controlling a large 16 segment display and a rotary encoder using only an atmel328p

big_character.pde

#include <avr/pgmspace.h>

#define ENC_A 14
#define ENC_B 15
#define ENC_PORT PINC

const prog_uint8_t character_map[][2] = {
  { B00000000, B00000000 }, // space
  { B00000010, B00000100 }, // ! 32
  { B00101000, B00000000 }, // "
  { B11111111, B11111111 }, // #
  { B11101001, B10010111 }, // $
  { B00110101, B10101100 }, // %
  { B01001100, B00110111 }, // &
  { B00000100, B00000000 }, // '
  { B00000100, B00001000 }, // (
  { B00010000, B00100000 }, // )
  { B00011101, B10111000 }, // *
  { B00001001, B10010000 }, // +
  { B00000000, B00100000 }, // ,
  { B00000001, B10000000 }, // -
  { B00000001, B01010010 }, // .
  { B00000100, B00100000 }, // /
  { B11100110, B01100111 }, // 0
  { B00000010, B00000100 }, // 1
  { B11000010, B10100011 }, // 2
  { B11000010, B10000111 }, // 3
  { B00100011, B10000100 }, // 4
  { B11100001, B00001011 }, // 5
  { B11100001, B11000111 }, // 6
  { B11000100, B00010000 }, // 7
  { B11100011, B11000111 }, // 8
  { B11100011, B10000111 }, // 9
  { B00001000, B00010000 }, // :
  { B00001000, B00100000 }, // ;
  { B00000100, B00001000 }, // <
  { B00000001, B10000011 }, // =
  { B00010000, B00100000 }, // >
  { B01000010, B10010000 }, // ?
  { B11100110, B11000011 }, // @
  { B11100011, B11000100 }, // A
  { B11001010, B10010111 }, // B
  { B11100000, B01000011 }, // C
  { B11001010, B00010111 }, // D
  { B11100001, B01000011 }, // E
  { B11100001, B01000000 }, // F
  { B11100000, B11000111 }, // G
  { B00100011, B11000100 }, // H
  { B11001000, B00010011 }, // I
  { B00000010, B01000111 }, // J
  { B00100101, B01001000 }, // K
  { B00100000, B01000011 }, // L
  { B00110110, B01000100 }, // M
  { B00110010, B01001100 }, // N
  { B11100010, B01000111 }, // O
  { B11100011, B11000000 }, // P
  { B11100010, B01001111 }, // Q
  { B11100011, B11001000 }, // R
  { B11100001, B10000111 }, // S
  { B11001000, B00010000 }, // T
  { B00100010, B01000111 }, // U
  { B00100100, B01100000 }, // V
  { B00100010, B01101100 }, // W
  { B00010100, B00101000 }, // X
  { B00010100, B00010000 }, // Y
  { B11000100, B00100011 }, // Z
  { B01001000, B00010001 }, // [
  { B00010000, B00001000 }, // backslash
  { B10001000, B00010010 }, // ]
  { B00000000, B00101000 }, // ^
  { B00000000, B00000011 }, // _
  { B00010000, B00000000 } // ` 96
// { 123
// |
// }
// ~
};

/*
 - -
|\|/|
 - -
|/|\|
 - -
*/

/* returns change in encoder state (-1,0,1) */
int8_t read_encoder()
{
  static int8_t enc_states[] = {0,-1,1,0,1,0,0,-1,-1,0,0,1,0,1,-1,0};
  static uint8_t old_AB = 0;
  old_AB <<= 2;                   //remember previous state
  old_AB |= ( ENC_PORT & 0x03 );  //add current state
  return ( enc_states[( old_AB & 0x0f )]);
}

void write_character(char c) {
  uint8_t mask;
  
  // All Off
  PORTD |= B11111100;
  PORTB |= B00111111;
  PORTC |= B00111100;
  for (int i=0; i<16; i++) {
    if (i<8)
      mask = ~character_map[c-32][1];
    else
      mask = ~character_map[c-32][0];

