/*WLAN Radio
  Display Ansteuerung
  + Empfang von Sendernamen per UART
  + Verändern der Radiostation durch Tastendruck, übertragen per UART

  Zusammenstellung von Friedemann Wulff-Woesten, www.wulff-woesten.de
  die meisten Codefragmente stammen von www.mikrocontroller.net
  - Danke an alle Jungs dort!

  Display Ansteuerung getestet mit
  + DISPLAYTECH 162A
    bestellt bei Reichelt
  + LCD-Modul TC1602A-09 (sehr trendiges blau!)
    bestellt bei Pollin
  
  verwendeter uController: Atmel ATMega8 - reicht vollkommen aus.
  Compiler: AVR-GCC
  erfolgreich getestet auf 
  Windows (WinAVR), Mac OS X (Crosspack), Ubuntu Linux 11.10 und 11.04

  Danke an Sebastian Paul und Sebastian Müller für alle Erklärungen!

  Fragen / questions: eisenrah@gmail.com*/

////////////////////////////////////////////////////////////////////////////////
// Hier die verwendete Taktfrequenz in Hz eintragen, wichtig!
// edit clock setting here! otherwise timing will be spoiled.
#ifndef F_CPU
#define F_CPU 3686400
#endif
//
////////////////////////////////////////////////////////////////////////////////

// clock speed
#define FOSC F_CPU
// 115200 is default baud rate of OpenWRT - so it should work.
// Please use an external crystal oscillator!
// 3,6864 MHz works fine for me.
#define BAUD 115200
#define MYUBRR FOSC/16/BAUD-1
// longest character line to accept from serial port
#define SER_BUFF_LEN 80

#include <avr/interrupt.h>
#include <util/delay.h>
#include <stdint.h>
#include <avr/io.h>
#include <stdlib.h>
#include "lcd-routines.h"
#include "taster.h"
#include <string.h>
#include <stdio.h>

// serial buffer
unsigned char serbuffer[SER_BUFF_LEN];
// current tuner position
unsigned char tunerpos = 0;
// string with max. 16+1 chars
unsigned char Line[17];
unsigned char OldLine[17];
unsigned char flag = 0;

////////////////////////////////////////////////////////////////////////////////
// UART stuff
////////////////////////////////////////////////////////////////////////////////

void uart_init( unsigned int ubrr)
  {
  // set baud rate
  UBRRH = (unsigned char)(ubrr>>8);
  UBRRL = (unsigned char)ubrr;
  // enable receiver and transmitter
  UCSRB = (1<<RXEN)|(1<<TXEN);
  // set frame format: 8data, 1stop bit
  UCSRC = (1<<URSEL)|(3<<UCSZ0);
  UCSRC &= ~(1<<USBS);
  }

int uart_putc(unsigned char c)
  {
  // wait until UART ready
  while (!(UCSRA & (1<<UDRE)))
    {
    }
  // send char
  UDR = c;
  return 0;
  }

void uart_puts(char *s)
  {
  while (*s)
    {
    // loop as long *s != '\0'
    uart_putc(*s);
    s++;
    }
  }

int uart_getc(void)
  {
  // wait until char is there
  while (!(UCSRA & (1<<RXC)));
  // return char to caller
  return UDR;
  }

void uart_gets(char* Buffer, uint8_t MaxLen)
  {
  uint8_t NextChar;
  uint8_t StringLen = 0;
  /* wait for and receive new char
     collect chars, until
     - \n came by
     - array is full */
  NextChar = uart_getc();
  while ((NextChar != '\n') && (StringLen < MaxLen))
    {
	// do not collect \r char
    if (NextChar != '\r')
      {
      *Buffer++ = NextChar;
      }
    StringLen++;
    NextChar = uart_getc();
    }
  // append '\0' to produce proper c string
  *Buffer = '\0';
  }

////////////////////////////////////////////////////////////////////////////////
// Button stuff
////////////////////////////////////////////////////////////////////////////////

