Initial commit

Author: Kixunil

Makefile

@@ -0,0 +1,31 @@
+#default values
+CONFIG=./avrdude.conf
+PORT=/dev/ttyUSB0
+BAUDRATE=19200
+PROCESSOR=attiny13
+PROGRAMMER=stk500v1
+VERBOSE=
+CC=avr-gcc
+
+all: receiver.hex sender.hex
+	@echo "Compiled. Use make flash-sender or make flash-receiver to program the microcontroler"
+
+%.hex: %.elf
+	avr-objcopy -j .text -j .data -O ihex $< $@
+
+%.elf: %.c
+	$(CC) -W -Wall -mmcu=$(PROCESSOR) -Os -o $@ $<
+
+%.s: %.c
+	$(CC) -W -Wall -mmcu=$(PROCESSOR) -S -Os -o $@ $<
+
+flash-%: %.hex
+	avrdude $(VERBOSE) -C $(CONFIG) -P $(PORT) -b $(BAUDRATE) -p $(PROCESSOR) -c $(PROGRAMMER) -U flash:w:$<:i
+
+read-fuses:
+	avrdude $(VERBOSE) -C $(CONFIG) -P $(PORT) -b $(BAUDRATE) -p $(PROCESSOR) -c $(PROGRAMMER) -U lfuse:r:-:h -U hfuse:r:-:h
+
+read-eeprom:
+	avrdude $(VERBOSE) -C $(CONFIG) -P $(PORT) -b $(BAUDRATE) -p $(PROCESSOR) -c $(PROGRAMMER) -U eeprom:r:-:h
+
+.PHONY: all flash flash-% read-fuses read-eeprom

README.md

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+IR controlled light
+===================
+
+This project is simple pair of IR sender/receiver based on ATTiny 13, which allows to control two lights remotely using infrared radiation.
+
+Author
+------
+
+Martin Habovštiak <[email protected]>

common.h

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+#define RED_LED		0b00000100		// PB3 (physical pin 2); OUTPUT
+#define GREEN_LED	0b00000010		// PB2 (physical pin 7); OUTPUT
+
+// Our address is answer to The question of life, universe and everything
+#define DEVICE_ADDRESS 42
+

