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update keybrd_4c_split_keyboard_with_IOE.ino

tags/v0.6.0
wolfv6 7 years ago
parent
218a1ce284
commit
b5b24111e7
5 changed files with 30 additions and 42 deletions
Split View Show Diff Stats
  1. 7
    9
      src/PortMCP23S17.cpp
  2. 6
    6
      src/PortMCP23S17.h
  3. 13
    24
      tutorials/keybrd_4c_split_keyboard_with_IOE/keybrd_4c_split_keyboard_with_IOE.ino
  4. 2
    2
      tutorials/keybrd_5b_LED_on_IOE/keybrd_5b_LED_on_IOE.ino
  5. 2
    1
      tutorials/tutorial_4c_split_keyboard_with_IOE.md

+ 7
- 9
src/PortMCP23S17.cpp View File

@@ -1,36 +1,34 @@
#include "PortMCP23S17.h"

/* transfer() writes data to registerAddr, reads portSate from registerAddr, and returns portState.

MCP23S17 SPI interface is 10 MHz max.
The electrical limitation to bus speed is bus capacitance and the length of the wires involved.
Longer wires require lower clock speeds.
*/
uint8_t PortMCP23S17::transfer(const uint8_t command, const uint8_t registerAddr,
const uint8_t data)
{
uint8_t portState; //bit pattern

SPI.beginTransaction( SPISettings(5000000, MSBFIRST, SPI_MODE0) ); //control SPI bus, 5 MHz
digitalWrite(SS, LOW); //enable Slave Select
SPI.transfer(command); //write or read command
SPI.transfer(registerAddr); //register address to write data to
portState = SPI.transfer(data); //write data, read portState
digitalWrite(SS, HIGH); //disable Slave Select
SPI.endTransaction();

return portState;
}

/* begin() is called from Scanner_IOE::begin().
Initiates SPI bus and configures I/O pins for read and write.

MCP23S17 SPI interface is 10 MHz max.
The electrical limitation to bus speed is bus capacitance and the length of the wires involved.
Longer wires require lower clock speeds.
/* begin() is called from Scanner_IOE::begin(). Initiates SPI bus.
*/
void PortMCP23S17::beginProtocol()
{
pinMode(SS, OUTPUT); //configure controller's Slave Select pin to output
digitalWrite(SS, HIGH); //disable Slave Select
SPI.begin();
SPI.beginTransaction( SPISettings(5000000, MSBFIRST, SPI_MODE0) ); //control SPI bus, 5 MHz
//SPI.endTransaction() not called to release SPI bus because keyboard only has one SPI device
//if two IOEs are used, move beginTransaction() endTransaction() to write() read() functions
}

/* begin() is called from Scanner_IOE::begin().

+ 6
- 6
src/PortMCP23S17.h View File

@@ -6,8 +6,8 @@
#include <PortInterface.h>

/*
readPins are connected to matrix col
write pin is connected to matrix Row (strobe pin) or LED.
write pins are connected to matrix Row (strobe pin) or LED.
readPins are connected to matrix column to read which keys are pressed.

Slave Select is hardcoded to Arduino Pin 10.
Arduino Pin 10 avoids the speed penalty of digitalWrite.
@@ -20,9 +20,9 @@ MCP23S17 datasheet identifies ports by letters, while class PortMCP23S17 uses po
readPins parameter configures port's pins.

Example instantiation:
const uint8_t Port_MCP23S17::DEVICE_ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins grounded
Port_MCP23S17 portB(1, 0); //all pins are set to output for strobes and LEDs
Port_MCP23S17 portA(0, 1<<0 | 1<<1 ); //1 pins are set to input for reading,
const uint8_t IOE_ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded
Port_MCP23S17 portB(IOE_ADDR, 1, 0); //all pins are set to output for strobes and LEDs
Port_MCP23S17 portA(IOE_ADDR, 0, 1<<0 | 1<<1 ); //first two pins are set to input for reading,
//remaining pins can be used for LEDs

Diode orientation
@@ -39,7 +39,7 @@ class PortMCP23S17 : public PortInterface
const uint8_t deviceAddr;
const uint8_t portNum; //port identification number
uint8_t outputVal; //bit pattern for strobe and LEDs
const uint8_t readPins; //bits, IODIR 0=output, 1=input
const uint8_t readPins; //bit pattern, IODIR 0=output, 1=input
uint8_t transfer(const uint8_t command, const uint8_t registerAddr, const uint8_t data);
public:
PortMCP23S17(const uint8_t deviceAddr, const uint8_t portNum, const uint8_t readPins)

