//https://www.instructables.com/ATtiny85-Interrupt-Barebones-Example/

/*
 *  ATTiny85 simple interrupt handling example
 *  
 *  Pieced together from various places, but mostly from here:
 *  https://arduino.stackexchange.com/questions/3929/attiny85-interrupt-id-vs-pin-when-programming-with-arduino
 *  
 *  Contributors:
 *    GisMofx <https://arduino.stackexchange.com/users/11075/gismofx>
 *    Aaron S. Crandall <[email protected]> - 2019
 *    
 *  This code reacts to a Pin Change Interrupt on PB1 which switches an LED on and off on PB4.
 *  This is an "external interrupt" in some documents and other platforms
 *  
 *  To wire this example;
 *    Connect a switch that connects PB1 (pin 6) of the ATtiny85 to ground when pressed
 *    Connect an LED with:
 *      positive terminal (anode - the long lead) to PB4 (pin 3)
 *      negative terminal (cathode - the short lead) to a resistor (300 to 2k ohms all work)
 *    Connect resistor between LED and ground bus
 *    Connect ATtiny85 pin 8 (vcc) to +5 volts
 *    Connect ATtiny85 pin 4 (ground) to ground
 *    
 *    Shared under the Creative Commons Attribution 4.0 International license
 *    https://creativecommons.org/licenses/by/4.0/
 *    
 */

// Requires headers for AVR defines and ISR function
#include <avr/io.h>
#include <avr/interrupt.h>

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





// Define pins for switch the LED, plus the chosen interrupt for reacting to
#define INTERRUPT_PIN PCINT2 // This is PB2 V_DET 

#define BUZZ PB0          // Buzz
#define DATA_SW PB1     // Data Blue Led    //PB1
#define V_DET PB2       // Opto couple slide sw  ADC1 
#define I_DET PB3       // port ACS712 I sensor  ADC2
#define CHRG_SW PB4   //  Chrg Red Led //SDA
#define RST PB5       //  GRN SW RST 

#define F_CPU 16000000UL
#define ADC_CH_2 A3
#define ADC_CH_3 A2

/*
 * Alias for the ISR: "PCINT_VECTOR" (Note: There is only one PCINT ISR. 
 * PCINT0 in the name for the ISR was confusing to me at first, 
 * hence the Alias, but it's how the datasheet refers to it)
 */
#define PCINT_VECTOR PCINT0_vect
// FYI: Variables used within ISR must be declared Volatile.
// static volatile byte LEDState; 

// ADC SUPPORT REG
uint8_t temp = 0;
uint16_t u=0, adcValue=0;




// The setup function runs only once when the ALU boots
void setup() {
    pinMode(CHRG_SW, OUTPUT); 
    pinMode(BUZZ, OUTPUT);        // Set our chosen CHRG RELAY SW
    pinMode(DATA_SW, OUTPUT);         // Set our chosen DATA RELAY SW
    pinMode(I_DET,INPUT);
    pinMode(V_DET,INPUT);
    pinMode(V_DET, INPUT_PULLUP); 
    MCUCR &= (1 << PUD); //disabling Pull Up Disable i.e, enabling pullups, otherwise EXT pull up resistors cannot be enabled in pins

    uint16_t ADC_VAl = 0;
    char ADC_VAL_Char[5];


    analogReference(INTERNAL2V56);
    // IO configuration
	DDRB &= ~(1 << ADC_CH_2) & ~(1 << ADC_CH_3); //configuring as input assign to ADC2 & 3
	PORTB |= (1 << ADC_CH_2) | (1 << ADC_CH_3); //  writing 1 to an input pin activates pullup-resistor
	DIDR0 |= (1 << ADC_CH_2) | (1 << ADC_CH_3); // disable digital buffer in analog pins to save power

    digitalWrite(BUZZ, HIGH);      // Blink to show it's booting up and your LED is wired correctly
    delay(500);
    digitalWrite(BUZZ, LOW);
    delay(500);

    // Code here is the key piece of configuring and enabling the interrupt 
    cli();                            // Disable interrupts during setup
 
    PCMSK |= (1 << INTERRUPT_PIN);    // Enable interrupt handler (ISR) for our chosen interrupt pin (PCINT1/PB1/pin 6)

    //GIMSK |= (1 << PCIE);             // Enable PCINT interrupt in the general interrupt mask
    GIMSK |= (1 << PCIE);
    MCUCR |= (0 << ISC01);
    MCUCR |= (1 << ISC00); 

    pinMode(V_DET, INPUT_PULLUP);   // Set our interrupt pin as input with a pullup to keep it stable

    sei();                            //last line of setup - enable interrupts after setup


  }


//*************************************************
// // SOURCE : https://controllerstech.com/avr-tutorial-5-how-to-use-adc/

uint16_t ADC_Convert (void)
{
	ADCSRA |= 1<<ADSC;  // start conversion
	while ((ADCSRA&(1<<ADSC)) == 1){}  // wait for the conversion to finish
	uint8_t adcl = ADCL; // read ADCL register
	uint8_t adch = ADCH; // read ADCH Register
	uint16_t val = ((adch<<8)|adcl)&0x3FF;  // combine into single 10 bit value, 0x3FF-> 0b11 1111 1111	 
	return val;
}
//*********************************************


void loop() {
//*********************************

/*/ SOURCE : https://controllerstech.com/avr-tutorial-5-how-to-use-adc/
  uart_init();
    ADC_init();
    ADC_START_READ()
    {
    	ADC_VAl = ADC_Convert();
	sprintf(ADC_VAL_Char, "%u\n", ADC_VAl);
	uart_str(ADC_VAL_Char);
	_delay_ms(200);
    }

//***************************************/
  // Put any general processing code in the main loop
  // Be aware - if the INT_PIN changes state, the loop will be suspended while the ISR runs to completion
}


// This is the interrupt handler called when there is any change on the INT_PIN
// ISR is defined in the headers - the ATtiny85 only has one handler
ISR(PCINT_VECTOR)
{
   cli();
  //IF LOW then CHRG  PWR ON
  if( digitalRead(V_DET) == LOW )
   {
    digitalWrite(BUZZ, LOW);
    digitalWrite(DATA_SW,LOW); 
    digitalWrite(CHRG_SW,LOW);
    delayMicroseconds(1000);
  }
  //TAB VCC HIGH means  THEN CHRG DOWN OTG MODE
  else    
  { 
      
    digitalWrite(BUZZ, HIGH);
    digitalWrite(DATA_SW,HIGH); 
    digitalWrite(CHRG_SW,HIGH);
    delayMicroseconds(1000);
   
  }
  sei();

}  // end of isr

//ADC INTR VECTOR SERVICE
// SOURCE : 
ISR(ADC_vect) 
{
	adcValue = ADCW;
	//adcValue = (ADCH<<8)|ADCL;
	if (adcValue==1023){
		int i=1;
		while(i++<20){
			PORTB|= 1<<PB1;
			_delay_ms(100);
			PORTB&= ~(1<<PB1);
			_delay_ms(100);
		}
 
	}else{
		PORTB|= 1<<PB1;
	} // END ADC VECT INTR

} //end isr adc vect