//
// hello.SSD1306.c
//
// SSD1306 128x64 OLED hello-world
//
// Neil Gershenfeld 11/2/19
// (c) Massachusetts Institute of Technology 2019
//
// This work may be reproduced,modified,distributed,
// performed,and displayed for any purpose. Copyright is
// retained and must be preserved. The work is provided
// as is; no warranty is provided,and users accept all 
// liability.
//

#include <avr/io.h>
#include <util/delay.h>
#include <avr/pgmspace.h>
#include <stdlib.h>

#define output(directions,pin) (directions |= pin) // set port direction for output
#define input(directions,pin) (directions &= (~pin)) // set port direction for input
#define set(port,pin) (port |= pin) // set port pin
#define clear(port,pin) (port &= (~pin)) // clear port pin
#define pin_test(pins,pin) (pins & pin) // test for port pin

#define I2C_slave_address 0x3C
//#define I2C_slave_address 0x3D
//#define I2C_slave_address 0x78
//#define I2C_slave_address 0x7A
#define I2C_delay() _delay_us(5)
#define SCL_pin (1 << PB4)
#define SCL_pins PINB
#define SCL_port PORTB
#define SCL_direction DDRB
#define SDA_pin (1 << PB3)
#define SDA_pins PINB
#define SDA_port PORTB
#define SDA_direction DDRB

void SCL_write(char bit) {
   //
   // write SCL bit
   //
   if (bit == 0) {
      output(SCL_direction,SCL_pin);
      clear(SCL_port,SCL_pin);
      }
   else {
      input(SCL_direction,SCL_pin);
      while (pin_test(SCL_pins,SCL_pin) == 0); // check for clock stretching
      }
   }

void SDA_write(char bit) {
   //
   // write SDA bit
   //
   if (bit == 0) {
      output(SDA_direction,SDA_pin);
      clear(SDA_port,SDA_pin);
      }
   else
      input(SDA_direction,SDA_pin);
   }

void I2C_init() {
   //
   // initialize I2C lines
   //
   SDA_write(1);
   SCL_write(1);
   } 

char I2C_master_write_byte(unsigned char byte) {
   //
   // master write I2C byte
   //
   unsigned char bit;
   //
   // loop over bits
   //
   for (bit = 0; bit < 8; ++bit) {
      if ((byte & 0x80) == 0)
         SDA_write(0);
      else
         SDA_write(1);
      SCL_write(1);
      I2C_delay();
      SCL_write(0);
      I2C_delay();
      byte <<= 1;
      }
   //
   // check for ACK
   //
   SDA_write(1);
   SCL_write(1);
   I2C_delay();
   if (pin_test(SDA_pins,SDA_pin) != 0) {
      //
      // no ACK,return 1
      //
      return 1;	
      }
   //
   // yes ACK,return 0
   //
   SCL_write(0);
   I2C_delay();
   return 0;
   }	

char I2C_master_write(unsigned char* data,unsigned char nbytes,unsigned char slave_address) {
   //
   // I2C master write
   //
   unsigned char index,ret,slave_address_write;
   //
   // send start
   //
   SDA_write(0);
   I2C_delay();
   SCL_write(0);	
   I2C_delay();
   //
   // send slave address
   //
   slave_address_write = slave_address << 1;
   if (I2C_master_write_byte(slave_address_write) != 0)
      //
      // no ACK,return 1
      //
      return 1;
   //
   // loop over bytes
   //
   for (index = 0; index < nbytes; ++index) {
      ret = I2C_master_write_byte(data[index]);
      if (ret != 0)
         //
         // no ACK,return 1
         //
         break;
      //
      // yes ACK,continue
      //	
      }
   //
   // send stop
   //
   SCL_write(1);
   I2C_delay();
   SDA_write(1);
   I2C_delay();
   return ret;
   }

