/*
 * main.c
 *
 *  Created on: 22 нояб. 2018 г.
 *      Author: maxx
 */
#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <compat/deprecated.h>  //sbi, cbi etc..
#include "avr/wdt.h" // WatchDog
#include <stdio.h>  // printf etc..
#include "uart_extd.h"

//#include <stdlib.h> // itoa etc..

#define PRINTF_EN 1
#if PRINTF_EN
#define PRINTF(FORMAT,args...) printf_P(PSTR(FORMAT),##args)
#else
#define PRINTF(...)
#endif

/*
 * m1284p minimum template, with one button & one led
 */

//M644P/M1284p Users LEDS:
//LED1/PORTC.4- m644p/m1284p maxxir
#define led1_conf()      DDRC |= (1<<DDC4)
#define led1_high()      PORTC |= (1<<PORTC4)
#define led1_low()       PORTC &= ~(1<<PORTC4)
#define led1_tgl()     PORTC ^= (1<<PORTC4)
#define led1_read()     (PORTC & (1<<PORTC4))

#define sw1_conf()      {DDRC &= ~(1<<DDC5); PORTC |= (1<<PORTC5);}
#define sw1_read()     (PINC & (1<<PINC5))

//*********Global vars
#define TICK_PER_SEC 1000UL
volatile unsigned long _millis; // for millis tick !! Overflow every ~49.7 days

//*********Program metrics
const char compile_date[] PROGMEM    = __DATE__;     // Mmm dd yyyy - Дата компиляции
const char compile_time[] PROGMEM    = __TIME__;     // hh:mm:ss - Время компиляции
const char str_prog_name[] PROGMEM   = "\r\nAtMega1284p v1.2 Base Template 22/11/2018\r\n"; // Program name

#if defined(__AVR_ATmega128__)
const char PROGMEM str_mcu[] = "ATmega128"; //CPU is m128
#elif defined (__AVR_ATmega2560__)
const char PROGMEM str_mcu[] = "ATmega2560"; //CPU is m2560
#elif defined (__AVR_ATmega2561__)
const char PROGMEM str_mcu[] = "ATmega2561"; //CPU is m2561
#elif defined (__AVR_ATmega328P__)
const char PROGMEM str_mcu[] = "ATmega328P"; //CPU is m328p
#elif defined (__AVR_ATmega32U4__)
const char PROGMEM str_mcu[] = "ATmega32u4"; //CPU is m32u4
#elif defined (__AVR_ATmega644P__)
const char PROGMEM str_mcu[] = "ATmega644p"; //CPU is m644p
#elif defined (__AVR_ATmega1284P__)
const char PROGMEM str_mcu[] = "ATmega1284p"; //CPU is m1284p
#else
const char PROGMEM str_mcu[] = "Unknown CPU"; //CPU is unknown
#endif


//FUNC headers
static void avr_init(void);
void timer0_init(void);
static inline unsigned long millis(void);

// RAM Memory usage test
static int freeRam (void)
{
	extern int __heap_start, *__brkval;
	int v;
	int _res = (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval);
	return _res;
}


//******************* MILLIS ENGINE: BEGIN
//ISR (TIMER0_COMP_vect )
ISR (TIMER0_COMPA_vect)
{
	// Compare match Timer0
	// Here every 1ms
	_millis++; // INC millis tick
	// Тест мигаем при в ходе в прерывание
	// 500Hz FREQ OUT
	// LED_TGL;
}

static inline unsigned long millis(void)
{
	unsigned long i;
	cli();
	// Atomic tick reading
	i = _millis;
	sei();
	return i;
}
//******************* MILLIS ENGINE: END

//***************** UART0: BEGIN
// Assign I/O stream to UART
/* define CPU frequency in Mhz here if not defined in Makefile */
//#ifndef F_CPU
//#define F_CPU 16000000UL
//#endif

/* 19200 baud */
#define UART_BAUD_RATE      19200
//#define UART_BAUD_RATE      38400

static int uart0_putchar(char ch,FILE *stream);
static void uart0_rx_flash(void);

static FILE uart0_stdout = FDEV_SETUP_STREAM(uart0_putchar, NULL, _FDEV_SETUP_WRITE);
//PS. stdin не переназначаю, т.к. удобнее с ним работать через uart.h - api:

/*
 * Т.е. например так
        c = uart1_getc();
        if (( c & UART_NO_DATA ) == 0)
        {
           uart1_putc( (unsigned char)c );
        }
 При этом чекаем что буфер приема не пуст и опрос идет неблокирующий (+ работаем через UART RX RINGBUFFER),
 а если работаем в стиле stdin->getchar() там опрос блокируется пока символ не будет принят (поллинг)
 через UART1_RX, т.е. неудобно.
*/

// STDOUT UART0 TX handler
static int uart0_putchar(char ch,FILE *stream)
{
	uart_putc(ch);
	return 0;
}

// Очищаем буфер приема UART1 RX (иногда нужно)
static void uart0_rx_flash(void)
{
	// Считываем все из ring-buffer UART1 RX
	unsigned int c;
	do
	{
		c = uart_getc();
	} while (( c & UART_NO_DATA ) == 0); // Check RX1 none-empty

}
//***************** UART0: END

//***************** ADC: BEGIN

#ifndef ADC_DIV
//12.5MHz or over use this ADC reference clock
#define ADC_DIV (1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0) //:128 ADC Prescaler
#endif

