Finite-State

Finite-State Machine for Arduino

typedefstruct {Predicatepredicate;// Predicate Function Pointerid_tnextF;// Next State on FALSEid_tnextT;// Next State on TRUEProcessprocess;// Process Function PointerEventHandlereventHandler;// Event Function Pointertime_tdelayTime;// Delay TimeTimerTypetimerType;// Timer Type}Transition;

Predicate Function

typedefbool (*Predicate)(id_t);//  Predicate Function Pointer

boolPredicateCallbackFunction(id_tid);//  Predicate Callback Function

boolPredicateCallbackFunction(id_tid) {// TODO: PREDICATE FUNCTIONreturnbutton[id].isPressed(); }

boolPredicateCallbackFunction(id_tid) {// TODO: PREDICATE FUNCTIONreturnarray[id]==10; }

Next State

Process Function

typedefvoid (*Process)(id-t);//  Process Function Pointer

voidProcessCallbackFunction(id_tid);//  Process Callback Function

voidMotorProcess(id_tid) {StatusStatestatus;if (motor[id].timerON) {if (motor[id].running) {status=RUNNING;    }else {status=FAULT;    }digitalWrite(motor[id].faultPin,status==FAULT);  }}

id_tid=finiteStateMachine.id;

Event Handler Function

typedefvoid (*EventHandler)(EventArgs);//  Event Handler Function Pointer

typedefstruct {id_tid;// State idActionaction;// Action State}EventArgs;

enumAction {DURING,EXIT,ENTRY};

voidEventCallbackFunction(EventArgse);//  Event Callback Function

voidEvnetOnActionChanged(EventArgse) {switch (e.action) {caseENTRY:digitalWrite(motor[e.id].output, true);break;caseDURING:// TODO: SOMETHINGbreak;caseEXIT:digitalWrite(motor[e.id].output, false);break;  }}

Timer

enumTimerType {NOT_USED,// Not Used TimerTRANS_TIMER,// Transition TimerPREDIC_TIMER,// Predicate TimerFALSE_TIMER,// False State TimerTRUE_TIMER,// True State Timer};

Not Used Timer (NOT_USED)

Not-Used Timer Next-State Flow

Typical Not-Used Timer State Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {PredicateCallbackFunction,0,1,ProcessCallbackFunction,EventCallbackFunction},// State-0 - NextF = 0, NextT = 1  {PredicateCallbackFunction,1,0,ProcessCallbackFunction,EventCallbackFunction}// State-1 - NextF = 1, NextT = 0};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);// Number of TransitionsFiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State Object

Transition Timer (TRANS_TIMER)

Transition-Timer Next-State Flow

Typical Transition-Timer State Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {nullptr,0,1,ProcessCallbackFunction,EventCallbackFunction,3000,TRANS_TIMER},// State-0 - NextF = 0, NextT = 1  {nullptr,1,0,ProcessCallbackFunction,EventCallbackFunction,5000,TRANS_TIMER}// State-1 - NextF = 1, NextT = 0};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);// Number of TransitionsFiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State Object

Predicate Timer (PREDIC_TIMER)

Predicate-Timer Next-State Flow

Typical Predicate-Timer State Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {PredicateCallbackFunction,0,1,ProcessCallbackFunction,EventCallbackFunction,3000,PREDIC_TIMER},// State-0 - NextF = 0, NextT = 1  {PredicateCallbackFunction,1,0,ProcessCallbackFunction,EventCallbackFunction,5000,PREDIC_TIMER}// State-1 - NextF = 1, NextT = 0};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);// Number of TransitionsFiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State Object

False-State Timer (FALSE_TIMER)

False-Timer Next-State Flow

Typical False-Timer State Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {PredicateCallbackFunction,1,0,ProcessCallbackFunction,EventCallbackFunction,3000,FALSE_TIMER},// State-0 - NextF = 1, NextT = 0  {PredicateCallbackFunction,0,1,ProcessCallbackFunction,EventCallbackFunction,5000,FALSE_TIMER}// State-1 - NextF = 0, NextT = 1};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);// Number of TransitionsFiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State Object

