |||||
SPI.transfer(pullUp); //0=pull-up disabled (for LED), 1=pull-up enabled (for read) | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
//SPI.endTransaction() is not called to release the SPI bus | |||||
// because keyboard only has one SPI device. | |||||
} | |||||
/* | /* | ||||
returns port value | |||||
read() returns portState. | |||||
*/ | */ | ||||
uint8_t PortRead_MCP23S17::read() | uint8_t PortRead_MCP23S17::read() | ||||
{ | { | ||||
uint8_t portState; //bit wise | |||||
//slower clock | |||||
digitalWrite(SS, LOW); //enable Slave Select | |||||
SPI.transfer(port.ADDR << 1 | 1); //read command | |||||
SPI.transfer(port.num + 0x12); //register address to read data from | |||||
portState = SPI.transfer(0); //save the data (0 is dummy data to send) | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
uint8_t portState; //bit wise | |||||
digitalWrite(SS, LOW); //enable Slave Select | |||||
SPI.transfer(port.ADDR << 1 | 1); //read command | |||||
SPI.transfer(port.num + 0x12); //GPIO register address to read data from | |||||
portState = SPI.transfer(0); //save the data (0 is dummy data to send) | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
return portState; | return portState; | ||||
} | } |
#include "PortIOE.h" | #include "PortIOE.h" | ||||
/* One MCP23S17 I/O expander port connected to matrix columns. | /* One MCP23S17 I/O expander port connected to matrix columns. | ||||
MCP23S17 does not have internal pull-up resistors (PCA9535E does). | |||||
Instantiation | |||||
Instantiation todo | |||||
------------ | ------------ | ||||
readPins parameter is port's bitwise pin configuration | |||||
pullUp parameter is port's bitwise pin configuration | |||||
1=configure as input (for pins connected to column) | 1=configure as input (for pins connected to column) | ||||
0=configure as output (for LED or not connected to a column) | 0=configure as output (for LED or not connected to a column) | ||||
PortIOE port1(1, 0); | PortIOE port1(1, 0); | ||||
PortRead_MCP23S17 colPort1(port1, 2<<0 | 1<<3 ); | PortRead_MCP23S17 colPort1(port1, 2<<0 | 1<<3 ); | ||||
readPins are read from pin 0 on up. | |||||
pullUp are read from pin 0 on up. | |||||
*/ | */ | ||||
class PortRead_MCP23S17 : public PortRead | class PortRead_MCP23S17 : public PortRead | ||||
{ | { | ||||
private: | private: | ||||
PortIOE& port; | PortIOE& port; | ||||
const uint8_t pullUp; //bitwise, 1 means internal pull-up resistor enabled | |||||
public: | public: | ||||
/* | |||||
*/ | |||||
//The constructor initialization list is in .cpp | |||||
PortRead_MCP23S17(PortIOE& port) : port(port) {} | |||||
PortRead_MCP23S17(PortIOE& port, const uint8_t pullUp) : port(port), pullUp(pullUp) {} | |||||
void begin(); | |||||
virtual uint8_t read(); | virtual uint8_t read(); | ||||
}; | }; | ||||
#endif | #endif |
#include "PortWrite_MCP23S17.h" | #include "PortWrite_MCP23S17.h" | ||||
/* writePort() sets registerAddr to data. | |||||
*/ | |||||
void PortWrite_MCP23S17::writePort(const uint8_t registerAddr, const uint8_t data) | void PortWrite_MCP23S17::writePort(const uint8_t registerAddr, const uint8_t data) | ||||
{ | { | ||||
//slower clock | |||||
//SPI.beginTransaction(SPISettings (SPI_CLOCK_DIV8, MSBFIRST, SPI_MODE0)); //control SPI bus todo move to begin() | |||||
digitalWrite(SS, LOW); //enable Slave Select | |||||
SPI.transfer(port.ADDR << 1); //write command | |||||
SPI.transfer(registerAddr); //register address to write data to | |||||
SPI.transfer(data); //data | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
