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#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <avr/sleep.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include "barometer.h"
#include "display.h"
#include "util.h"
#ifdef WDT_DISABLE
# warning "WDT disabled in this build"
# define WDT_SETUP_MAYBE(x)
# define WDT_PAT_MAYBE()
#else
# define WDT_SETUP_MAYBE(x) do{wdt_enable(x);}while(0)
# define WDT_PAT_MAYBE() do{wdt_reset();}while(0)
#endif
/* ISR for collecting and displaying pressure, altitude data etc */
ISR(TIMER1_COMPA_vect)
{
PORTD ^= 1 << 5;
int tcnt1_start = TCNT1;
static volatile float setting = 1040.21; /* FIXME volatile for gdb hacks */
static float last_height = 0;
float pressure = 0;
float height_m = 0;
float rate_m_s;
char rate_sym;
pressure = barometer_read();
height_m = pressure_to_metres_asl(pressure, setting);
rate_m_s = height_m - last_height;
last_height = height_m;
if (rate_m_s < 0) {
rate_sym = C_DESC;
} else if (rate_m_s == 0) {
rate_sym = C_IDLE;
} else {
rate_sym = C_ASC;
}
char line[LCD_WIDTH+1];
/* line 1 */
int alt_m_int;
float alt_m_float;
split_float(height_m, &alt_m_int, &alt_m_float);
snprintf(line, sizeof(line), "%d.%d m %c%d m/s", alt_m_int, (int)(round(alt_m_float*10)), rate_sym, abs(rate_m_s));
blank_to_eol(line, sizeof(line));
display_set_cursor(0, 0);
display_write(line);
/* line 2 */
int pressure_hpa_int;
float pressure_hpa_float;
split_float(pressure, &pressure_hpa_int, &pressure_hpa_float);
snprintf(line, sizeof(line), "%d.%d hPa", pressure_hpa_int, (int)(round(pressure_hpa_float*100)));
blank_to_eol(line, sizeof(line));
display_set_cursor(0, 1);
display_write(line);
/* line 3 */
int setting_hpa_int;
float setting_hpa_float;
split_float(setting, &setting_hpa_int, &setting_hpa_float);
snprintf(line, sizeof(line), "SET %d.%d hPa", setting_hpa_int, (int)(round(setting_hpa_float*100)));
blank_to_eol(line, sizeof(line));
display_set_cursor(0, 2);
display_write(line);
int tcnt1_end = TCNT1;
/* line 4 */
snprintf(line, sizeof(line), "TCNT1 delta %u", tcnt1_end - tcnt1_start);
blank_to_eol(line, sizeof(line));
display_set_cursor(0, 3);
display_write(line);
WDT_PAT_MAYBE();
}
int main(void)
{
/* Initialise display before enabling interrupts */
display_init();
display_clear();
DDRB |= 1 << 0;
DDRD |= 1 << 5;
/* Initialise timers for /1024 prescaler, 1 Hz comparator val */
TCCR1B |= (1 << CS10) | (1 << CS12) | (1 << WGM12);
TIMSK1 |= (1 << OCIE1A);
OCR1A = F_CPU / 1024;
#ifdef USBCON
/* Disable USB controller if one is present - this spams (latches?) USB_GEN
* interrupt which we're not handling for now */
USBCON &= ~(1 << USBE);
#endif
/* main body should take no longer than 1 second to run */
WDT_SETUP_MAYBE(WDTO_2S);
sei();
while(1) {
set_sleep_mode(SLEEP_MODE_IDLE);
sleep_mode();
}
}
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