#ifndef ADC_REF
// vcc voltage ref default
#define ADC_REF (1<<REFS0)
#endif

void adc_init(void)
{
	ADCSRA = 0;
	ADCSRA |= (ADC_DIV);    // ADC reference clock
	ADMUX |= (ADC_REF);     // Voltage reference
	ADCSRA |= (1<<ADEN);    // Turn on ADC
	ADCSRA |= (1<<ADSC);    // Do an initial conversion because this one is the
	                        // slowest and to ensure that everything is up
							// and running
}

uint16_t adc_read(uint8_t channel)
{
	ADMUX &= 0b11100000;                    //Clear the older channel that was read
	ADMUX |= channel;                //Defines the new ADC channel to be read
	ADCSRA |= (1<<ADSC);                //Starts a new conversion
	while(ADCSRA & (1<<ADSC));            //Wait until the conversion is done

	return ADCW;                    //Returns the ADC value of the chosen channel
}
//***************** ADC: END

int main()
{
	uint8_t prev_sw1 = 1; // VAR for sw1 pressing detect

	// INIT MCU
	avr_init();

	// Print program metrics
	PRINTF("%S", str_prog_name);// Название программы
	PRINTF("Compiled at: %S %S\r\n", compile_time, compile_date);// Время Дата компиляции
	PRINTF(">> MCU is: %S; CLK is: %luHz\r\n", str_mcu, F_CPU);// MCU Name && FREQ
	PRINTF(">> Free RAM is: %d bytes\r\n", freeRam());

	//Short Blink LED 3 times on startup
	unsigned char i = 3;
	while(i--)
	{
		led1_high();
		_delay_ms(100);
		led1_low();
		_delay_ms(400);
		wdt_reset();
	}

    unsigned long prev_millis = 0;
    unsigned long rx_millis = 0;
	unsigned long uptime = 0;
   	uint16_t CharIn;
	while(1)
	{
		//Here at least every 1sec
		wdt_reset(); // WDT reset at least every sec
		if((millis()-prev_millis)>TICK_PER_SEC)
		{
			//Here every 1sec
			wdt_reset(); // WDT reset at least every sec
			prev_millis = millis();
			led1_tgl();
			PRINTF("Uptime %lu sec\r\n", uptime++);
			//PRINTF("ADC5: %d\r\n", adc_read(5));


			//!! SW1 pressing action
			if(!sw1_read())// Check for SW1 pressed every second
			{
				// SW1 is pressed
				//led1_high(); //LED1 ON
				if(prev_sw1)
				{
					//!! Здесь по факту нажатия кнопки (1->0 SW1)
					//!! Debug only
					PRINTF("SW1 is pressed\r\nADC0/PA0 is: %u\r\n", adc_read(0));
					//PRINTF("SW1 is pressed\r\n");
				}//if(prev_sw1)
				prev_sw1 = 0; // Store SW1 state for next iteration
			}//if(!sw1_read())
			else
			{
				// SW1 is unpressed
				//led1_low(); // LED1 OFF
				prev_sw1 = 1;// Store SW1 state for next iteration
			}//if(!sw1_read())else..
		}//if((millis()-prev_millis)>TICK_PER_SEC)

		if((millis()-rx_millis)>0)
		{
			// Here every 1 msec, to check UART RX
			rx_millis = millis();

			// GET UART RX Symbol
		    CharIn = uart_getc();

			// Check if char exist
			// Read until data in RX buffer present
			while (( CharIn & UART_NO_DATA ) == 0)
			{
				wdt_reset(); // WDT reset at least every sec
				//!! Debug only
				//Read data from UART0 RX ring buffer & send back echo
				uart_putc(CharIn+1);
				// GET UART RX Symbol
			    CharIn = uart_getc();
			}
		}//if((millis()-rx_millis)>0)
	}
	return 0;
}

// Timer0
// 1ms IRQ
// Used for millis() timing
void timer0_init(void)
{
	/*
	 *
	 * For M128
	TCCR0 = (1<<CS02)|(1<<WGM01); //TIMER0 SET-UP: CTC MODE & PS 1:64
	OCR0 = 249; // 1ms reach for clear (16mz:64=>250kHz:250-=>1kHz)
	TIMSK |= 1<<OCIE0;	 //IRQ on TIMER0 output compare
	*/
	//For M664p
	TCCR0A = (1<<WGM01); //TIMER0 SET-UP: CTC MODE
	TCCR0B = (1<<CS01)|(1<<CS00); // PS 1:64
	OCR0A = 249; // 1ms reach for clear (16mz:64=>250kHz:250-=>1kHz)
	TIMSK0 |= 1<<OCIE0A;	 //IRQ on TIMER0 output compareA
}

static void avr_init(void)
{
    // Initialize device here.
	// WatchDog INIT
	wdt_enable(WDTO_2S);  // set up wdt reset interval 2 second
	wdt_reset(); // wdt reset ~ every <2000ms

	timer0_init();// Timer0 millis engine init

	// Initial UART Peripheral
    /*
     *  Initialize uart11 library, pass baudrate and AVR cpu clock
     *  with the macro
     *  uart1_BAUD_SELECT() (normal speed mode )
     *  or
     *  uart1_BAUD_SELECT_DOUBLE_SPEED() ( double speed mode)
     */
	// Define Output/Input Stream
#if	(UART_BAUD_RATE == 115200)
	uart_init( UART_BAUD_SELECT_DOUBLE_SPEED(UART_BAUD_RATE,F_CPU) ); // To works without error on 115200 bps/F_CPU=16Mhz
#else
	uart_init( UART_BAUD_SELECT(UART_BAUD_RATE,F_CPU) );
#endif
    stdout = &uart0_stdout;

	//ADC init
	adc_init();
	adc_read(0); //Dummy read


	led1_conf();
	led1_low();// LED1 is OFF


	sw1_conf();//SW1 internal pull-up

	sei(); //re-enable global interrupts

    return;
}