//==========================================================================
// Project: Radio controlled dual 1 color led strip driver with sound sensor
// Type: firmware
// Name: main.c
// Author: Etienne Meleard
// Creation Date: 2013-02-01
// Tabsize: 4
//==========================================================================


//============================== WARNING ==================================//
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!//
//                                                                         //
// Fuses must be like SUT1 = 1, SUT0 = 1, CKSEL3 = 1, CKSEL2 = 0,          //
// CKSEL1 = 0 and CKSEL0 = 0 to ensure µC is using the crystal as clock    //
// (otherwise it uses the 8MHz internal clock), full swing mode is         //
// mandatory to acheive 8MHz operation.                                   //
//                                                                         //
// CKDIV8 fuse must not be set to avoid clock frequency divided by 8       //
//                                                                         //
// Fuse set or = 1 means checked in ponyprog                               //
//                                                                         //
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!//
//=========================================================================//


// ================= Fuses ================= //

/*FUSES = { // No success writing fuse this way, command line below ...
	.low = (FUSE_SUT1 & FUSE_SUT0 & FUSE_CKSEL3),
	.high = HFUSE_DEFAULT,
	.extended = EFUSE_DEFAULT,
};*/
// Run avrdude -c usbasp -p m8 -U lfuse:w:0xc7:m -U hfuse:w:0xdf:m at first (-F may be needed)


// ================ Includes =============== //

#include <avr/io.h>
#include <sup_avr/io2.h>
#include <avr/interrupt.h>
#include <util/delay.h>


// ================ Pinouts ================ //

#define RX			PORTD.bit0
#define RX_COMPLETE	SIG_USART_RECV

#define SOUND_ADC	7

#define ADDR0		PORTD.bit5
#define ADDR1		PORTD.bit6
#define ADDR2		PORTD.bit7

#define EVAL_STATE	TIMER0_OVERFLOW

#define OUT0		PORTB.bit1
#define LVL0		OCR1A
#define OUT1		PORTB.bit2
#define LVL1		OCR1B

#define LED			PORTD.bit4
#define BLINK LED=1; _delay_ms(150); BLINK LED=0; _delay_ms(150)

#define SDA			PORTC.bit4
#define SCL			PORTC.bit5


// ================ Globals ================ //

#define MODE	0
	#define MODE_FIXED 0
	#define MODE_SOUND 1
#define FIXED_VALUE	1
#define FOO		2
// Must be big enough for 2 times the params
volatile uint8_t params[16] = {
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

volatile uint8_t addr = 0x00;
volatile uint16_t rxbyte = 0x0000;
volatile uint8_t received = 0x00;


// ================ Functions ============== //

void init(void) {
	// USART
	UCSRA = 0x00;
	UCSRB = 0x90;	// Rx enable and Rx irq enable
	UCSRC = 0xa6;	// 8 bits, 1 stop bit, even parity
	UBRR = 103;		// 4800 baud
	
	// ADC (sound sensor)
	ADMUX = 0x00 | SOUND_ADC;	// Ext ref and channel
	ADCSRA = 0xef;				// Enable, start, free running, irq enable, prescaler=128 : 4807conv/s
	
	// Address inputs
	DDRD &= 0x1f;
	PORTD |= 0xe0;	// Pull-up
	
	// State timer
	TCCR0 = 0x05;	// Prescaler=1024 : 30irq/s
	TIMSK |= 0x01;	// Irq enable
	
	// Outputs
	DDRB |= 0x06;
	
	// PWM Timer
	TCCR1A = 0xa1;	// Phase and frequency correct PWM
	TCCR1B = 0x14;	// mode, prescaler=256 : 122Hz
	ICR = 0x007f;	// 128  levels
	
	// Led
	DDRB |= 0x10;
	
	// I2C
	DDRC |= 0x30;
}

// Read params from EEPROM
void loadParams(void) {
	uint8_t param;
	for(param=0; param<16; idx++) {
		while(EECR & (1<<EEWE));
		EEAR = param;
		EECR |= (1<<EERE);
		params[param] = EEDR;
	}
}

// Save new param value into EEPROM
void writeParam(uint8_t param, uint8_t value) {
	while(EECR & (1<<EEWE));
	EEAR = param;
	EEDR = value;
	EECR |= (1<<EEMWE);
	EECR |= (1<<EEWE);
}

// Eval the state of one output
void evalState(uint8_t output) {
	uint8_t offset = 0;
	
	if(output) offset = 8;
	output = output ? *LVL1 : *LVL0;
	
	switch(params[offset + MODE]) {
		case MODE_FIXED :
			output = params[offset + FIXED_VALUE];
			break;
		case MODE_SOUND :
			output = 1.7 * (ADC - 184);				// TODO : measure idle value and evaluate sensitivity or make it a parameter
			break;
	}
}


// =============== Interrupts ============== //

SIGNAL(RX_COMPLETE) {
	uint8_t rxaddr, p, v;
	if(UDR & 0x80) {								// byte 1
		if(rxbyte) {								// already got byte 0
			rxaddr = (rxbyte & 0x0070) >> 4;
			if(rxaddr && (rxaddr != addr)) return;	// not for me
			p = rxbyte & 0x000f;					// get param index with out multiplier
			v = UDR & 0x7f;							// get value
			params[p] = v;							// set param
			writeParam(p, v);						// save param for future restarts
			if(!rxaddr) {							// if broadcast value must be set for both outputs
				params[8 + p] = v;
				writeParam(8 + p, v);
			}
			
			rxbyte = 0x0000;
			received = 1;							// signal rx
		}											// else we just had a second byte without the first one, we discard it
	}else rxbyte = 0xff00 + UDR;					// byte 0
}

SIGNAL(EVAL_STATE) { // 30Hz
	evalState(0);
	evalState(1);
}


// ================== Main ================= //

int main(void) {
	uint8_t a;
	
	cli();		// WatchDog disabled AT ALL TIMES !
	init();
	loadParams();
	sei();
	
	BLINK;
	BLINK;
	
	while(1) {
		if(received) {		// Signal received byte
			received = 0;
			BLINK;
		}
		
		// Get addr
		a = 0x00;
		if(!ADDR0) a += 1;
		if(!ADDR1) a += 2;
		if(!ADDR2) a += 4;
		addr = a;
		
		_delay_ms(10);
	}
	
	return 0;
}