receiver.c

@@ -0,0 +1,222 @@
+#define F_CPU 1000000UL                                    /* Clock Frequency = 1Mhz */
+
+#include <inttypes.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/interrupt.h> 
+#include <avr/sleep.h>
+#include <avr/eeprom.h> // For debugging
+
+#include "common.h"
+
+#define UCSRB UCSR0B
+
+#define RED_BUTTON	0b00010000		// PB4 (physical pin 3); INPUT;
+#define GREEN_BUTTON	0b00001000		// PB1 (physical pin 6); INPUT;
+#define IR_INPUT	0b00000001		// PB0 (physical pin 5; PCINT0); INPUT;
+						// TSOP 4838 is connected here
+#define INTERNAL_PULLUPS GREEN_BUTTON | RED_BUTTON
+#define ALLOWED_BITS (RED_LED | GREEN_LED) // IR controllers are allowed to change LEDs
+
+#define TIMER_SPEED ((1<<CS02) | (1<<CS00)) // 1/256 MHz
+#define BASE_LEN 6 // Length of shortest pulse in clock ticks
+#define TOLERANCE 1 / 3
+
+//#define DEBUG_STATES
+
+#ifdef DEBUG_PULSE_LENGTHS
+	#define DEBUG
+#endif
+
+#ifdef DEBUG_STATES
+	#define DEBUG
+#endif
+
+volatile char run;
+volatile char firsttime;
+volatile char bit_state = 0;
+volatile char byte_state = 0;
+volatile char recvd_data = 0; // Received bits
+volatile char recvd_bit = 0;  // On which bit position we are
+volatile int last_pulse_length;
+volatile uint8_t *mem_pos = 0;
+
+#ifdef DEBUG
+void append_byte(char byte) {
+	if(mem_pos < (uint8_t *)64) {
+		eeprom_write_byte((uint8_t *)mem_pos, byte);
+		++mem_pos;
+	}
+}
+#endif
+
+signed char rangecmp(int time, int length) {
+	if(time < length * BASE_LEN - BASE_LEN * TOLERANCE) return -1;
+	if(time > length * BASE_LEN + BASE_LEN * TOLERANCE) return 1;
+	return 0;
+}
+
+void process_byte() {
+	// Byte states:
+	// 0 - waiting for device address
+	// 1 - our device address set
+	// 2 - ignore bytes until reset
+	switch(byte_state) {
+		case 0:
+			if(recvd_data == DEVICE_ADDRESS) {
+				byte_state = 1;
+			} else {
+				byte_state = 0;
+			}
+			break;
+		case 1:
+			PORTB = (PORTB & ~ALLOWED_BITS) | (recvd_data & ALLOWED_BITS); // Set outputs
+			++byte_state;
+			break;
+	}
+}
+
+void reset_bit_state() {
+	recvd_data = 0;
+	recvd_bit = 0;
+	bit_state = 0;
+	byte_state = 0;
+}
+
+void read_bit(int ticks) {
+	signed char r = rangecmp(ticks, 1);
+	signed char r2 = rangecmp(ticks, 2);
+	if(r < 0 || r2 > 0) { // Protocol error - reset state
+		reset_bit_state();
+	}
+
+	if(!(PINB & IR_INPUT)) { // There was space
+		if(!r && !rangecmp(last_pulse_length, 2)) { // Correct signal of bit "1"
+			recvd_data <<= 1;
+			recvd_data |= 1;
+			++recvd_bit;
+		} else if(!r2 && !rangecmp(last_pulse_length, 1)) {// Correct signal of bit "0"
+			recvd_data <<= 1;
+			++recvd_bit;
+		} else { // error
+			reset_bit_state();
+		}
+		if(recvd_bit == 8) { // We've got whole byte
+			process_byte();
+			// NOT doing reset_bit_state, because there may come new data
+			recvd_data = 0;
+			recvd_bit = 0;
+		}
+
+	} else { // There was signal
+		last_pulse_length = ticks;
+	}
+}
+
+ISR(PCINT0_vect) {
+	// Test if buttons are hold down
+	if(!(PINB & GREEN_BUTTON)) {
+		PORTB = (PORTB & ~RED_LED) | GREEN_LED;
+		return;
+	}
+	if(!(PINB & RED_BUTTON)) {
+		PORTB = (PORTB & ~GREEN_LED) | RED_LED;
+		return;
+	}
+	int ticks = TCNT0; // Savetimer value
+	TCNT0 = 0;	    // Reset timer
+	if(!(TCCR0B & TIMER_SPEED)) {
+		TCCR0B |= TIMER_SPEED; // Start timer (in case it's not running)
+		return;
+	}
+
+#ifdef DEBUG_PULSE_LENGTHS
+	if(mem_pos < (uint8_t *)64) {
+		eeprom_write_byte((uint8_t *)mem_pos, ticks);
+		++mem_pos;
+#ifdef VISUAL_DEBUG
+		PORTB |= GREEN_LED;
+	} else PORTB &= ~GREEN_LED;
+#else
+	}
+#endif
+#endif
+
+	switch(bit_state) {
+		case 0:
+			if((PINB & IR_INPUT) && !rangecmp(ticks, 3)) ++bit_state;
+#ifdef DEBUG_STATES
+			append_byte(bit_state);
+#endif
+			break;
+		case 1:
+			if(!(PINB & IR_INPUT) && !rangecmp(ticks, 3))
+				++bit_state;
+			else
+				bit_state = 0;
+#ifdef DEBUG_STATES
+			append_byte(bit_state);
+#endif
+			break;
+		case 2:
+			read_bit(ticks);
+#ifdef DEBUG_STATES
+			append_byte(byte_state);
+			append_byte(recvd_bit);
+			append_byte(recvd_data);
+#endif
+			break;
+	}
+#ifdef VISUAL_DEBUG
+	PORTB = (PORTB & ~RED_LED) | ((~PINB & IR_INPUT) << 3);
+#endif
+}
+
+ISR(TIM0_OVF_vect) {
+	TCCR0B &= ~((1 << CS00) | (1 << CS01) | (1 << CS02)); // Stop timer
+	TCNT0 = 0; // Too long - reset timer
+
+#ifdef DEBUG_PULSE_LENGTHS
+	if(mem_pos < (uint8_t *)64) { // Log overflow
+		eeprom_write_byte((uint8_t *)mem_pos, 0);
+		++mem_pos;
+	}
+#endif
+
+}
+
+int main() {
+	// ================== IO Setup =================
+
+	DDRB = GREEN_LED | RED_LED;  // Set IO pins. GREEN_LED and RED_LED are outputs
+	PORTB = INTERNAL_PULLUPS; // Init internal pullups
+
+	PORTB |= GREEN_LED | RED_LED;
+	_delay_ms(250);
+	PORTB &= ~(GREEN_LED | RED_LED);
+
+	// ================ Timer Setup ================
+
+	TCCR0A = 0; // Normal mode
+	//TCCR0B |= (1 << CS00); // Configure prescaler to 1MHz (one tick == one microsecond)
+	TIMSK0 |= (1 << TOIE0); // Enable overflow interrupt
+	TCNT0 = 0;
+
+	// ============== Interrupt Setup ==============
+	
+	MCUCR |= (1<<ISC00); // PCINT0 is triggered on any edge
+	PCMSK = IR_INPUT | RED_BUTTON | GREEN_BUTTON; // Enable interrupt on IR_INPUT
+	GIMSK |= (1<<PCIE); // enable pin change interrupts
+
+	//Enable global interrupts
+	sei();
+
+	run = 1;
+	while (run) {
+	}
+
+	sleep_enable();
+	sleep_cpu();
+
+	return 0;
+}