Matrix Game Console

/*
Namespace: Display
Author: John Bradnam (jbrad2089@gmail.com)
Purpose: 8x8 Red/Green Matrix display routines
*/
#pragma once
#include <SPI.h>// SPI Library used to clock data out to the shift registers

namespace srn
{
  
#define LATCH_PIN 13   //PC3 can use any pin you want to latch the shift registers
#define BLANK_PIN 8    //PB1 same, can use any pin you want for this, just make sure you pull up via a 1k to 5V
#define DATA_PIN 14    //PA1 used by SPI, must be pin 11
#define CLOCK_PIN 16   //PA3 used by SPI, must be 13
#define ANODE_A 7      //PB2 74138 A Input
#define ANODE_B 6      //PB3 74138 B Input
#define ANODE_C 5      //PB4 74138 C Input

#define BLANK_PORT    PORTB
#define BLANK_BM      PIN1_bm
#define LATCH_PORT    PORTC
#define LATCH_BM      PIN3_bm

#define ROWS 8            //Number of rows of LEDs
#define LEDS_PER_ROW 16   //Number of leds on each row
#define BYTES_PER_ROW 2   //Number of bytes required to hold one bit per LED in each row

enum CMODE { C_BLACK, C_RED, C_GRN, C_ORG };

//Bit buffer for matrix
byte ledStates[ROWS][BYTES_PER_ROW];  //Store state of each LED (either off or on)
byte ledNext[ROWS][BYTES_PER_ROW];    //Double buffer for fast updates
int8_t activeRow = 0;                 //this increments through the anode levels

#define SCROLL_SPEED 30               //Speed at which text is scrolled
String scrollText;                    //Used to store scrolling text
volatile int8_t scrollDelay;          //Used to store scroll delay
volatile int8_t scrollCharPos;        //Current character position in text being scrolled
volatile int8_t scrollCharCol;        //Next column in character to display
volatile int8_t scrollOffScreen;      //Extra columns required to scroll last character off screen
volatile CMODE scrollColor;           //String color

//Font
#define SPACE 16
const uint8_t font5x7 [43][5] PROGMEM = {
  {0x3E, 0x51, 0x49, 0x45, 0x3E}, // 0 
  {0x00, 0x42, 0x7F, 0x40, 0x00}, // 1 
  {0x42, 0x61, 0x51, 0x49, 0x46}, // 2 
  {0x21, 0x41, 0x45, 0x4B, 0x31}, // 3 
  {0x18, 0x14, 0x12, 0x7F, 0x10}, // 4 
  {0x27, 0x45, 0x45, 0x45, 0x39}, // 5 
  {0x3C, 0x4A, 0x49, 0x49, 0x30}, // 6 
  {0x01, 0x71, 0x09, 0x05, 0x03}, // 7 
  {0x36, 0x49, 0x49, 0x49, 0x36}, // 8 
  {0x06, 0x49, 0x49, 0x29, 0x1E}, // 9 
  {0x00, 0x36, 0x36, 0x00, 0x00}, // : 
  {0x00, 0x56, 0x36, 0x00, 0x00}, // ; 
  {0x08, 0x14, 0x22, 0x41, 0x00}, // < 
  {0x14, 0x14, 0x14, 0x14, 0x14}, // = 
  {0x00, 0x41, 0x22, 0x14, 0x08}, // > 
  {0x02, 0x01, 0x51, 0x09, 0x06}, // ? 
  {0x00, 0x00, 0x00, 0x00, 0x00}, // Space 
  {0x7C, 0x12, 0x11, 0x12, 0x7C}, // A 
  {0x7F, 0x49, 0x49, 0x49, 0x36}, // B 
  {0x3E, 0x41, 0x41, 0x41, 0x22}, // C 
  {0x7F, 0x41, 0x41, 0x22, 0x1C}, // D 
  {0x7F, 0x49, 0x49, 0x49, 0x41}, // E 
  {0x7F, 0x09, 0x09, 0x09, 0x01}, // F 
  {0x3E, 0x41, 0x49, 0x49, 0x7A}, // G 
  {0x7F, 0x08, 0x08, 0x08, 0x7F}, // H 
  {0x00, 0x41, 0x7F, 0x41, 0x00}, // I 
  {0x20, 0x40, 0x41, 0x3F, 0x01}, // J 
  {0x7F, 0x08, 0x14, 0x22, 0x41}, // K 
  {0x7F, 0x40, 0x40, 0x40, 0x40}, // L 
  {0x7F, 0x02, 0x0C, 0x02, 0x7F}, // M 
  {0x7F, 0x04, 0x08, 0x10, 0x7F}, // N 
  {0x3E, 0x41, 0x41, 0x41, 0x3E}, // O 
  {0x7F, 0x09, 0x09, 0x09, 0x06}, // P 
  {0x3E, 0x41, 0x51, 0x21, 0x5E}, // Q 
  {0x7F, 0x09, 0x19, 0x29, 0x46}, // R 
  {0x46, 0x49, 0x49, 0x49, 0x31}, // S 
  {0x01, 0x01, 0x7F, 0x01, 0x01}, // T 
  {0x3F, 0x40, 0x40, 0x40, 0x3F}, // U 
  {0x1F, 0x20, 0x40, 0x20, 0x1F}, // V 
  {0x3F, 0x40, 0x38, 0x40, 0x3F}, // W 
  {0x63, 0x14, 0x08, 0x14, 0x63}, // X 
  {0x07, 0x08, 0x70, 0x08, 0x07}, // Y 
  {0x61, 0x51, 0x49, 0x45, 0x43}  // Z 
};

