rainmaker - Trigger (rain) output for warm and dry ambient state

Arduino UNO based controller using BME280 environmental sensor to output a relay signal for warm and dry ambient state.

Features

• Initialization
  • [X] Read configuration parameters from EEPROM
  • [X] Print configuration parameters to serial
  • [X] LCD output rainmaker + version number
• Hardware
  • [X] Temperature and humidity sensor AM2320
  • [X] 2x16 LCD display shield
    • [X] select button NEXT
    • [X] left button SELECT
• Normal operation
  • [X] Read and show temperature and humidity
  • [X] Rain operation active
  • [X] Blank display after idle timeout
• Configuration operation
  • [X] Rain operation inactive
  • Configuration values
    • [X] Configure temperature threshold (TH)
    • [X] Configure humidity threshold (RH)
    • [X] Configure blank LCK idel timeout (IDLE)
    • [X] Configure rain delay (DEL)
    • [X] Configure rain duration (DUR)
    • [X] Change rain delay timer for debug purposes (TMR)
  • Configuration functions
    • [X] Menu choice to show configuration value
    • [X] Menu choice to choose configuration value
    • [X] Menu choice to change configuration value
    • [X] Menu choice to persist changes in EEPROM
• Rain operation
  • [X] Rain if temp exceed limit and RH less than limit
  • [X] Time interval between rainy periods (DLY)
  • [X] Rain lasts for a duration (DUR)
  • [X] Output signal (RAIN) when should rain
• Keyboard
  • [X] Debounce timeout
  • [X] Two key operation (select and set)

Functional Description

State Model

State Model Behavior

At a high level, rainmaker is a state machine Main with two states MainStarting and MainOperating.

MainStarting transitions to MainOperating after reading parameters from EEPROM, and configuring controller pins and peripherals.

MainOperating runs three state machines in parallel:

1. SelectButton to check pressing of select button,
2. SetButton to check pressing of set button, and
3. Display to read inputs from sensor and buttons, and to control output to LCD and to output pins.

State machine Display implements modes ConfiguringMode and OperatingMode.

OperatingMode -mode includes states DisplayMain and DisplayIdle. Both of these states read environment sensor and execute state machine Rain. DisplayMain reads and updates ambient state to LCD display using state machine UpdateMeasurement. The corresponding state machine, IdleMeasurement, in DisplayMain reads ambient state and blanks LCD. DisplayMain runs state machine IdleChecker to trigger timeout transition from DisplayMain to DisplayIdle. Pressing either select or set -button, when in DisplayIdle, resumes control back to DisplayMain state.

States of state machine Rain use ambient state and two timers:

1. state NoRain: Entered, when ambient temperature is below parameter TH limit OR relative humidity greater than parameter RH limit.
2. state WaitToRain : Entered, when temperature above parameter TH limit and relative humidity less than parameter RH limit and RAIN_DELAY timer has not elapsed. Output signal RAIN is off.
3. state Raining: Entered, when temperature above parameter TH limit and relative humidity less than parameter RH limit and RAIN_DELAY timer has elapsed and RAIN_DURATION has not elapsed. Output signal RAIN is on.

Configuration -mode is invoked by pressing select button in DisplayMain -state. In Configuring state button select chooses next parameter to configure. set button transitions to state ConcigureSet, which allows choosing parameter value with select button and resuming back to Configuring state with set button. After all configuration parameters have been processed, pressing select transitions to ConfigurePersist, where set button persists parameter values to EEPROM and resumes back to DisplayMain. Button select resumes back to DisplayMain without making changes permanent.

Config

ConfigSlot slots[CONFIG_SLOTS] = {
  {
    "TH"                // warm temperature threshold
    ,&temp_too_treshold
    ,5                  // increment by 5 degrees
    ,50                 // max 50 deg
    ,20                 // min 20 deg
    ,1                  // save to eeprom 0 address
  },
  {
    "RH"                // dry/humid threshold
    ,&relative_humidity_treshold
    ,5                  // increment
    ,100                // max
    ,30                 // min
    ,2                  // save to EEPROM address slot
  },
  {
    "IDLE"              // Timeout before blanking LCD
    ,&idle_timeout      // idle timeout (seconds)
    ,30                 // increment
    ,600                // max 10 min
    ,30                 // min
    ,3                  // save to EEPROM address slot
  },
  {
    "DLY"               // Rain delay, number of ticks between showers
    ,&rain_delay        // delay * 15 mins between rain showever
    ,1                  // increment by slot count
    ,RAIN_DELAY_MAX     // max 8*15 mins = 2 hours
    ,1                  // min 1 slot = 15 mins
    ,4                  // save to EEPROM address slot
  },
  {
    "DUR"               // Rain duration = length of shower
    ,&rain_duration     // delay * 15 mins between rain showever
    ,10                 // increment 10 sec slots
    ,120                // max 120 secs = 2 minutes
    ,10                 // min 10 secs
    ,5                  // save to EEPROM address slot
  },
  {
    "TMR"               // Current counter value, allow change but NOT persist
    ,&rainTimer         // delay * 15 mins between rain showever
    ,RAIN_DELAY_TICK    // increment counter by tick size
    ,RAIN_DELAY_TICK * RAIN_DELAY_MAX 
                        // max to rain delay = number of ticks between showers
    ,0                  // min = start counter from 0
    ,0                  // NOT saved to EEPROM
  }  
};

Hardware Configs

// Hardware settings:
// Lcd-shield pins
const int lcd_pin1=8;
const int lcd_pin2=9;
const int lcd_pin3=4;
const int lcd_pin4=5;
const int lcd_pin5=6;
const int lcd_pin6=7;

// Analog inputs
const int lcd_button_port=0;
const int lcd_backligh_port=10;

// Hardware settings.