project moved from https://github.com/tmeissner/avr/planefinder to https://github.com/tmeissner/planefinder

makefile

@@ -0,0 +1,23 @@
+#AVR-GCC Makefile
+PROJECT = planefinder
+SOURCES = src/main.c
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+MMCU = attiny13
+
+DUMMY_BINARY:=$(shell mkdir -p binary)
+
+CFLAGS = -mmcu=$(MMCU) -Wall -Os -std=gnu99
+
+binary/$(PROJECT).hex: binary/$(PROJECT).out
+	$(OBJCOPY) -j .text -O ihex binary/$(PROJECT).out binary/$(PROJECT).hex
+
+binary/$(PROJECT).out: $(SOURCES)
+	$(CC) $(CFLAGS) -I./ -o binary/$(PROJECT).out $(SOURCES)
+
+program: binary/$(PROJECT).hex
+	avrdude -p t13 -c usbasp -e -U flash:w:binary/$(PROJECT).hex
+
+clean:
+	rm -f binary/$(PROJECT).out
+	rm -f binary/$(PROJECT).hex

src/main.c

@@ -0,0 +1,104 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <stdint.h>
+#define F_CPU 9600000UL
+
+volatile uint8_t beep_disable = 0;
+volatile uint8_t beep_enable  = 0;
+
+static void set_wait_timer (void);
+void set_beep_timer (uint8_t outport);
+
+
+// main function
+int main (void)
+{
+
+  DDRB = (1<<DDB1) | (1<<DDB0);  // set PB0 & PB1 to output
+
+  set_sleep_mode(SLEEP_MODE_IDLE);  // set sleep mode
+
+  set_beep_timer(0);  // generate signal with beeper frequency
+
+  while (beep_disable == 0) {} // wait for expired beep counter
+
+  set_wait_timer();  // start timer to wait 600 secs
+
+  // wait for expired wait counter
+  while (beep_enable == 0) {
+    sleep_mode();  // goto sleep until next interrupt
+  }
+
+  // endless loop until switch-off
+  while(1) {
+    set_beep_timer(0);  // generate signal with beeper frequency
+    while (beep_disable == 0) {}
+    set_beep_timer(1);  // generate signal with beeper frequency
+    while (beep_disable == 0) {}
+  }
+
+  return 0;
+}
+
+
+// routine to set timer0 for waiting until beep
+static void set_wait_timer (void)
+{
+  cli();
+  TCCR0A = 0x00;  // set timer0 to normal mode 
+  TCCR0B = (1<<CS02) | (1<<CS00);  // set timer0 prescaler to 1024
+  TIMSK0 = (1<<TOIE0);  // interrupt enable for timer0 overflow
+  sei();
+  return;
+}
+
+
+// routine to set timer0 for to generate frequency for beeper
+void set_beep_timer (uint8_t outport)
+{
+  cli();
+  if (outport == 0) {
+    TCCR0A = (1<<COM0A0) | (1<<WGM01);  // toggle OC0A on compare match , ctc mode
+  } else {
+    TCCR0A = (1<<COM0B0) | (1<<WGM01);  // toggle OC0B on compare match , ctc mode
+  }
+  TCCR0B = (1<<CS00);    // set timer0 prescaler to 1 (no prescaling)
+  OCR0A  = 0xE7;         // set output compare register a
+  TIMSK0 = (1<<OCIE0A);  // interrupt enable for timer0 compare match a
+  sei();
+  return;
+}
+
+
+// interrupt routine for timer0 output compare match a
+ISR(TIM0_COMPA_vect)
+{
+  static uint16_t overflow = 0;
+  // after count up to 1 second
+  // deactivate beeper & disable timer0 output compare match a interrupt
+  if (overflow <= 10920) {
+    beep_disable = 0;
+    overflow ++;
+  } else {
+    TIMSK0       &= ~(1<<OCIE0A);  // interrupt disable for timer0 compare match a
+    beep_disable = 1;
+    overflow     = 0;
+  }
+}
+
+
+// interrupt routine for timer0 overflow
+ISR(TIM0_OVF_vect)
+{
+  static uint16_t overflow = 0;
+  // after count up to 1200 seconds
+  // activate beeper & disable timer0 overflow interrupt
+  if (overflow <= 6000) {  // for test: 30 ca. 6 sek.
+    overflow ++;
+  } else {
+    beep_enable = 1;
+    TIMSK0      &= ~(1<<TOIE0);  // interrupt disable for timer0 overflow
+  }
+}
+