schedule.h File Reference

#include <OPEnS_RTC.h>
#include <LowPower.h>
#include "pinout.h"
#include "measure.h"
#include "debug.h"

Go to the source code of this file.

Functions
void	alarmISR (void)
	Interrupt handler for RTC alarm. More...
void	feather_sleep (void)
	Maximizes power savings during sleep. More...
void	sleep_cycle (int interval=5)
	Sleep function for periodic sleeping. More...
int	schedule (struct pt *pt=&sched_thd)
	Controls general measurement schedule. More...

Variables
static struct pt	sched_thd
	Protothread control structure for measure()
static RTC_DS3231	rtc_ds
	Instance of our real-time clock.
static bool	sleep
	Global flag to prep for sleep.

Function Documentation

alarmISR()

void alarmISR

(

void

)

Interrupt handler for RTC alarm.

Called when the feather wakes up from sleep. Disables the RTC interrupt.

Definition at line 5 of file schedule.cpp.

                {
  // Reset the alarm.
  rtc_ds.armAlarm(1, false);
 
  // Disable this interrupt
  detachInterrupt(digitalPinToInterrupt(ALARM_PIN));
}

feather_sleep()

void feather_sleep

(

void

)

Maximizes power savings during sleep.

Steps for going to sleep:

1. Attach interrupt to RTC pin
2. Disconnect from the SD card
3. Disconnect from Serial and USB
4. Turn off power rails and status LED
5. Begin deep sleep

Steps for waking up:

1. Attach USB and Serial
2. Turn on power rails and status LED
3. Open SD card

Definition at line 13 of file schedule.cpp.

                          {MARK();
  // Wait for the alarm to clear
  while(!digitalRead(ALARM_PIN)){
    pinMode(ALARM_PIN, INPUT_PULLUP);
    Serial.print("Waiting on alarm pin...");
    delay(10);
  }MARK();
  // Disable SPI to save power
  pinMode(SPI_SCK, INPUT);
  pinMode(SPI_MOSI, INPUT);
  pinMode(SD_CS, INPUT);
  // Turn off power rails
  digitalWrite(EN_3v3, HIGH); 
  digitalWrite(EN_5v, LOW);
  digitalWrite(STATUS_LED, LOW);MARK();
  Serial.println("Sleeping");
  halt_location.pause();
#if 1
  // Prep for sleep
  Serial.end();
  USBDevice.detach();
  // Low-level so we can wake from sleep
  // We have to call this twice - maybe a synchronization issue?
  attachInterrupt(digitalPinToInterrupt(ALARM_PIN), alarmISR, LOW);
  attachInterrupt(digitalPinToInterrupt(ALARM_PIN), alarmISR, LOW);
  // Sleep
  LowPower.standby();
 
  // Prep to resume
  USBDevice.attach();
  Serial.begin(115200);
#else
  // Pretend to sleep, so the serial terminal doesn't exit
  // This draws a lot of power, so don't do this in production
  while(digitalRead(ALARM_PIN));
#endif
  // Resume the watchdog
  halt_location.read();
  halt_location.print();
  halt_location.resume();
  MARK();
  // Enable the power rails
  digitalWrite(STATUS_LED, HIGH);
  digitalWrite(EN_3v3, LOW); 
  digitalWrite(EN_5v, HIGH);
  // Start the SD card again
  pinMode(SPI_SCK, OUTPUT);
  pinMode(SPI_MOSI, OUTPUT);
  pinMode(SD_CS, OUTPUT);MARK();
  sd.begin(SD_CS, SD_SCK_MHZ(1));MARK();
}

schedule()

int schedule

(

struct pt *

pt = &sched_thd

)

Controls general measurement schedule.

This is the schedule:

1. Measure temperature of tree (before heat is applied)
2. Apply heat pulse
3. Wait for the peak of the heat to reach the upper and lower probes.
4. Measure the sap flow
5. Sleep until next measurement cycle

   Parameters

   pt	A pointer to the protothread control structure. The default parameter is correct. Don't forget to initialize the control structure in setup().

   Returns

   the status of the protothread (Waiting, yeilded, exited, or ended)

Definition at line 81 of file schedule.cpp.

{
  PT_BEGIN(pt);
  Serial.print("Initializing schedule thread... ");
  // RTC Timer settings here
  if (! rtc_ds.begin()) {
    Serial.println("Couldn't find RTC");
  }
  // If this is a new RTC, set the time
  if (rtc_ds.lostPower()) {
    Serial.println("RTC lost power, lets set the time!");
    // Set the RTC to the date & time this sketch was compiled
    rtc_ds.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
  Serial.println("Done");
  // This is the main schedule for the program
  while (1)
  {
    Serial.print("Awoke at ");MARK();
    Serial.println(rtc_ds.now().text());MARK();
    PT_WAIT_THREAD(pt, baseline());MARK(); //<Measure the baseline temp
    digitalWrite(HEATER, HIGH);MARK(); //< Turn on the heater
    Serial.print("Heater On at ");MARK();
    Serial.println(rtc_ds.now().text());MARK();
    PT_TIMER_DELAY(pt,6000);MARK(); //< Heater is on for 6 seconds
    digitalWrite(HEATER, LOW);MARK(); //< Turn off the heater
    Serial.print("Heater Off at ");MARK();
    Serial.println(rtc_ds.now().text());MARK();
    PT_TIMER_DELAY(pt,100);MARK();  //< Wait for heat to propagate
    Serial.println("Temperature probably reached plateau");MARK();
    PT_WAIT_THREAD(pt, delta());MARK(); //<Calculate the sapflow
    Serial.println("Finished logging");MARK();
    sleep_cycle(5); MARK(); //<Sleep until the next multiple of 5 minutes
    sleep = false;
  }
  PT_END(pt);
}

sleep_cycle()

void sleep_cycle

(

int

interval = 5

)

Sleep function for periodic sleeping.

Sleep until the time is a round multiple of the minute inteval. Produces unexpected bevahior for non-factors of 60 (7, 8, 9, 11, etc). For example, if it's 5:39 and you select an interval of 15, the microcontroller will wake up at 5:45, since 3*15 = 45. This function internally calls feather_sleep() to handle prep and resume from sleeping

Parameters

interval

The increment to sleep for.

Definition at line 67 of file schedule.cpp.

                                {MARK();
  Serial.print("Sleeping until nearest multiple of ");
  Serial.print(interval);
  Serial.println(" minutes");MARK();
  DateTime t = rtc_ds.now();MARK();
  t = t + TimeSpan( interval * 60 );MARK();
  uint8_t minutes = interval*(t.minute()/interval);MARK();
  rtc_ds.setAlarm(ALM2_MATCH_MINUTES, minutes, 0, 0);MARK();
  Serial.print("Alarm set to ");MARK();
  t = rtc_ds.getAlarm(2);MARK();
  Serial.println(t.text());MARK();
  feather_sleep();MARK();
}