static const uint8_t MonospaceBold7x8[] PROGMEM = {0,0,0,0,0,0,0,0,0,0,223,223,0,0,0,0,7,0,7,0,0,32,228,62,231,124,39,4,0,76,154,255,154,112,0,39,37,23,232,168,228,0,0,112,247,159,241,192,240,0,0,0,7,0,0,0,0,0,24,126,195,0,0,0,0,195,126,24,0,0,0,18,12,63,12,18,0,0,16,16,124,16,16,0,0,128,112,48,0,0,0,0,0,48,48,48,0,0,0,0,192,192,0,0,0,0,0,192,56,6,1,0,0,126,255,129,137,255,126,0,129,129,255,255,128,128,0,129,193,161,153,143,134,0,129,137,137,137,247,118,0,48,44,38,255,255,32,0,143,143,137,137,249,113,0,124,255,139,137,249,112,0,1,129,241,125,31,3,0,118,247,137,137,247,118,0,14,159,145,209,255,62,0,0,204,204,0,0,0,0,0,204,204,0,0,0,0,48,48,120,72,72,204,0,40,40,40,40,40,40,0,204,72,72,120,48,48,0,2,217,215,7,0,0,124,130,57,69,69,254,0,0,192,252,47,47,252,192,0,255,255,137,137,247,118,0,60,126,195,129,129,66,0,255,255,129,129,255,60,0,255,255,137,137,137,129,0,255,255,9,9,9,1,0,60,126,195,145,241,242,0,255,255,8,8,255,255,0,129,129,255,255,129,129,0,64,128,129,129,255,127,0,255,255,24,62,227,193,0,255,255,128,128,128,128,0,255,254,28,28,254,255,0,255,255,14,112,255,255,0,126,255,129,129,255,126,0,255,255,17,17,31,14,0,126,255,129,129,255,126,0,255,255,17,17,111,206,128,78,143,153,153,241,114,0,1,1,255,255,1,1,0,127,255,128,128,255,127,0,3,63,240,240,63,3,15,255,240,12,240,255,15,0,129,231,60,60,231,129,0,1,15,252,252,15,1,0,193,225,185,141,135,131,0,0,255,255,129,0,0,0,1,6,56,192,0,0,0,0,129,255,255,0,0,4,6,3,3,6,4,0,128,128,128,128,128,128,128,0,1,3,2,0,0,0,0,96,244,148,148,252,248,0,255,255,136,136,248,112,0,120,252,204,132,132,132,0,112,248,136,136,255,255,0,120,252,148,148,156,152,0,8,254,255,9,9,0,0,28,190,162,162,254,126,0,255,255,8,8,248,240,0,136,136,251,251,128,128,0,136,136,251,123,0,0,0,255,255,16,124,196,128,1,1,127,255,128,128,0,0,252,252,4,252,4,252,0,252,252,4,4,252,248,0,120,252,132,132,252,120,0,254,254,34,34,62,28,0,28,62,34,34,254,254,0,0,252,252,4,4,4,0,88,156,180,180,228,104,4,4,255,255,132,132,0,0,124,252,128,128,252,252,0,12,124,224,224,124,12,12,252,224,16,224,252,12,0,132,204,120,120,204,132,0,130,142,248,56,14,2,0,196,228,164,148,156,140,0,16,16,239,239,129,129,0,0,0,255,0,0,0,0,129,129,239,239,16,16,0,16,16,16,32,32,32};