//-------------------------------------------------------------------------
//Forward references
void setup();
void refresh();
void drawString(String s, CMODE color);
void scrollTextLeft();
void drawCharacter(int8_t x, char ch, CMODE color);
void setPixel(int8_t r, int8_t c, CMODE color);
CMODE getPixel(int8_t r, int8_t c);
int8_t mapColumn(int8_t c, bool g);
int8_t mapColumnRed(int8_t c);
int8_t mapColumnGrn(int8_t c);
void setBitInArray(int8_t r, int8_t c, bool on);
bool getBitInArray(int8_t r, int8_t c);
void clearDisplay();

//-------------------------------------------------------------------------
//Initialise Hardware

void setup()
{
  SPI.setBitOrder(MSBFIRST);//Most Significant Bit First
  SPI.setDataMode(SPI_MODE0);// Mode 0 Rising edge of data, keep clock low
  SPI.setClockDivider(SPI_CLOCK_DIV2);//Run the data in at 16MHz/2 - 8MHz

  noInterrupts();// kill interrupts until everybody is set up
  activeRow = 0;

  //Set up display refresh timer
  //CLK_PER = 3.3MHz (303nS)
  TCB1.CCMP = 49152;   //Refresh value for display (67Hz)
  TCB1.INTCTRL = TCB_CAPT_bm;
  TCB1.CTRLA = TCB_ENABLE_bm;

  //finally set up the Outputs
  pinMode(LATCH_PIN, OUTPUT);//Latch
  pinMode(DATA_PIN, OUTPUT);//MOSI DATA
  pinMode(CLOCK_PIN, OUTPUT);//SPI Clock
  //Setup pins to 3 to 8 channel multiplexer
  pinMode(ANODE_A, OUTPUT);
  pinMode(ANODE_B, OUTPUT);
  pinMode(ANODE_C, OUTPUT);

  //pinMode(BLANK_PIN, OUTPUT);//Output Enable  important to do this last, so LEDs do not flash on boot up
  SPI.begin();//start up the SPI library
  interrupts();//let the show begin, this lets the multiplexing start
}

//-------------------------------------------------------------------------
//Timer B Interrupt handler interrupt each mS - output segments
ISR(TCB1_INT_vect)
{

  BLANK_PORT.OUTSET = BLANK_BM; //The first thing we do is turn all of the LEDs OFF, by writing a 1 to the blank pin
  
  //Turn on all columns
  for (int shift_out = 0; shift_out < BYTES_PER_ROW; shift_out++)
  {
    SPI.transfer(ledStates[activeRow][shift_out]);
  }

  //Enable row that we just outputed the column data for
  digitalWrite(ANODE_A, (activeRow & 0x01) ? LOW : HIGH);
  digitalWrite(ANODE_B, (activeRow & 0x02) ? LOW : HIGH);
  digitalWrite(ANODE_C, (activeRow & 0x04) ? LOW : HIGH);