True-State Timer (TRUE_TIMER)

True-Timer Next-State Flow

Typical True-Timer State Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {PredicateCallbackFunction,0,1,ProcessCallbackFunction,EventCallbackFunction,3000,TRUE_TIMER},// State-0 - NextF = 0, NextT = 1  {PredicateCallbackFunction,1,0,ProcessCallbackFunction,EventCallbackFunction,5000,TRUE_TIMER}// State-1 - NextF = 1, NextT = 0};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);// Number of TransitionsFiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State Object

Example

Fan Control With A Thermostat

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {FanStartPredicate,0,1,StartFanProcess},// State-0 - NextF = 0, NextT = 1  {FanStopPredicate,1,0,StopFanProcess}// State-1 - NextF = 1, NextT = 0};

Sketch

#include"FiniteState.h"#definethermostatPin   A0#definestartStatusPin  5#definestopStatusPin   6uint8_tstatusPins[]= {stopStatusPin,startStatusPin};constuint8_tnumberOfStatus=sizeof(statusPins) /sizeof(uint8_t);voidStartFanProcess(id_tid);voidStopFanProcess(id_tid);boolFanStartPredicate(id_tstate);boolFanStopPredicate(id_tstate);Transitiontransitions[]= {  {FanStartPredicate,0,1,StartFanProcess},// State-0 - NextF = 0, NextT = 1  {FanStopPredicate,1,0,StopFanProcess}// State-1 - NextF = 1, NextT = 0};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);FiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State ObjectconstlongThermostatRead();voidFanControl(id_tid);longtemperature;voidsetup() {for (uint8_tindex=0;index<numberOfStatus;index++) {pinMode(statusPins[index],OUTPUT);digitalWrite(statusPins[index],LOW);  }finiteStateMachine.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {finiteStateMachine.execute();// Execute the FSMtemperature=ThermostatRead();// Read temperature}boolFanStartPredicate(id_tstate) {returntemperature >=40;// Determine Fan Start Action}voidStartFanProcess(id_tid) {FanControl(id);// Fan control output}boolFanStopPredicate(id_tstate) {returntemperature <=30;// Determine Fan Stop Action}voidStopFanProcess(id_tid) {FanControl(id);// Fan control output}voidFanControl(id_tid) {for (uint8_tindex=0;index<numberOfStatus;index++) {boolvalue=index==id;digitalWrite(statusPins[index],value);// Update Status  }}constlongThermostatRead() {longvalue=analogRead(thermostatPin);// Read Pushbutton Valuereturnmap(value,0,1023,0,100);// Scaling temperature}

Traffic Light

Traffic Light with Customized Timer (NOT_USED)

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {DelayTimePredicate,0,1,nullptr,EventOnActionChanged},// State-1 - NextF = 0, NextT = 1  {DelayTimePredicate,1,2,nullptr,EventOnActionChanged},// State-2 - NextF = 1, NextT = 2  {DelayTimePredicate,2,0,nullptr,EventOnActionChanged},// State-3 - NextF = 2, NextT = 0};