/* 3,6864 MHz clock -> Timer0 produces overflow interrupt every 256µs
   we need get_taster() to be executed every 10ms
   so we call it every 144th time */

SIGNAL (SIG_OVERFLOW0)
  {
  static unsigned char count_ovl0;
  unsigned char ovl0 = count_ovl0+1;
  if (ovl0 >= 144) // if your clock differs from 3,6864 MHz, recalculate this value!
    {
    get_taster (0, PIND & (1<<PD2));
    get_taster (1, PIND & (1<<PD3));
    ovl0 = 0;
    }
  count_ovl0 = ovl0;
  }

void ioinit()
  {
  #if TASTER_LEVEL
    ;
  #else
    PORTD |= 1 << PD2;
    PORTD |= 1 << PD3;
  #endif
  // Timer0 without prescaler
  TCCR0 = 1 << CS00;
  // activate Timer0 overflow interrupt
  TIMSK |= (1 << TOIE0);
}

////////////////////////////////////////////////////////////////////////////////

int main(void)
  {
  ////////////////////////////////////////////////////////////////////////////////
  // initialize USART
  uart_init(MYUBRR);
  DDRB = 0xFF;
  DDRD = 0x00;
  // initialize buttons
  DDRD &= ~(1 << PD2);
  DDRD &= ~(1 << PD3);
  ioinit();

  ////////////////////////////////////////////////////////////////////////////////
  // splash screen rendering
  lcd_init();
  lcd_string("** Wifi Radio **");
  lcd_setcursor( 0, 2 );
  lcd_string("wulff-woesten.de");
  _delay_ms(2000);
  lcd_clear();
  lcd_string("Idee:");
  lcd_setcursor( 0, 2 );
  lcd_string("Sebastian Paul");
  _delay_ms(2000);
  lcd_clear();
  lcd_string("Umsetzung:");
  lcd_setcursor( 0, 2 );
  lcd_string("Friedemann W.-W.");
  _delay_ms(2000);
  lcd_clear();
  lcd_string("Special thanks:");
  lcd_setcursor( 0, 2 );
  lcd_string("Karyna Krynko");
  _delay_ms(2000);
  lcd_clear();
  lcd_string(">>> Verbinde >>>");
  lcd_setcursor( 0, 2 );
  lcd_string("> Bitte warten >");
  do uart_gets( Line, sizeof( Line ) );
  while (!strstr(Line, "AVR Start"));
  lcd_clear();

  ////////////////////////////////////////////////////////////////////////////////
  // set button mode
  tasten[0].mode = TM_LONG;
  tasten[1].mode = TM_SHORT;
  // enable interrupts  
  sei();
  while(1)
    {
      signed char tast = taster;
      switch (tast)
      {
        default:
        case NO_TASTER:
          break;
        case 0:
          // if the button1 is pressed, send new position over serial port
          tunerpos++;
          sprintf(serbuffer, "tuner: %d\n", tunerpos);
          // transmit over serial link
          uart_puts(serbuffer);
          break;
        case 0+TASTER_LONG:
          // if button1 was pressed for a longer time, jump 2 stations forward
          tunerpos = tunerpos + 2;
          sprintf(serbuffer, "tuner: %d\n", tunerpos);
          // transmit over serial link
          uart_puts(serbuffer);
          break;
        case 1:
          // if button2 was pressed go back to first station in playlist
          tunerpos = 1;
          sprintf(serbuffer, "tuner: %d\n", tunerpos);
          // transmit over serial link
          uart_puts(serbuffer);
          break;
      }
      if (tast != NO_TASTER)
      taster = NO_TASTER;
      uart_gets(Line, sizeof(Line));
      if (strcmp(Line, OldLine))
        {
        lcd_clear();
        lcd_home();
        lcd_string("** Wifi Radio **");
        lcd_setcursor( 0, 2 );
        lcd_string(Line);
        strcpy(OldLine, Line);
        }
    }
  return 0;
  }