static const uint8_t MonospaceBold10x16lo[] PROGMEM = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,254,254,0,0,0,0,0,0,30,30,0,0,30,30,0,0,0,48,176,248,62,50,240,254,62,48,0,112,248,216,254,152,152,0,0,0,28,34,162,162,156,64,64,32,32,0,0,0,220,126,230,198,134,12,128,128,0,0,0,0,30,30,0,0,0,0,0,0,0,224,252,30,2,0,0,0,0,0,2,30,252,224,0,0,0,0,0,72,120,48,254,48,120,72,0,0,0,128,128,128,240,240,128,128,128,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,192,240,60,14,2,0,0,240,252,14,198,198,14,252,248,0,0,0,12,6,254,254,0,0,0,0,0,12,6,6,6,134,198,124,56,0,0,12,6,198,198,198,198,252,56,0,0,128,192,112,24,14,254,254,0,0,0,254,126,102,102,102,230,198,128,0,0,240,252,206,102,102,230,204,128,0,0,6,6,6,6,230,254,62,14,0,0,56,252,198,198,198,198,252,56,0,0,120,252,206,134,134,206,252,248,0,0,0,0,0,224,224,0,0,0,0,0,0,0,0,224,224,0,0,0,0,0,128,128,192,64,96,96,32,48,0,0,96,96,96,96,96,96,96,96,0,0,48,32,96,96,64,192,128,128,0,0,12,6,134,198,102,126,28,0,0,224,240,56,156,204,204,220,248,240,0,0,0,192,252,62,62,252,192,0,0,0,254,254,198,198,198,198,252,60,0,0,240,252,12,6,6,6,6,12,0,0,254,254,6,6,6,12,252,240,0,0,254,254,198,198,198,198,198,6,0,0,254,254,198,198,198,198,198,6,0,0,240,252,12,6,134,134,134,140,0,0,254,254,192,192,192,192,254,254,0,0,0,6,6,254,254,6,6,0,0,0,0,0,0,6,6,6,254,254,0,0,254,254,224,240,252,14,6,2,0,0,254,254,0,0,0,0,0,0,0,0,254,254,62,240,240,62,254,254,0,0,254,254,30,240,192,0,254,254,0,0,240,252,14,6,6,14,252,240,0,0,254,254,198,198,198,198,124,124,0,0,240,252,14,6,6,14,252,240,0,0,254,254,198,198,198,198,252,60,0,0,56,124,230,198,198,198,140,0,0,0,6,6,6,254,254,6,6,6,0,0,254,254,0,0,0,0,254,254,0,0,6,254,252,0,0,252,254,6,0,30,254,224,0,240,240,0,224,254,30,0,2,14,62,248,248,62,14,2,0,2,14,62,120,224,224,120,62,14,2,0,6,6,134,198,246,126,30,14,0,0,0,0,254,254,2,2,0,0,0,0,2,14,56,224,128,0,0,0,0,0,0,2,2,254,254,0,0,0,0,16,24,28,14,6,14,28,24,16,0,0,0,0,0,0,0,0,0,0,0,0,0,1,3,6,4,0,0,0,0,0,0,96,48,176,176,176,240,224,0,0,254,254,96,48,48,112,224,192,0,0,192,224,112,48,48,48,48,96,0,0,192,224,112,48,48,96,254,254,0,0,192,224,176,176,176,176,224,192,0,0,48,48,252,254,54,54,54,0,0,0,192,224,112,48,48,96,240,240,0,0,254,254,96,48,48,48,240,224,0,0,0,48,48,247,247,0,0,0,0,0,0,48,48,247,247,0,0,0,0,0,254,254,128,224,112,48,16,0,0,0,6,6,254,254,0,0,0,0,0,0,240,240,48,240,224,48,240,224,0,0,240,240,96,48,48,48,240,224,0,0,192,224,112,48,48,112,224,192,0,0,240,240,96,48,48,112,224,192,0,0,192,224,112,48,48,96,240,240,0,0,0,240,240,96,48,48,48,48,0,0,224,240,176,176,176,176,48,96,0,0,48,48,252,252,48,48,48,0,0,0,240,240,0,0,0,0,240,240,0,0,48,240,224,0,0,224,240,48,0,112,240,0,0,192,192,0,0,240,112,0,16,48,240,192,192,240,48,16,0,0,16,240,240,128,0,240,240,48,0,0,48,48,48,48,176,240,112,48,0,0,0,0,0,252,254,2,2,0,0,0,0,0,0,254,254,0,0,0,0,0,0,2,2,254,252,0,0,0,0,0,128,192,192,192,128,128,128,192,0,0,0,0,0};