Sketch

#include"FiniteState.h"#defineredLightPin     5#defineyellowLightPin  4#definegreenLightPin   3uint8_tlightPins[]= {redLightPin,greenLightPin,yellowLightPin};// Define an array of light pins.constuint8_tnumberOfLights=sizeof(lightPins) /sizeof(uint8_t);// Calculate the number of lights.typedefstruct {unsigned longdelayTime;unsigned longstartTime;}Timer;TimerdelayTimes[]= {  {5000},// RED Delay Time 5 seconds  {10000},// GREEN Delay Time 10 seconds  {3000},// YELLOW Delay Time 3 seconds};boolDelayTimePredicate(id_tid);// Predicate (Input)voidEventOnActionChanged(EventArgse);// Event StateTransitiontransitions[]= {  {DelayTimePredicate,0,1,nullptr,EventOnActionChanged},// State-1 - NextF = 0, NextT = 1  {DelayTimePredicate,1,2,nullptr,EventOnActionChanged},// State-2 - NextF = 1, NextT = 2  {DelayTimePredicate,2,0,nullptr,EventOnActionChanged},// State-3 - NextF = 2, NextT = 0};constuint8_tnumberOftransitions=sizeof(transitions) /sizeof(Transition);// Calculate the number of transitions.FiniteStatefiniteStateMachine(transitions,numberOftransitions);// Define Finite-State Objectvoidsetup() {for (uint8_tindex=0;index<numberOfLights;index++) {pinMode(lightPins[index],OUTPUT);// Set Pin ModedigitalWrite(lightPins[index],LOW);// Set Light with the LOW state.  }finiteStateMachine.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {finiteStateMachine.execute();// Execute the FSM}boolDelayTimePredicate(id_tid) {return (millis()-delayTimes[id].startTime >=delayTimes[id].delayTime);// Determine Time Delay}voidEventOnActionChanged(EventArgse) {switch (e.action) {caseENTRY:delayTimes[e.id].startTime=millis();// Reload start timedigitalWrite(lightPins[e.id],HIGH);// Set Light with the HIGH state.break;caseEXIT:digitalWrite(lightPins[e.id],LOW);// Set Light with the LOW state.break;  }}

Traffic Light with Transition Timer (TRANS_TIMER)

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {nullptr,0,1,nullptr,EventOnActionChanged,5000,TRANS_TIMER},// State-1 - NextF = 0, NextT = 1  {nullptr,1,2,nullptr,EventOnActionChanged,10000,TRANS_TIMER},// State-2 - NextF = 1, NextT = 2  {nullptr,2,0,nullptr,EventOnActionChanged,3000,TRANS_TIMER},// State-3 - NextF = 2, NextT = 0};

Sketch

#include"FiniteState.h"#defineredLightPin     5#defineyellowLightPin  4#definegreenLightPin   3uint8_tlightPins[]= {redLightPin,greenLightPin,yellowLightPin};// Define an array of light pins.constuint8_tnumberOfLights=sizeof(lightPins) /sizeof(uint8_t);// Calculate the number of lights.voidEventOnActionChanged(EventArgse);// Event StateTransitiontransitions[]= {  {nullptr,0,1,nullptr,EventOnActionChanged,5000,TRANS_TIMER},// State-1 - NextF = 0, NextT = 1  {nullptr,1,2,nullptr,EventOnActionChanged,10000,TRANS_TIMER},// State-2 - NextF = 1, NextT = 2  {nullptr,2,0,nullptr,EventOnActionChanged,3000,TRANS_TIMER},// State-3 - NextF = 2, NextT = 0};constuint8_tnumberOftransitions=sizeof(transitions) /sizeof(Transition);// Calculate the number of transitions.FiniteStatefiniteStateMachine(transitions,numberOftransitions);// Define Finite-State Objectvoidsetup() {for (uint8_tindex=0;index<numberOfLights;index++) {pinMode(lightPins[index],OUTPUT);// Set Pin ModedigitalWrite(lightPins[index],LOW);// Set Light with the LOW state.  }finiteStateMachine.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {finiteStateMachine.execute();// Execute the FSM}voidEventOnActionChanged(EventArgse) {switch (e.action) {caseENTRY:digitalWrite(lightPins[e.id],HIGH);// Set Light with the HIGH state.break;caseEXIT:digitalWrite(lightPins[e.id],LOW);// Set Light with the LOW state.break;  }}

Coin Operated Turnstile

Coin Operated Turnstile with Predicate and Process

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {CoinPredicate,0,1,LockedProcess},// State-0 - NextF = 0, NextT = 1  {PushPredicate,1,0,UnlockedProcess}// State-1 - NextF = 1, NextT = 0};

