Feature: Scheduled Relay Control

Complexity: 🟡 Medium Hardware Required: 🔧 Minor (RTC module) User Value: ⭐⭐⭐ Essential

Overview

Enable time-based scheduling for relay activation and deactivation, allowing relays to turn on/off at specific times of day, days of week, or date ranges. Perfect for lighting control, HVAC systems, or any automation that follows a schedule.

Benefits

• Automatic lighting control
• Energy savings through scheduled operation
• Business hours automation
• Seasonal adjustments
• No manual intervention needed
• Override capability for holidays

Schedule Types

1. Daily Schedules - Same time every day
2. Weekly Schedules - Different times for different days
3. Date Range - Active only during specific dates
4. Recurring Events - Monthly, yearly patterns
5. Exception Days - Holidays, special events

Implementation Checklist

Phase 1: Schedule Data Structure

• Define schedule system:

  struct RelaySchedule {
      bool enabled;
      uint8_t relayNumber;
  
      // Time windows (up to 4 per relay)
      struct TimeWindow {
          uint8_t startHour;
          uint8_t startMinute;
          uint8_t endHour;
          uint8_t endMinute;
          uint8_t daysOfWeek;  // Bitmask: Sun=1, Mon=2, etc.
          bool active;
      } windows[4];
  
      // Date restrictions
      uint32_t validFrom;    // Unix timestamp (0 = no restriction)
      uint32_t validUntil;   // Unix timestamp (0 = no restriction)
  
      // Override settings
      bool overrideActive;
      bool overrideState;    // ON/OFF during override
  };
  

Phase 2: Schedule Controller

• Create ScheduleController class:

  class ScheduleController {
  private:
      RelaySchedule schedules[NUM_RELAYS];
      DateTime lastCheck;
      RelayController* relayCtrl;
      TimeController* timeCtrl;
  
  public:
      bool begin(RelayController* rc, TimeController* tc);
      void checkSchedules();  // Call frequently in loop()
  
      // Schedule management
      void setSchedule(uint8_t relay, const RelaySchedule& schedule);
      RelaySchedule getSchedule(uint8_t relay);
      void enableSchedule(uint8_t relay, bool enable);
  
      // Time window management
      void addTimeWindow(uint8_t relay, uint8_t window,
                        uint8_t startH, uint8_t startM,
                        uint8_t endH, uint8_t endM,
                        uint8_t days);
      void removeTimeWindow(uint8_t relay, uint8_t window);
  
      // Override functions
      void setOverride(uint8_t relay, bool state, uint32_t duration);
      void clearOverride(uint8_t relay);
      void clearAllOverrides();
  
      // Persistence
      void saveSchedules();
      void loadSchedules();
  };
  

Phase 3: Common Use Cases

• Preset schedules:

  // Business Hours Lighting
  RelaySchedule businessLighting = {
      .enabled = true,
      .relayNumber = 2,
      .windows = {
          {8, 0, 18, 0, 0b01111100, true},  // M-F 8AM-6PM
          {10, 0, 14, 0, 0b01000000, true}, // Sat 10AM-2PM
      }
  };
  
  // Security Lighting (Dusk to Dawn)
  RelaySchedule securityLighting = {
      .enabled = true,
      .relayNumber = 3,
      .windows = {
          {18, 30, 23, 59, 0b11111111, true}, // 6:30PM-Midnight
          {0, 0, 6, 30, 0b11111111, true},    // Midnight-6:30AM
      }
  };
  
  // HVAC Schedule
  RelaySchedule hvacSchedule = {
      .enabled = true,
      .relayNumber = 4,
      .windows = {
          {7, 0, 9, 0, 0b01111100, true},   // M-F Morning
          {17, 0, 22, 0, 0b01111100, true}, // M-F Evening
          {8, 0, 22, 0, 0b11000011, true},  // Weekends all day
      }
  };
  

Phase 4: Advanced Scheduling

• Sunrise/Sunset Calculation:

  struct LocationConfig {
      float latitude;
      float longitude;
      int8_t timezone;
  };
  
  void calculateSunriseSunset(DateTime date,
                              float& sunrise,
                              float& sunset);
  
  // Automatic adjustment for outdoor lighting
  void adjustForDaylight(RelaySchedule& schedule);
  

• Holiday Management:

  struct Holiday {
      uint8_t month;
      uint8_t day;
      char name[16];
      bool skipSchedule;  // Skip normal schedule
      RelaySchedule override;  // Special schedule
  };
  
  Holiday holidays[20];  // Store up to 20 holidays
  

• Learning Mode:

  // Learn patterns from manual operation
  void recordManualOperation(uint8_t relay, bool state);
  void suggestSchedule(uint8_t relay);
  

Phase 5: User Interface

• Serial commands:

  SCHEDULE SET <relay> <window> <start> <end> <days>
  SCHEDULE ENABLE <relay> <true/false>
  SCHEDULE OVERRIDE <relay> <ON/OFF> <minutes>
  SCHEDULE CLEAR <relay>
  SCHEDULE LIST
  SCHEDULE HOLIDAY <date> <name> <relay> <action>
  TIME SET <YYYY-MM-DD HH:MM:SS>
  

• Example commands:

  SCHEDULE SET 2 1 08:00 18:00 MTWTF    // Relay 2 on M-F 8AM-6PM
  SCHEDULE SET 3 1 SUNSET SUNRISE ALL   // Relay 3 sunset to sunrise
  SCHEDULE OVERRIDE 1 ON 60             // Override relay 1 ON for 60 min
  SCHEDULE HOLIDAY 2024-12-25 Christmas 2 OFF  // Relay 2 off on Christmas
  

Phase 6: Integration Features

• Cascade Control:

  // One relay schedule triggers another
  struct CascadeRule {
      uint8_t sourceRelay;
      uint8_t targetRelay;
      int8_t delayMinutes;  // + for after, - for before
      bool invertState;     // Target opposite of source
  };
  

• Conditional Scheduling:

  // Schedule based on sensor input
  struct ConditionalSchedule {
      uint8_t sensorPin;
      int16_t threshold;
      bool aboveThreshold;  // Activate when above/below
      RelaySchedule schedule;
  };
  

Phase 7: Visual Feedback

• LED indicators for schedule status:
  • Solid: Schedule active, relay on
  • Slow blink: Schedule active, relay off
  • Fast blink: Override active
  • Off: Schedule disabled
• Audio notifications:
  • Chime when schedule activates
  • Different tones for on/off
  • Alert for override activation

Memory Management

EEPROM Layout

Address    Content
200-299    Relay 1 Schedules
300-399    Relay 2 Schedules
400-499    Relay 3 Schedules
500-599    Relay 4 Schedules
600-649    Holidays
650-699    Location config
700+       Reserved

SD Card Storage (if available)

/SCHEDULES/
├── relay1.json
├── relay2.json
├── relay3.json
├── relay4.json
├── holidays.json
└── history.log

Testing Checklist

• Basic schedule on/off
• Multi-window schedules
• Day of week restrictions
• Date range validation
• Override functionality
• Holiday handling
• RTC accuracy
• Power loss recovery
• Daylight saving time

Example Applications

1. Parking Lot Lights: On at sunset, off at sunrise
2. Office HVAC: On at 7 AM, off at 6 PM weekdays
3. Store Sign: On during business hours + 1 hour
4. Greenhouse: Multiple windows for different seasons
5. Pool Pump: Run 4 hours in morning, 4 in evening

Future Enhancements

• Web interface for schedule management
• Mobile app with calendar view
• Integration with weather data
• Astronomical calculations (moon phases)
• Energy usage tracking and optimization
• Machine learning for optimal scheduling