static const uint8_t MonospaceBold10x16hi[] PROGMEM = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,25,25,0,0,0,0,0,0,0,0,0,0,0,0,0,0,3,27,31,3,3,31,15,3,3,0,0,12,24,24,127,25,31,15,0,0,1,1,0,0,14,17,17,17,14,0,0,7,15,28,24,25,31,30,31,19,0,0,0,0,0,0,0,0,0,0,0,0,0,7,63,120,64,0,0,0,0,0,64,120,63,7,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,1,1,1,15,15,1,1,1,0,0,0,0,64,124,60,0,0,0,0,0,0,3,3,3,3,3,0,0,0,0,0,0,0,28,28,0,0,0,0,0,32,56,30,7,1,0,0,0,0,0,3,15,28,24,24,28,15,7,0,0,24,24,24,31,31,24,24,24,0,0,24,28,30,27,25,24,24,24,0,0,12,24,24,24,24,25,15,15,0,0,3,3,3,3,3,31,31,3,0,0,12,24,24,24,24,28,15,7,0,0,7,15,28,24,24,28,15,7,0,0,0,16,28,15,3,0,0,0,0,0,15,15,24,24,24,24,15,15,0,0,0,12,25,25,25,28,15,3,0,0,0,0,0,28,28,0,0,0,0,0,0,0,64,124,60,0,0,0,0,0,1,1,3,2,6,6,4,12,0,0,6,6,6,6,6,6,6,6,0,0,12,4,6,6,2,3,1,1,0,0,0,0,27,27,0,0,0,0,0,7,31,56,115,103,102,102,119,39,0,0,24,31,15,3,3,15,31,24,0,0,31,31,24,24,24,24,31,15,0,0,3,15,12,24,24,24,24,12,0,0,31,31,24,24,24,12,15,3,0,0,31,31,24,24,24,24,24,24,0,0,31,31,0,0,0,0,0,0,0,0,3,15,12,24,25,25,31,15,0,0,31,31,0,0,0,0,31,31,0,0,0,24,24,31,31,24,24,0,0,0,12,24,24,24,24,24,15,15,0,0,31,31,0,0,3,15,30,24,0,0,31,31,24,24,24,24,24,24,0,0,31,31,0,1,1,0,31,31,0,0,31,31,0,0,3,30,31,31,0,0,3,15,28,24,24,28,15,3,0,0,31,31,0,0,0,0,0,0,0,0,3,15,28,24,24,60,111,7,0,0,31,31,0,0,1,3,31,30,16,0,12,24,24,24,24,25,15,15,0,0,0,0,0,31,31,0,0,0,0,0,7,15,28,24,24,28,15,7,0,0,0,0,31,31,31,31,0,0,0,0,31,31,30,1,1,30,31,31,0,0,16,28,31,3,3,31,28,16,0,0,0,0,0,31,31,0,0,0,0,0,28,30,31,27,24,24,24,24,0,0,0,0,127,127,64,64,0,0,0,0,0,0,0,0,3,14,56,32,0,0,0,64,64,127,127,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,14,31,27,25,25,13,31,31,0,0,31,31,12,24,24,28,15,7,0,0,7,15,28,24,24,24,24,12,0,0,7,15,28,24,24,12,31,31,0,0,7,15,29,25,25,25,25,13,0,0,0,0,31,31,0,0,0,0,0,0,7,111,220,216,216,204,255,127,0,0,31,31,0,0,0,0,31,31,0,0,24,24,24,31,31,24,24,24,0,0,192,192,192,255,127,0,0,0,0,0,31,31,1,3,7,30,24,16,0,0,0,0,15,31,24,24,24,0,0,0,31,31,0,31,31,0,31,31,0,0,31,31,0,0,0,0,31,31,0,0,7,15,28,24,24,28,15,7,0,0,255,255,12,24,24,28,15,7,0,0,7,15,28,24,24,12,255,255,0,0,0,31,31,0,0,0,0,0,0,0,12,25,25,25,25,27,31,14,0,0,0,0,15,31,24,24,24,0,0,0,15,31,24,24,24,12,31,31,0,0,0,1,15,30,30,15,1,0,0,0,7,31,30,3,3,30,31,7,0,0,16,24,30,7,7,30,24,16,0,0,0,192,195,255,63,15,1,0,0,0,24,28,30,27,25,24,24,24,0,0,0,1,1,126,254,128,128,0,0,0,0,0,0,255,255,0,0,0,0,0,0,128,128,254,126,1,1,0,0,0,1,0,0,0,1,1,1,0,0,0,0,0,0};

void OLEDcommand(uint8_t c) {
   static uint8_t data[2];
   data[0] = 0;
   data[1] = c;
   I2C_master_write(data,2,I2C_slave_address);
   }

