/*
 * uart_echo.c
 *
 * Created: 16.08.2018 17:39:49
 * Author : jens
 */ 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <avr/io.h>
#include <avr/interrupt.h>

#include "fifo.h"
#include "adc.h"
#include "port.h"
#include "timer.h"
#include "uart.h"
#include "i2c.h"
#include "mcp42x6.h"

#define ARDUINO_NANO

#ifdef ARDUINO_NANO
#define F_CPU			(16000000UL)	// MHz
#else
#define F_CPU			(18432000UL)	// MHz
#endif
#define USART_BAUDRATE	38400UL
#define BAUD_PRESCALE	(((F_CPU / (USART_BAUDRATE * 16UL))) - 1)
#define TIMER_RELOAD	(0xFFFF-(F_CPU/1024/4-1))
static uint8_t ledState = 0;
static int16_t adc_value[16];
static size_t adc_ch = 0;
static Fifo messageFifo;

enum MessageCode
{
	NOP=0,
	Command,
	Uart,
	Timer,
	AdcComplete,
	Error = 0xFF
};

typedef struct _sMsg_t
{
	uint8_t code;
	uint8_t data;
} Msg_t;

ISR(ADC_vect)
{
	int16_t value_low = (int16_t)ADCL;
	int16_t value_high = (int16_t)ADCH;
	ADCSRA |= (1<<ADIF);
	int16_t value = value_high << 8 | value_low;
	
	if (((adc_value[adc_ch] - value) < -1) || ((adc_value[adc_ch] - value) > 1))
	{
		Msg_t msg = {AdcComplete, adc_ch};
		fifo_push(&messageFifo, &msg);
	}
	
	adc_value[adc_ch] = value;
	adc_ch++;
	if (adc_ch == 16)
	{
		adc_ch = 0;
	}
	adc_start_conversion(adc_ch);
}

ISR(USART_RX_vect)
{
	uint8_t rx_data = UDR0;
	if (rx_data == ' ')
	{
		Msg_t msg = {Error, rx_data};
		fifo_push(&messageFifo, &msg);
	} 
	else if (rx_data >= '0' &&  rx_data <= '9')
	{
		Msg_t msg = {Command, rx_data};
		fifo_push(&messageFifo, &msg);
	}
	Msg_t msg = {Uart, rx_data};
	fifo_push(&messageFifo, &msg);
}

ISR (TIMER1_OVF_vect)    // Timer1 ISR
{
	Msg_t msg = {Timer, ledState};
	fifo_push(&messageFifo, &msg);

	TCNT1 = TIMER_RELOAD;
	ledState++;
	if (ledState == 4)
	{
		ledState = 0;
	} 
}

FILE uart_file = FDEV_SETUP_STREAM(uart_putchar, NULL, _FDEV_SETUP_WRITE);

int main(void)
{
	fifo_init(&messageFifo, 64, sizeof(Msg_t), "Fifo");
	
    /* Replace with your application code */
	uart_init(BAUD_PRESCALE);
	timer_init(TIMER_RELOAD);
	adc_init();
	i2c_init();
	
	stdout = &uart_file;
	printf("UART test version 1.0\n\n");

	uint8_t dac_cmd[] = {0x00, 0x00, 0x00};		// 6.1 Write Volatile DAC Register (C2:C0 = ‘00x’)
	size_t res = MCP47x6_write_volatile_mem(0x0000, dac_cmd, sizeof(dac_cmd));
	i2c_send(0x60, I2C_WRITE, dac_cmd, res);

	sei();
	adc_start_conversion(adc_ch);

	char cmdStr[16];
	size_t cmdStrSize = 0;
	while (1) 
    {
		Msg_t msg;
		if (!fifo_isEmpty(&messageFifo))
		{
			cli();
			fifo_pop(&messageFifo, &msg);
			sei();
			
			switch(msg.code)
			{
				case Uart:
				{
					cmdStr[cmdStrSize] = 0;
					if (cmdStrSize < sizeof(cmdStr))
					{
						char c = msg.data;
						if (c == 0x0A || c == 0x0D)
						{
							printf("Command : %s\n", cmdStr);
							cmdStrSize = 0;
						}
						else
						{
							cmdStr[cmdStrSize++] = c;
						}
					}
					else
					{
						printf("Invalid command : %s\n", cmdStr);
						cmdStrSize = 0;
					}
				}
				break;

				case Command:
				{
					printf("Command : %c\n", msg.data);
					uint8_t dac_cmd[] = {0x00, 0x00};					// 6.2 Write Volatile Memory (C2:C0 = ‘010’)
					size_t res = MCP47x6_write_volatile_dac((uint16_t)(msg.data-'0')<<8, dac_cmd, sizeof(dac_cmd));
					i2c_send(0x60, I2C_WRITE, dac_cmd, res);
				}
				break;
			
				case AdcComplete:
				{
					size_t ch = msg.data;
					if (ch == 6)
					{
						printf("ADC=%d\n", adc_value[ch]);
						uint8_t dac_cmd[] = {0x00, 0x00};					// 6.2 Write Volatile Memory (C2:C0 = ‘010’)
						size_t res = MCP47x6_write_volatile_dac(adc_value[ch]<<2, dac_cmd, sizeof(dac_cmd));
						i2c_send(0x60, I2C_WRITE, dac_cmd, res);
					}
				}
				break;

				case Timer:
				switch(msg.data)
				{
					case 0:
					DDRB = (DDRB & 0xFC) | 0x00;
					printf("----------- Timer -----------\n");
					break;
					case 1:
					DDRB = (DDRB & 0xFC) | 0x01;
					break;
					case 2:
					DDRB = (DDRB & 0xFC) | 0x03;
					break;
					case 3:
					DDRB = (DDRB & 0xFC) | 0x02;
					break;
				}
				break;

				case Error:
				printf("Error!!!\n");
				break;
			}
		}
    }
}