pentabug/firmware/lib/bughal.c

#include <inttypes.h>
#include <avr/io.h>
#include "bughal.h"
#include "util.h" //for timer
/* Hardware abstraction layer for Pentabug hardware */

/*
 * initialize LEDs on C0-C3
 */

static uint8_t oldinput; // button readings from last poll cycle
static uint8_t curinput; // button readings from current poll cycle

//each switch has its own state machine
static uint8_t btnstates[BTN_BUTTONS]; //array for current button states
static uint8_t btncounters[BTN_BUTTONS]; //individual counter for button state machine
static timer_t btntimers[BTN_BUTTONS]; //individiual timer for for button state machine

void init_leds(void) {
	//enable LED channels as output
	DDRC |= (1 << PORTC0) | (1 << PORTC1) | (1 << PORTC2) | (1 << PORTC3);
	// both LEDs off
	PORTC &= ~((1 << PORTC0) | (1 << PORTC1) | (1 << PORTC2) | (1 << PORTC3));
	return;
}

inline void led_on(int leds) {
	PORTC |= leds;
}

inline void led_off(int leds) {
	PORTC &= ~leds;
}

void init_buzzr(void) {
	// its on B2 and C5
	DDRC |= (1 << PORTC5);
	DDRB |= (1 << PORTB2);
	// switch it off
	buzzr_off();
	return;
}

void init_mic(void) {
	// buzzer is on B2 and C5, for reasons
	// ... we use it as microphone
	DDRC &= ~(1 << PORTC5); // switch C5 to input
	DDRB |= (1 << PORTB2); // B2 as output
	PORTB &= ~(1 << PORTB2); //and to GND	
	ADMUX = (1 << REFS1) | (1 << REFS0); // use internal 1.1V as reference
	ADCSRA = (1 << ADPS1) | (1 << ADPS0); // prescaler F_CPU/8
	ADCSRA |= (1 << ADEN) | (1 << ADATE); // ADC enable - turn it on in free running mode
	ADCSRB &= (1 << ACME); //leave only ACME as it is (others zerp for free running)
	ADMUX = (ADMUX & ~(0x1F)) | 5; // select channel 5
	ADCSRA |= (1 << ADSC); // start conversion
	uint16_t __attribute__((unused)) dummy = ADCW; //read once
	return;
}

void buzzr_up(void) {
	// one pin Vcc, other GND
	PORTC &= ~(1 << PORTC5);
	PORTB |= (1 << PORTB2);
	return;
}
;

void buzzr_down(void) {
	// one pin GND,other pin Vcc
	PORTC |= (1 << PORTC5);
	PORTB &= ~(1 << PORTB2);
}

inline void buzzr_off(void) {
	// both pins to GND
	PORTC &= ~(1 << PORTC5);
	PORTB &= ~(1 << PORTB2);
}


void buzzr_inv(void) {
	// read and invert pin settings, make the piezo flip polarity
	PORTC ^= (1 << PORTC5);
	PORTB ^= (1 << PORTB2);
}


void init_switch(void) {
	// init switch 1 and switch 2
	DDRD &= ~((1 << PORTD1) | (1 << PORTD0)); // D0 and D1 as input
	PORTD |= (1 << PORTD1) | (1 << PORTD0); // pull-ups FTW
	// set predefined button states
	oldinput = 0;
	curinput = 0;
	// initialize the state machine of each button
	for (uint8_t i = 0; i < BTN_BUTTONS; i++) {
		btnstates[i] = BTNST_NTRL; //init button states
		btncounters[i] = 0; //init button counters
		timer_set(&btntimers[i], 0x05); //50ms - init button timers
	};
	return;
}


bool switch_l(void) {
	return !(PIND & 0b00000001);
}


bool switch_r(void) {
	return !(PIND & 0b00000010);
}


void init_motor(void) {
	/* vibration motor on B1, initially off: */
	DDRB |= (1 << PORTB1);
	PORTB &= ~(1 << PORTB1);
	return;
}

void set_motor(int val) {
	if (val == MOTOR_ON) {
		PORTB |= 0x02;
	} else {
		PORTB &= ~(0x02);
	}
	return;
}

// reset button to neutral state
void button_clear(uint8_t button) {
	btnstates[button] = BTNST_NTRL;
}

void stateswitch(uint8_t i) {
	switch (btnstates[i]) {
	case BTNST_NTRL: //NEUTRAL
		if (curinput & (1 << i)) { //button down
			btncounters[i] = 0;
			btnstates[i] = BTNST_DBNC;
		}
		break;
	case BTNST_DBNC: //intermediate state, check if button is still pressed to debounce
		btnstates[i] = (curinput & (1 << i)) ? BTNST_SDN : BTNST_NTRL;
		(btncounters[i])++;
		break;
	case BTNST_SDN:
		if (curinput & (1 << i)) {
			btncounters[i]++;
			if (btncounters[i] > BTN_T_LONGFACT) { //500ms held
				btnstates[i] = BTNST_LDN;
			}
		} else { //button was released
			btnstates[i] = BTNST_SUP;
			//signal shortclick
		}
		break;
	case BTNST_LDN:
		if (!(curinput & (1 << i))) {
			//button was released
			btnstates[i] = BTNST_LUP; //signal longpress
		}
		break;
	case BTNST_SUP:
		if ((curinput & (1 << i))) {
			//button was pressed again or is bouncing after release
			btnstates[i] = BTNST_SUPDBNC; //going in special debounce
			btncounters[i] = 0;
		}
		break;
	case BTNST_LUP:
		if ((curinput & (1 << i))) {
			//button was pressed again or is bouncing after release
			btnstates[i] = BTNST_LUPDBNC; //going in special debounce
			btncounters[i] = 0;
		}
		break;
	case BTNST_SUPDBNC:
		if ((curinput & (1 << i))) {
			//button is still pressed --> going to shortpress
			btncounters[i]++;
			btnstates[i] = BTNST_SDN; //starting over from short pressed
		} else {
			btnstates[i] = BTNST_SUP; //nope, it was bouncing, back to old state
		}
		break;
	case BTNST_LUPDBNC:
		if ((curinput & (1 << i))) {
			//button is still pressed --> going to shortpress
			btncounters[i]++;
			btnstates[i] = BTNST_SDN; //starting over from short pressed
		} else {
			btnstates[i] = BTNST_LUP; //nope, it was bouncing, back to old state
		}
		break;
	default: //curently catches nothing
		// do nothing yet
		;
		break;
	}; //end switch
	timer_set(&btntimers[i], BTN_T_DEBOUNCE);
}

void button_poll() {
	curinput = ~(PIND & 0b00000011);
	for (uint8_t i = 0; i < BTN_BUTTONS; i++) {
		if (timer_expired(&btntimers[i])) {
			stateswitch(i);
		} //end if timer expired
	} //end for
	oldinput = curinput;
	return;
}

bool btn_state(uint8_t btnstate, uint8_t btn) {
	return (btnstates[btn] == btnstate);
}