Sketch

#include"FiniteState.h"#include"RepeatButton.h"#defineCOIN      A0  // Define the Coin input pin.#definePUSH      A1  // Define the Push input pin.#defineLOCKED    7   // Define the Locked state output pin.#defineUNLOCKED  6   // Define the Unlocked state output pin.boolCoinPredicate(id_tid);// Declare Coin Predicate functionboolPushPredicate(id_tid);// Declare Push Predicate functionvoidLockedProcess(id_tid);// Declare Locked Process functionvoidUnlockedProcess(id_tid);// Declare Unlocked Process functionTransitiontransitions[]= {  {CoinPredicate,0,1,LockedProcess},// State-0 - NextF = 0, NextT = 1  {PushPredicate,1,0,UnlockedProcess}// State-1 - NextF = 1, NextT = 0};constuint8_tNumberOfTransitions=2;// Number Of TransitionsFiniteStatecoinOperatedTurnstile(transitions,NumberOfTransitions);// Finite-State ObjectRepeatButtoncoin;// Declare the Coin RepeatButton objectRepeatButtonpush;// Declare the Push RepeatButton objectvoidsetup() {coin.buttonMode(COIN,INPUT_PULLUP);// Set the Coin input pin modepush.buttonMode(PUSH,INPUT_PULLUP);// Set the Push input pin modepinMode(LOCKED,OUTPUT);// Set the Locked state pin modepinMode(UNLOCKED,OUTPUT);// Set the Unlocked state pin modecoinOperatedTurnstile.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {coin.repeatButton();// Executing the Coin repeat button functionpush.repeatButton();// Executing the Push repeat button functioncoinOperatedTurnstile.execute();// Execute the FSM}boolCoinPredicate(id_tid) {returncoin.isPressed();// Predicate putting a coin.}boolPushPredicate(id_tid) {returnpush.isPressed();// Predicate pushing the arm.}voidLockedProcess(id_tid) {digitalWrite(LOCKED,HIGH);// Turn on the locked position status.digitalWrite(UNLOCKED,LOW);// Turn off the unlocked position status.}voidUnlockedProcess(id_tid) {digitalWrite(LOCKED,LOW);// Turn off the locked position status.digitalWrite(UNLOCKED,HIGH);// Turn on the unlocked position status.}

Coin Operated Turnstile with Predicate and Event

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {inputPredicate,0,1,nullptr,EventOnActionChanged},// State-0 - NextF = 0, NextT = 1  {inputPredicate,1,0,nullptr,EventOnActionChanged}// State-1 - NextF = 1, NextT = 0};

Sketch

#include"FiniteState.h"#include"RepeatButton.h"#defineCOIN      A0  // Define the Coin input pin.#definePUSH      A1  // Define the Push input pin.#defineLOCKED    7   // Define the Locked state output pin.#defineUNLOCKED  6   // Define the Unlocked state output pin.boolinputPredicate(id_tid);// Declare Coin Predicate functionvoidEventOnActionChanged(EventArgse);// Event On Action ChangedTransitiontransitions[]= {  {inputPredicate,0,1,nullptr,EventOnActionChanged},// State-0 - NextF = 0, NextT = 1  {inputPredicate,1,0,nullptr,EventOnActionChanged}// State-1 - NextF = 1, NextT = 0};constuint8_tNumberOfTransitions=2;// Number Of Transitionsuint8_tinputPins[NumberOfTransitions]= {COIN,PUSH};// Declare the Coin RepeatButton objectuint8_toutputPins[NumberOfTransitions]= {LOCKED,UNLOCKED};// Declare the Coin RepeatButton objectFiniteStatecoinOperatedTurnstile(transitions,NumberOfTransitions);// Finite-State ObjectRepeatButtonturnstileInputs[NumberOfTransitions];// Declare the Turnstile Inputs RepeatButton objectvoidsetup() {for (uint8_tindex=0;index<NumberOfTransitions;index++) {turnstileInputs[index].buttonMode(inputPins[index],INPUT_PULLUP);// Set the Turnstile repeat button pin modepinMode(outputPins[index],OUTPUT);// Set the Output state pin mode  }coinOperatedTurnstile.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {for (uint8_tindex=0;index<NumberOfTransitions;index++) {turnstileInputs[index].repeatButton();// Executing the Turnstile repeat button function  }coinOperatedTurnstile.execute();// Execute the FSM}boolinputPredicate(id_tid) {returnturnstileInputs[id].isPressed();// Predicate putting a coin.}voidEventOnActionChanged(EventArgse) {switch (e.action) {caseENTRY:digitalWrite(outputPins[e.id],HIGH);// Turn on the turnstile position status.break;caseEXIT:digitalWrite(outputPins[e.id],LOW);// Turn off the previous turnstile position status.break;  }}