  LATCH_PORT.OUTSET = LATCH_BM; //Latch pin HIGH
  LATCH_PORT.OUTCLR = LATCH_BM; //Latch pin LOW
  BLANK_PORT.OUTCLR = BLANK_BM; //Blank pin LOW to turn on the LEDs with the new data

  activeRow = (activeRow + 1) % ROWS;   //increment the active row
  
  BLANK_PORT.DIRSET = BLANK_BM; //Make BLANK pin an OUTPUT

  //Handle scrolling of text
  if (scrollDelay != 0)
  {
    scrollDelay--;
    if (scrollDelay == 0)
    {
      scrollDelay = SCROLL_SPEED;
      scrollTextLeft();
    }
  }

  //Clear interrupt flag
  TCB1.INTFLAGS |= TCB_CAPT_bm; //clear the interrupt flag(to reset TCB1.CNT)
}

//---------------------------------------------------------------
//Transfers the working buffer to the display buffer
void refresh()
{
  memcpy(ledStates, ledNext, ROWS * BYTES_PER_ROW);
}

//---------------------------------------------------------------
//Draw string
// s = String to display
// col = color to show
void drawString(String s, CMODE color)
{
  if (scrollDelay == 0)
  {
    scrollText = s;
    scrollColor = color;
    scrollCharPos = 0;
    scrollCharCol = 0;
    scrollOffScreen = 0;
    scrollDelay = SCROLL_SPEED;     //Starts scrolling
  }
}

//---------------------------------------------------------------
//Scroll text left
void scrollTextLeft()
{
  uint8_t bits;
  uint8_t mask;

  //Scroll screen buffer left
  for (int8_t c = 0; c < 8; c++)
  {
    for (int8_t r = 0; r < 8; r++)
    {
      setPixel(r, c, (c == 7) ? C_BLACK : getPixel(r, c + 1));
    }
  }

  //Sixth character column is blank for letter spacing
  if (scrollOffScreen == 0 && scrollCharCol < 5)
  {
    char ch = scrollText[scrollCharPos];
    if (ch >= 48 && ch <= 90)
    {
      //Get bits in the next column and output to buffer
      bits = pgm_read_byte(&font5x7[ch-48][scrollCharCol]);
      mask = 0x40;
      for(int8_t r = 0; r < 7; r++)
      {
        if (bits & mask)
        {
          setPixel(7 - r, 7, scrollColor);
        }
        mask = mask >> 1;
      }
    }
  }

  if (scrollOffScreen > 0)
  {
    scrollOffScreen--;
    if (scrollOffScreen == 0)
    {
      //Stop scrolling
      scrollDelay = 0;
    }
  }
  else
  {
    scrollCharCol++;
    if (scrollCharCol == 6)
    {
      scrollCharCol = 0;
      scrollCharPos++;
      if (scrollCharPos == scrollText.length())
      {
        //All text has been outputted, just wait until it is scrolled of the screen
        scrollOffScreen = 8;
      }
    }
  }
  refresh();
}

//---------------------------------------------------------------
//Draw character
// x = column (0-7) 0 being farest left hand and 7 being farest right
// ch = ASCII character
// col = color to show
void drawCharacter(int8_t x, char ch, CMODE color)
{
  uint8_t bits;
  uint8_t mask;
  if (ch >= 48 && ch <= 90)
  {
    ch = ch - 48;
    for(int c = 0; c < 6; c++)
    {
      int8_t pos = c + x;
      if (pos >= 0 && pos < 8)
      {
        if (c == 5)
        {
          //Blank column for character spacing
          for(int r = 0; r < 7; r++)
          {
            setPixel(r, pos, C_BLACK);
          }
        }
        else
        {
          bits = pgm_read_byte(&font5x7[ch][c]);
          mask = 0x40;
          for(int r = 0; r < 7; r++)
          {
            if (bits & mask)
            {
              setPixel(7 - r, pos, color);
            }
            mask = mask >> 1;
          }
        }
      }
    }
  }
}

