// 4. Check if it's time to regenerate (if scheduled and within time window) if (regeneration_pending && current_hour == regeneration_time_hour) execute_regeneration_cycle(); regeneration_pending = false; total_flow_m3 = 0.0; // reset consumption meter

// Step 6: Return to service move_valve_to(SERVICE);

// 3. Decide if regeneration needed if ( (capacity_total - consumed) < (capacity_total * 0.15) ) // less than 15% capacity left schedule_regeneration();

// Step 5: Refill brine tank move_valve_to(BRINE_REFILL); delay_minutes(12); // depending on salt amount needed

void loop() // 1. Read current hardness (could be from an inline sensor or manual input) hardness_raw = read_user_hardness_setting(); // 2. Calculate consumed capacity float consumed = total_flow_m3 * 1000 * hardness_raw; // in grams equivalent

def calculate_remaining_capacity(): # Remaining softening capacity (liters) # capacity_total = resin volume (L) * exchange capacity (eq/L) / hardness (eq/L) available_capacity_liters = capacity_total / hardness_raw

enum ValvePosition SERVICE, BACKWASH, BRINE_DRAW, SLOW_RINSE, FAST_RINSE, BRINE_REFILL ; void execute_regeneration_cycle() // Step 1: Backwash (reverse flow to clean resin) move_valve_to(BACKWASH); delay_minutes(10);

// Step 4: Fast rinse (final cleaning) move_valve_to(FAST_RINSE); delay_minutes(8);