Blink

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {nullptr,0,1,TurnON,nullptr,500,TRANS_TIMER},// State-0 - NextF = 0, NextT = 1  {nullptr,1,0,TurnOFF,nullptr,1000,TRANS_TIMER}// State-1 - NextF = 1, NextT = 0};

Sketch

#include"FiniteState.h"voidTurnON(id_tid);// Declare Turn LED On Process functionvoidTurnOFF(id_tid);// Declare Turn LED Off Process functionTransitiontransitions[]= {  {nullptr,0,1,TurnON,nullptr,500,TRANS_TIMER},// State-0 - NextF = 0, NextT = 1  {nullptr,1,0,TurnOFF,nullptr,1000,TRANS_TIMER}// State-1 - NextF = 1, NextT = 0};constuint8_tNumberOfTransitions=2;// Number Of TransitionsFiniteStateblinkFS(transitions,NumberOfTransitions);// Finite-State Objectvoidsetup() {pinMode(LED_BUILTIN,OUTPUT);// Set the LED_BUILTIN pin modeblinkFS.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {blinkFS.execute();// Execute the FSM}voidTurnON(id_tid) {digitalWrite(LED_BUILTIN,HIGH);// Turn on the LED.}voidTurnOFF(id_tid) {digitalWrite(LED_BUILTIN,LOW);// Turn off the LED.}

Debounce

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {ReadButton,0,1,Released},// State-0 - NextF = 0, NextT = 1  {ReadButton,0,2,nullptr,nullptr,10,TRUE_TIMER},// State-1 - NextF = 0, NextT = 2  {ReadButton,3,2,Pressed},// State-2 - NextF = 3, NextT = 2  {ReadButton,0,2,nullptr,nullptr,10,FALSE_TIMER}// State-3 - NextF = 0, NextT = 2};

Sketch

#include"FiniteState.h"#defineBUTTON  A0  // Define the button input pin.#defineLED     7   // Define the LED output pin.#definedebounce 10 // Debounce Delay 10 millisecondsboolReadButton(id_tid);// Declare Read Button Predicate functionvoidReleased(id_tid);// Declare Released Process functionvoidPressed(id_tid);// Declare Pressed Process functionTransitiontransitions[]= {  {ReadButton,0,1,Released},// State-0 - NextF = 0, NextT = 1  {ReadButton,0,2,nullptr,nullptr,debounce,TRUE_TIMER},// State-1 - NextF = 0, NextT = 2  {ReadButton,3,2,Pressed},// State-2 - NextF = 3, NextT = 2  {ReadButton,0,2,nullptr,nullptr,debounce,FALSE_TIMER}// State-3 - NextF = 0, NextT = 2};constuint8_tNumberOfTransitions=4;// Number Of TransitionsFiniteStatedebounceFS(transitions,NumberOfTransitions);// Finite-State Objectboolstate;voidsetup() {pinMode(BUTTON,INPUT_PULLUP);// Set the Button pin modepinMode(LED,OUTPUT);// Set the LED pin modedebounceFS.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {debounceFS.execute();// Execute the FSMdigitalWrite(LED,state);// Set LED with the state.}boolReadButton(id_tid) {return !digitalRead(BUTTON);// Read Button value.}voidReleased(id_tid) {state= false;// Set the state with false value.}voidPressed(id_tid) {state= true;// Set the state with true value.}

