templog: main.c comparison

comparison main.c @ 420:d386bbab85cf

try and take account of the fridge temperature too

author	Matt Johnston <matt@ucc.asn.au>
date	Wed, 10 Oct 2012 21:04:13 +0800
parents	b73ea78317dc
children	30c2c3341a4a

comparison

equal deleted inserted replaced

-:a60a015732ea
+:d386bbab85cf
 // - measurement interval
 // - transmit interval
 // - bluetooth params
 // - number of sensors (and range?)
+#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))
+#define MAX(X,Y) ((X) > (Y) ? (X) : (Y))
 // TICK should be 8 or less (8 untested). all timers need
 // to be a multiple.
 #define TICK 6
 // we have 1024 prescaler, 32768 crystal.
 #define SLEEP_COMPARE (32*TICK-1)
 #define VALUE_NOSENSOR 0x07D0 // 125 degrees
 #define VALUE_BROKEN 0x07D1 // 125.0625
+#define FRIDGE_AIR_MIN_RANGE 3
+#define FRIDGE_AIR_MAX_RANGE 3
+#define OVERSHOOT_SCALE 1
 #define BAUD 19200
 #define UBRR ((F_CPU)/8/(BAUD)-1)
 #define PORT_LED PORTC
 #define DDR_LED DDRC
 #define DDR_FRIDGE DDRD
 #define PIN_FRIDGE PD6
 // total amount of 16bit values available for measurements.
 // adjust emperically, be sure to allow enough stack space too
-#define TOTAL_MEASUREMENTS 840
+#define TOTAL_MEASUREMENTS 800
 // each sensor slot uses 8 bytes
 #define MAX_SENSORS 6
 // fixed at 8, have a shorter name
 static uint16_t measure_wake = 61; // not a divisor of comms_wake
 static uint16_t comms_wake = 600;
 static uint8_t wake_secs = 30;
 // decidegrees
 static int16_t fridge_setpoint = 180; // 18.0ºC
-static int16_t fridge_difference = 5; // 0.5ºC
+static int16_t fridge_difference = 3; // 0.3ºC
 static uint16_t fridge_delay = 600; // seconds
 // ---- Atomic guards required accessing these variables
+// clock_epoch in seconds
 static uint32_t clock_epoch;
 static uint16_t comms_count;
 static uint16_t measure_count;
 // ---- End atomic guards required
 static uint8_t sensor_id[MAX_SENSORS][ID_LEN];
 static int16_t last_fridge = DS18X20_INVALID_DECICELSIUS;
 static int16_t last_wort = DS18X20_INVALID_DECICELSIUS;
 static struct epoch_ticks fridge_off_clock = {0};
+static struct epoch_ticks fridge_on_clock = {0};
 int uart_putchar(char c, FILE *stream);
 static void long_delay(int ms);
 static void blink();
 static uint16_t adc_vcc();
 {
 printf_P(PSTR("Bad fridge value %f\n"), new_f);
 return;
 }
+int16_t old_setpoint = fridge_setpoint;
 fridge_setpoint = new_f * 10;
 bool written = set_initial_eeprom();
 if (!written)
 {
-ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+if (old_setpoint != fridge_setpoint)
 {
-eeprom_write(fridge_setpoint, fridge_setpoint);
+ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
-}
+{
-}
+eeprom_write(fridge_setpoint, fridge_setpoint);
-printf_P(PSTR("new fridge %.1fº\n"), fridge_setpoint / 10.0f);
+}
+}
+}
+printf_P(PSTR("old fridge %.1fº new fridge %.1fº\n"),
+old_setpoint / 10.0f, fridge_setpoint / 10.0f);
 }
 static void
 cmd_set_fridge_difference(char *params)
 {
 static void
 do_fridge()
 {
 struct epoch_ticks now;
 get_epoch_ticks(&now);
-uint16_t delay_delta = now.ticks - fridge_off_clock.ticks;