/*

PORTD D7 D6  D5  D4  D3  D2  TX RX
PORTB X2 X1  D13 D12 D11 D10 D9 D8
PORTC NC RST A5  A4  A3  A2  A1 A0

PIN  19  18  17  16  15  14  13  12
AVR  A5  A4  A3  A2  D13 D12 D11 D10
SEG  14  13  16  12  11  15  10  8

PIN  2   3   4   5   6   7   8   9   10
AVR  D2  D3  D4  D5  D6  D7  D8  D9  NC
SEG  9   7   2   6   5   1   4   3   17(DP)
*/

         if (i==0)  { mask <<= 7; mask |= B01111111; PORTD &= mask; }
    else if (i==1)  { mask <<= 3; mask |= B11101111; PORTD &= mask; }
    else if (i==2)  { mask >>= 1; mask |= B11111101; PORTB &= mask; }
    else if (i==3)  { mask >>= 3; mask |= B11111110; PORTB &= mask; }
    else if (i==4)  { mask <<= 2; mask |= B10111111; PORTD &= mask; }
    else if (i==5)  {             mask |= B11011111; PORTD &= mask; }
    else if (i==6)  { mask >>= 3; mask |= B11110111; PORTD &= mask; }
    else if (i==7)  { mask >>= 5; mask |= B11111011; PORTB &= mask; }
    else if (i==8)  { mask <<= 2; mask |= B11111011; PORTD &= mask; }
    else if (i==9)  { mask <<= 2; mask |= B11110111; PORTB &= mask; }
    else if (i==10) { mask <<= 3; mask |= B11011111; PORTB &= mask; }
    else if (i==11) { mask >>= 1; mask |= B11111011; PORTC &= mask; }
    else if (i==12) {             mask |= B11101111; PORTC &= mask; }
    else if (i==13) {             mask |= B11011111; PORTC &= mask; }
    else if (i==14) { mask >>= 2; mask |= B11101111; PORTB &= mask; }
    else if (i==15) { mask >>= 4; mask |= B11110111; PORTC &= mask; }
  }
}

int d = 400;
void write_string(char* s) {
  uint8_t i=0;
  while (s[i] != '\0') {
    write_character(s[i]);
    i++;
    delay(d);
  }
}


void setup() {
  /* Setup encoder pins as inputs */
  pinMode(ENC_A, INPUT);
  digitalWrite(ENC_A, HIGH);
  pinMode(ENC_B, INPUT);
  digitalWrite(ENC_B, HIGH);
  Serial.begin (115200);

  // Set In/Out
  DDRD  |= B11111100;
  DDRB  |= B00111111;
  DDRC  |= B00111100;

  // All On
  PORTD &= B00000011;
  PORTB &= B11000000;
  PORTC &= B11000011;

  // All Off
  PORTD |= B11111100;
  PORTB |= B00111111;
  PORTC |= B00111100;
  
  write_character('A');
}

int changes = 0;
int last_counter = 0;
int current_char = 33;

void loop() {
  write_string("HELLO ABIGAIL, HOW ARE YOU TODAY?");

  // All Off
  PORTD |= B11111100;
  PORTB |= B00111111;
  PORTC |= B00111100;
  
  delay(2000);
  
/*
  static uint8_t counter = 0;      //this variable will be changed by encoder input
  int8_t tmpdata;
  tmpdata = read_encoder();

  if( tmpdata ) {
    Serial.print("Counter value: ");
    Serial.println(counter, DEC);
    counter += tmpdata;
    changes++;
  }


  if ( changes == 4 ) {
    Serial.print("Last Counter: ");
    Serial.println(last_counter);
    Serial.print("Counter: ");
    Serial.println(counter, DEC);

    if (counter > last_counter) {
      current_char++;
      d--;
    }      
    else {
      current_char--;
      d++;
    }

    if (current_char > 96)
      current_char = 32;
    if (current_char < 32)
      current_char = 96;

    Serial.print("current_char: ");
    Serial.println(current_char);

    last_counter = counter;
    changes = 0;

//    write_character(current_char);
  }

/*
  // all on
  PORTD &= B00000011;
  PORTB &= B11000000;
  PORTC &= B11000011;

  delay(d);

  // all off
  PORTD |= B11111100;
  PORTB |= B00111111;
  PORTC |= B00111100;

  delay(d);
*/
}