//SPI.endTransaction(); //release the SPI bus | |||||
digitalWrite(SS, LOW); //enable Slave Select | |||||
SPI.transfer(port.ADDR << 1); //write command | |||||
SPI.transfer(registerAddr); //register address to write data to | |||||
SPI.transfer(data); //data | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
} | } | ||||
/* | |||||
If PortRead_MCP23S17 is instantiated on the same port, do NOT use PortWrite_MCP23S17::begin(). | |||||
Otherwise readPins could be overwritten. | |||||
/* begin() should be called once from sketch in setup(). | |||||
PortRead_MCP23S17 and PortWrite_MCP23S17 should be on seperate ports on the same MCP23S17. | |||||
Output pins can be used for strobe pins and LEDs. | Output pins can be used for strobe pins and LEDs. | ||||
SPI.endTransaction() is not called because keyboard only has one SPI device, so no need to release the SPI bus | |||||
*/ | */ | ||||
void PortWrite_MCP23S17::begin() | void PortWrite_MCP23S17::begin() | ||||
{ | { | ||||
pinMode(SS, OUTPUT); //configure controller's Slave Select pin to output | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
pinMode(SS, OUTPUT); //configure controller's Slave Select pin to output | |||||
digitalWrite(SS, HIGH); //disable Slave Select | |||||
SPI.begin(); | SPI.begin(); | ||||
SPI.beginTransaction(SPISettings (SPI_CLOCK_DIV8, MSBFIRST, SPI_MODE0)); //control SPI bus | |||||
SPI.beginTransaction(SPISettings (SPI_CLOCK_DIV8, MSBFIRST, SPI_MODE0)); //control SPI bus todo is slow clock needed? | |||||
writePort(port.num, 0); //configure port direction (port.num) to output (0) | |||||
writePort(port.num, 0); //configure port direction (port.num) to output (0) | |||||
//SPI.endTransaction() is not called to release the SPI bus | |||||
// because keyboard only has one SPI device. | |||||
} | } | ||||
/* | /* |
Write very simple read and write examples for your I/O expander. | Write very simple read and write examples for your I/O expander. | ||||
Simple SPI I/O expander examples: | Simple SPI I/O expander examples: | ||||
todo link, pictures | todo link, pictures | ||||
/home/wolfv/Documents/Arduino/demo/IOE_MCP23S17_read/ | |||||
/home/wolfv/Documents/Arduino/demo/IOE_MCP23S17_read/ todo internal pull-up resistors | |||||
/home/wolfv/Documents/Arduino/demo/IOE_MCP23S17_write/ | /home/wolfv/Documents/Arduino/demo/IOE_MCP23S17_write/ | ||||
Simple I2C I/O expander examples: | Simple I2C I/O expander examples: | ||||
todo link, pictures | todo link, pictures |
*/ | */ | ||||
#include "PortIOE.h" | #include "PortIOE.h" | ||||
#include "PortRead_MCP23S17.h" | #include "PortRead_MCP23S17.h" | ||||
#include "PortWrite_MCP23S17.h" | |||||
const uint8_t PortIOE::ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded | const uint8_t PortIOE::ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded | ||||
PortIOE portB(1, 0); | PortIOE portB(1, 0); | ||||
PortRead_MCP23S17 portBRead(portB); | |||||
PortWrite_MCP23S17 portBWrite(portB); //PortBWrite needed for begin() | |||||
PortRead_MCP23S17 portBRead(portB, ~0); | |||||
void setup() | void setup() | ||||
{ | { | ||||
uint8_t portBState; //bit wise | uint8_t portBState; //bit wise | ||||
delay(6000); | delay(6000); | ||||
portBWrite.begin(); | |||||
portBRead.begin(); | |||||
portBState = portBRead.read(); | portBState = portBRead.read(); | ||||
Keyboard.print("portBState = "); | Keyboard.print("portBState = "); | ||||
Keyboard.println(portBState, BIN); //should print 10101010 | |||||
Keyboard.println(portBState, BIN); //prints 10101010 | |||||
} | } | ||||
void loop() { } | void loop() { } |