void OLEDcommands(uint8_t c1,uint8_t c2) {
   static uint8_t data[3];
   data[0] = 0;
   data[1] = c1;
   data[2] = c2;
   I2C_master_write(data,3,I2C_slave_address);
   }

void OLEDdata(uint8_t d) {
   static uint8_t data[2];
   data[0] = 0x40;
   data[1] = d;
   I2C_master_write(data,2,I2C_slave_address);
   }

void OLED7x8string(uint8_t row,uint8_t col,char str[]) {
   static uint8_t index,offset,pointer;
   static char chr;
   OLEDcommands(0x00+(col & 0x0F),0x10+((col >> 4) & 0x0F));
   OLEDcommand(0xB0+row);
   index = 0;
   while (1) {
      chr = str[index];
      if (chr == '\0')
         break;
      pointer = chr-' ';
      for (offset = 0; offset < 7; ++offset) {
         OLEDdata(pgm_read_byte(&(MonospaceBold7x8[7*pointer+offset])));
         }
      ++index;
      }
   }

void OLED10x16string(uint8_t row,uint8_t col,char str[]) {
   static uint8_t index,offset,pointer;
   static char chr;
   OLEDcommands(0x00+(col & 0x0F),0x10+((col >> 4) & 0x0F));
   OLEDcommand(0xB0+row);
   index = 0;
   while (1) {
      chr = str[index];
      if (chr == '\0')
         break;
      pointer = chr-' ';
      for (offset = 0; offset < 10; ++offset) {
         OLEDdata(pgm_read_byte(&(MonospaceBold10x16lo[10*pointer+offset])));
         }
      ++index;
      }
   OLEDcommands(0x00+(col & 0x0F),0x10+((col >> 4) & 0x0F));
   OLEDcommand(0xB0+row+1);
   index = 0;
   while (1) {
      chr = str[index];
      if (chr == '\0')
         break;
      pointer = chr-' ';
      for (offset = 0; offset < 10; ++offset) {
         OLEDdata(pgm_read_byte(&(MonospaceBold10x16hi[10*pointer+offset])));
         }
      ++index;
      }
   }
void OLED128x64init() {
   uint8_t i,j;
   //
   // init I2C
   //
   I2C_init();
   //
   // init SSD1306
   //
   OLEDcommand(0xae); // display off
   OLEDcommands(0xa8,0x3f); // set multiplex ratio, ratio 63
   OLEDcommands(0xd3,0x00); // set display offset, no offset
   OLEDcommand(0x40); // set display start line
   OLEDcommand(0xa1); // set segment remap col 127 to seg 0
   OLEDcommand(0xc8); // set COM output reverse
   OLEDcommands(0xda,0x12); // COM pin config, alt bottom to top
   OLEDcommands(0x81,0xff); // set contrast, max contrast
   OLEDcommand(0xa4); // resume to RAM display
   OLEDcommand(0xa6); // normal non-inverted display
   OLEDcommands(0xd5,0x80); // set clock divider, default
   OLEDcommands(0x8d,0x14); // set charge pump, enable
   OLEDcommands(0x20,0x02); // set memory mode, page addressing
   OLEDcommand(0xaf); // display on
   //
   // clear screen
   //
   for (j = 0; j < 8; ++j) {
      OLEDcommands(0x00,0x10);
      OLEDcommand(0xB0+j);
      for (i = 0; i < 128; ++i) OLEDdata(0);
      }
   }

int main(void) {
   //
   // main
   //
   uint16_t count;
   char str[3];
   //
   // set clock divider to /1
   //
   CLKPR = (1 << CLKPCE);
   CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0);
   //
   // initialize OLED
   //
   OLED128x64init();
   //
   // static text
   //
   OLED7x8string(0,0,"Hello World!");
   OLED7x8string(1,28,"in a 7x8 font");
   OLED10x16string(2,0,"Hello World!");
   OLED10x16string(4,0,"in 10x16 font");
   OLED10x16string(6,0,"Count:");
   //
   // dynamic text
   //
   count = 0;
   while (1) {
      itoa(count,str,10);
      OLED10x16string(6,60,str);
      ++count;
      if (count == 1000) {
         OLED10x16string(6,80," ");
         count = 0;
         }
      }
   }