+ 13
- 24
tutorials/keybrd_4c_split_keyboard_with_IOE/keybrd_4c_split_keyboard_with_IOE.ino View File

@@ -21,9 +21,7 @@ This layout table shows left and right matrices:
#include <Scanner_uC.h>

//right matrix
#include <PortIOE.h>
#include <PortWrite_MCP23S17.h>
#include <PortRead_MCP23S17.h>
#include <PortMCP23S17.h>
#include <Scanner_IOE.h>

// ============ SPEED CONFIGURATION ============
@@ -33,37 +31,28 @@ ScanDelay scanDelay(9000);
Left matrix rows work the same as the ones in keybrd_2_single-layer.ino
*/
uint8_t readPins[] = {14, 15};
const uint8_t READPIN_COUNT = sizeof(readPins)/sizeof(*readPins);
const uint8_t readPinCount = sizeof(readPins)/sizeof(*readPins);

Scanner_uC scanner_L(LOW, readPins, READPIN_COUNT);
Scanner_uC scanner_L(LOW, readPins, readPinCount);

/* =============== RIGHT SCANNER ===============
The right matrix is scanned by an I/O expander.

The I/O expander device address is configured by hardware pins.
DEVICE_ADDR is a static variable of class PortIOE.
The MCP23S17 address is set by grounding or powering pins.
*/
const uint8_t PortIOE::DEVICE_ADDR = 0x20; //MCP23S17 address with all 3 ADDR pins are grounded
const uint8_t IOE_ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded

/*
port_B stobes the row while port_A reads the colums.

port_A is assigned port identification number 0.
port_A is assigned to portRead, which reads port_A pins 0 and 1.
Normally all strobe pins are on one port, and all the read pins are on the other port.
In this example, portB stobes the row while portA reads the colums.
PortMCP23S17 constructor parameters are: deviceAddr, portNum, readPins
readPins is a bit pattern, where 0=output, 1=input.
In portA, the first two pins are set to input for reading.
"<<" (bit shift left) and "|" (OR) are bitwise operators.
Pin numbers to be read are to the right of "1<<" and delimited by "|".
*/
PortIOE port_A(0);
PortRead_MCP23S17 portRead(port_A, 1<<0 | 1<<1 );

/*
port_B is assigned port identification number 1.
port_B is assigned to portWrite.
*/
PortIOE port_B(1);
PortWrite_MCP23S17 portWrite(port_B);

Scanner_IOE scanner_R(LOW, portWrite, portRead);
PortMCP23S17 portA(IOE_ADDR, 0, 1<<0 | 1<<1 );
PortMCP23S17 portB(IOE_ADDR, 1, 0);
Scanner_IOE scanner_R(LOW, portB, portA);

// =================== CODES ===================
Code_Sc s_a(KEY_A);

+ 2
- 2
tutorials/keybrd_5b_LED_on_IOE/keybrd_5b_LED_on_IOE.ino View File

@@ -34,7 +34,7 @@ This layout table shows left and right matrices:
// ============ SPEED CONFIGURATION ============
ScanDelay scanDelay(9000);

// ================ LEFT ===============
// ================= LEFT PINS =================
// ---------------- LEFT SCANNER ---------------
uint8_t readPins[] = {14, 15};
const uint8_t readPinCount = sizeof(readPins)/sizeof(*readPins);
@@ -44,7 +44,7 @@ Scanner_uC scanner_L(LOW, readPins, readPinCount);
// ----------------- LEFT LEDs -----------------
LED_uC LED_CapsLck(21);

// =============== RIGHT ===============
// ================ RIGHT PINS =================
// --------------- RIGHT SCANNER ---------------
const uint8_t IOE_ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded
PortMCP23S17 portA(IOE_ADDR, 0, 1<<0 | 1<<1 ); //for read and LED

+ 2
- 1
tutorials/tutorial_4c_split_keyboard_with_IOE.md View File

@@ -35,7 +35,8 @@ The MCP23S17 with all address pins grounded has an device address of 0x20.
The MCP23S17's /RESET pin is connected to VDD.

The MCP23S17 I/O expander has two ports. Each port has eight pins.
Port B is connected to the matrix's rows. Port A is connected to the matrix's columns.
Port B is connected to the matrix's rows.
Port A is connected to the matrix's columns.

Building a split keyboard with I/O Expander
-------------------------------------------