//---------------------------------------------------------------
//Sets the bit in the 6 byte array that corresponds to the physical column and row
// r = row (0 - top row to 7 - bottom row)
// c = column (0 to 7)
// color = color to set pixel
// on = true to switch bit on, false to switch bit off
void setPixel(int8_t r, int8_t c, CMODE color)
{
  if (r >= 0 && r < 8 && c >= 0 && c < 8)
  {
    switch (color)
    {
      case C_BLACK:
        setBitInArray(r, mapColumnRed(c), false);
        setBitInArray(r, mapColumnGrn(c), false);
        break;
            
      case C_RED:
        setBitInArray(r, mapColumnRed(c), true);
        setBitInArray(r, mapColumnGrn(c), false);
        break;
      
      case C_GRN:
        setBitInArray(r, mapColumnRed(c), false);
        setBitInArray(r, mapColumnGrn(c), true);
        break;
      
      case C_ORG:
        setBitInArray(r, mapColumnRed(c), true);
        setBitInArray(r, mapColumnGrn(c), true);
        break;
    }
  }
}

//---------------------------------------------------------------
//Get the color of the bit that corresponds to the physical column and row
// r = row (0 - top row to 7 - bottom row)
// c = column (0 to 7)
// Returns color of pixel (BLACK, RED, GREEN, ORANGE)
CMODE getPixel(int8_t r, int8_t c)
{
  bool red = getBitInArray(r, mapColumnRed(c));
  bool grn = getBitInArray(r, mapColumnGrn(c));
  if (red && grn)
  {
    return C_ORG;
  }
  else if (red)
  {
    return C_RED;
  }
  else if (grn)
  {
    return C_GRN;
  }
  return C_BLACK;
}

//---------------------------------------------------------------
//Maps matrix, column and color to LED column number
// c = column (0-7) 0 being farest left hand and 7 being farest right
// g = green - true for green, false for red
// returns physical column (0 to 47)
int8_t mapColumn(int8_t c, bool g)
{
  return ((c < 4) ? (8 + (c << 1) + ((g) ? 0 : 1)) : (8 - ((c - 3) << 1) + ((g) ? 1 : 0)));
}

//---------------------------------------------------------------
//Maps matrix and red column to LED column number
// c = column (0-7) 0 being farest left hand and 7 being farest right
// returns physical column (0 to 47)
int8_t mapColumnRed(int8_t c)
{
  return ((c < 4) ? (9 + (c << 1)) : (8 - ((c - 3) << 1)));
}

//---------------------------------------------------------------
//Maps matrix and green column and color to LED column number
// c = column (0-7) 0 being farest left hand and 7 being farest right
// returns physical column (0 to 47)
int8_t mapColumnGrn(int8_t c)
{
  return ((c < 4) ? (8 + (c << 1)) : (9 - ((c - 3) << 1)));
}

//---------------------------------------------------------------
//Sets the bit in the 6 byte array that corresponds to the physical column and row
// r = row (0 - top row to 7 - bottom row)
// c = column (0 to 15)
// on = true to switch bit on, false to switch bit off
void setBitInArray(int8_t r, int8_t c, bool on)
{
  uint8_t by = c >> 3;
  uint8_t bi = c - (by << 3);
  //Serial.println("r:" + String(7 - r) + ", c:" + String(c) + ", by:" + String(by) + ", bi:" + String(bi));
  if (on)
  {
    ledNext[7 - r][by] |= (1 << bi);
  }
  else
  {
    ledNext[7 - r][by] &= ~(1 << bi);
  }
}

//---------------------------------------------------------------
//Gets the bit that corresponds to the physical column and row
// r = row (0 - top row to 7 - bottom row)
// c = column (0 to 15)
// returns true if bit on
bool getBitInArray(int8_t r, int8_t c)
{
  uint8_t by = c >> 3;
  uint8_t bi = c - (by << 3);
  return (ledNext[7 - r][by] & (1 << bi));
}

//---------------------------------------------------------------
//Clears the working buffer
void clearDisplay()
{
  //Clear out ledStates array
  for (int r = 0; r < ROWS; r++)
  {
    for (int c = 0; c < BYTES_PER_ROW; c++)
    {
      ledNext[r][c] = 0;
    }
  }
}

} //namespace