@@ -186,6 +186,8 @@ Most derived-class names start with the base class name followed by "_" and a na | |||
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. | |||
Interface class names end with "Interface". | |||
Layer-class naming conventions | |||
------------------------------ | |||
Layer classes are explained in [tutorial_3a_multi-layer_keyboard.md](../tutorials/tutorial_3a_multi-layer_keyboard.md). |
@@ -4,20 +4,42 @@ | |||
PortRead_MCP23S17::begin() is not needed because port direction is already configured to input by default. | |||
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 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; | |||
} |
@@ -7,11 +7,10 @@ | |||
#include "PortIOE.h" | |||
/* 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) | |||
0=configure as output (for LED or not connected to a column) | |||
@@ -22,18 +21,17 @@ Example instantiation for column port 1, with pins 2 and 3 connected to columns: | |||
PortIOE port1(1, 0); | |||
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 | |||
{ | |||
private: | |||
PortIOE& port; | |||
const uint8_t pullUp; //bitwise, 1 means internal pull-up resistor enabled | |||
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(); | |||
}; | |||
#endif |
@@ -1,32 +1,31 @@ | |||
#include "PortWrite_MCP23S17.h" | |||
/* writePort() sets registerAddr to 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. | |||
SPI.endTransaction() is not called because keyboard only has one SPI device, so no need to release the SPI bus | |||
*/ | |||
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.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. | |||
} | |||
/* |
@@ -16,7 +16,7 @@ To write a new Port class: | |||
Write very simple read and write examples for your I/O expander. | |||
Simple SPI I/O expander examples: | |||
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/ | |||
Simple I2C I/O expander examples: | |||
todo link, pictures |
@@ -9,24 +9,22 @@ http://arduino.stackexchange.com/questions/28792/reading-an-mcp23s17-i-o-expande | |||
*/ | |||
#include "PortIOE.h" | |||
#include "PortRead_MCP23S17.h" | |||
#include "PortWrite_MCP23S17.h" | |||
const uint8_t PortIOE::ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded | |||
PortIOE portB(1, 0); | |||
PortRead_MCP23S17 portBRead(portB); | |||
PortWrite_MCP23S17 portBWrite(portB); //PortBWrite needed for begin() | |||
PortRead_MCP23S17 portBRead(portB, ~0); | |||
void setup() | |||
{ | |||
uint8_t portBState; //bit wise | |||
delay(6000); | |||
portBWrite.begin(); | |||
portBRead.begin(); | |||
portBState = portBRead.read(); | |||
Keyboard.print("portBState = "); | |||
Keyboard.println(portBState, BIN); //should print 10101010 | |||
Keyboard.println(portBState, BIN); //prints 10101010 | |||
} | |||
void loop() { } |