+uint16_t off_time = now.ticks - fridge_off_clock.ticks;
-if (delay_delta < fridge_delay)
+bool wort_valid = last_wort != DS18X20_INVALID_DECICELSIUS;
+bool fridge_valid = last_fridge != DS18X20_INVALID_DECICELSIUS;
+int16_t wort_max = fridge_setpoint + fridge_difference;
+int16_t wort_min = fridge_setpoint;
+// the fridge min only applies when the wort is in the desired range.
+int16_t fridge_min = fridge_setpoint - FRIDGE_AIR_MIN_RANGE;
+int16_t fridge_max = fridge_setpoint + FRIDGE_AIR_MAX_RANGE;
+uint8_t fridge_on = PORT_FRIDGE & _BV(PIN_FRIDGE);
+printf_P(PSTR("last_wort %hd (%hd, %hd), last_fridge %hd (%hd, %hd), setpoint %hd, diff %hd, fridge_on %d\n"),
+last_wort, wort_min, wort_max,
+fridge_setpoint, fridge_min, fridge_max,
+fridge_difference, fridge_on);
+if (off_time < fridge_delay)
 {
 printf_P(PSTR("waiting for fridge delay current %hu, wait %hu\n"),
-delay_delta, fridge_delay);
+off_time, fridge_delay);
 return;
 }
-if (last_wort == DS18X20_INVALID_DECICELSIUS)
-{
-// can't really do much sensible.... alert perhaps?
-printf_P(PSTR("Bad last wort!\n"));
-need_comms = 1;
-return;
-}
-int16_t wort_delta = last_wort - fridge_setpoint;
-uint8_t fridge_on = PORT_FRIDGE & _BV(PIN_FRIDGE);
-printf_P(PSTR("last_wort %hd, setpoint %hd, delta %hd, fridge_on %d\n"),
-last_wort, fridge_setpoint, wort_delta, fridge_on);
 if (fridge_on)
 {
-if (last_wort <= fridge_setpoint)
+bool turn_off = false;
+uint16_t on_time = now.ticks - fridge_on_clock.ticks;
+// *10 for decicelcius
+uint16_t overshoot = OVERSHOOT_SCALE * 10.0f * MAX(3600, on_time) / 3600.0;
+// wort has cooled enough. will probably cool a bit more by itself
+if (wort_valid && (last_wort-overshoot) <= fridge_setpoint)
+{
+printf_P("wort has cooled enough, overshoot %hu\n", overshoot);
+turn_off = true;
+}
+// fridge is much cooler than wort
+if ((last_wort < wort_max || !wort_valid) &&
+fridge_valid && last_fridge < fridge_min)
+{
+printf_P("fridge is too cold\n");
+turn_off = true;
+}
+if (turn_off)
 {
 // too cold, turn off
 printf_P(PSTR("Turning fridge off\n"));
 PORT_FRIDGE &= ~_BV(PIN_FRIDGE);
 fridge_off_clock = now;
 }
 }
 else
 {
-if (wort_delta > fridge_difference)
+bool turn_on = false;
+if (wort_valid && last_wort >= wort_max)
+{
+printf_P("wort is too hot\n");
+turn_on = true;
+}
+if ((last_wort > wort_min || !wort_valid) &&
+(fridge_valid && last_fridge > fridge_setpoint))
+{
+printf_P("fridge is too hot\n");
+turn_on = true;
+}
+if (turn_on)
 {
 // too hot, turn on
 printf_P(PSTR("Turning fridge on\n"));
 PORT_FRIDGE |= _BV(PIN_FRIDGE);
+fridge_on_clock = now;
 }
 }
 }
 static void
 }
 set_measurement(s, n_measurements, reading);
 if (memcmp(sensor_id[s], fridge_id, sizeof(fridge_id)) == 0)
 {
-last_fridge = ds18b20_raw16_to_decicelsius(reading);;
+last_fridge = ds18b20_raw16_to_decicelsius(reading);
 }
 if (memcmp(sensor_id[s], wort_id, sizeof(wort_id)) == 0)
 {
-last_wort = ds18b20_raw16_to_decicelsius(reading);;
+last_wort = ds18b20_raw16_to_decicelsius(reading);
 }
 }
 n_measurements++;
 }

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comparison main.c @ 420:d386bbab85cf