Analog High-Alarm

State Diagram

Wiring Diagram

State-Transition Table

State-Transition Table -> Transition Declaration

Transitiontransitions[]= {  {AnalogPredicate,0,1,NormalProcess},// State-0 - NextF = 0, NextT = 1  {AnalogPredicate,0,2,PreAlarmProcess,nullptr,alarmDelay,TRUE_TIMER},// State-1 - NextF = 0, NextT = 2  {AnalogPredicate,2,0,HighAlarmProcess}// State-2 - NextF = 2, NextT = 0};

Sketch

#include"FiniteState.h"#defineprocessValuePin A0  // Define the Process value input pin.#definenormalPin       6   // Define the normal status output pin.#definepreAlarmPin     5   // Define the pre-alarm status output pin.#definehighAlarmPin    4   // Define the high-alarm status output pin.enumOperator {LT,// Less than operatorLE,// Less than or equal operatorGT,// Greater than operatorGE// Greater than or equal operator};constlongsetpoint=85;// Alarm Setpointconstlongdeadband=5;// Alarm DeadbandOperatoroperators []= {GE,GE,LT};// Comparison operatorslongsetpoints []= {setpoint,setpoint,setpoint-deadband};// Comparison setpointsconstlongAnalogRead();// Declare Analog Read FunctionvoidProcessAlarmStatus(boolnormal,boolpreAlarm,boolhighAlarm);// Declare Process Alarm Status FunctionlongprocessValue;// Declare processValue variableboolAnalogPredicate(id_tid);// Declare analog predicate FunctionvoidNormalProcess(id_tid);// Declare normal process FunctionvoidPreAlarmProcess(id_tid);// Declare pre-alarm process FunctionvoidHighAlarmProcess(id_tid);// Declare high-alarm process Function#definealarmDelay 3000         // Define alarm dalayTransitiontransitions[]= {  {AnalogPredicate,0,1,NormalProcess},// State-0 - NextF = 0, NextT = 1  {AnalogPredicate,0,2,PreAlarmProcess,nullptr,alarmDelay,TRUE_TIMER},// State-1 - NextF = 0, NextT = 2  {AnalogPredicate,2,0,HighAlarmProcess}// State-2 - NextF = 2, NextT = 0};constuint8_tnumberOfTransitions=sizeof(transitions) /sizeof(Transition);// Number of TransitionsFiniteStatefiniteStateMachine(transitions,numberOfTransitions);// Finite-State Objectvoidsetup() {pinMode(normalPin,OUTPUT);// Set the normal LED pin modepinMode(preAlarmPin,OUTPUT);// Set the pre-alarm LED pin modepinMode(highAlarmPin,OUTPUT);// Set the hith-alarm LED= pin modefiniteStateMachine.begin(0);// FSM begins with Initial Transition Id 0}voidloop() {finiteStateMachine.execute();// Execute the FSMprocessValue=AnalogRead();// Read processValue}voidNormalProcess(id_tid) {ProcessAlarmStatus(true, false, false);// Update process alarm status}voidPreAlarmProcess(id_tid) {ProcessAlarmStatus(false, true, false);// Update process alarm status}voidHighAlarmProcess(id_tid) {ProcessAlarmStatus(false, true, true);// Update process alarm status}boolAnalogPredicate(id_tid) {boolvalue;switch (operators[id]) {caseGE:value=processValue >=setpoints[id];// Compare process value with setpointbreak;caseLT:value=processValue<setpoints[id];// Compare process value with setpointbreak;default:value= false;break;  }returnvalue;}voidProcessAlarmStatus(boolnormal,boolpreAlarm,boolhighAlarm) {digitalWrite(normalPin,normal);// Update normal statusdigitalWrite(preAlarmPin,preAlarm);// Update pre-alarm statusdigitalWrite(highAlarmPin,highAlarm);// Update high-alarm status}constlongAnalogRead() {longvalue=analogRead(processValuePin);// Read Process Valuereturnmap(value,0,1023,0,100);// Scaling processValue}

References