Help with Timer function

Firmware Libraries
1

I want to use Timer to call a function that actuates my servo. However, I do not want to create a new class and complicate the setup with .h and .cpp files. The compiler does not like the use of “this” for the class instance, but since I am working with just setup(), loop(), and member functions, I don’t know how to properly construct the timer objects. I have attached my full program below.

int motor(){
    myservo.write(125);
    return 1;
}
int motorReset(){
    myservo.write(0);
    return 1;
}


int cycleP(String command){
    if(command=="Y"||command=="y"){
        
        Timer t(5, motor(), *this, true);
        Timer t2(30, motorReset(), *this, true);
        t.start();
        t2.start();
      
        myservo.write(0);
        
        return 1;    
    }
    else return -1;
}

full program

#include "Particle.h"
//following 2 lines from Particle support regarding problem with functions publishing
SYSTEM_MODE(SEMI_AUTOMATIC);
SYSTEM_THREAD(ENABLED);

Servo myservo; //unlike arduino, servo is in Particle.h so no need for #include <Servo.h>

int pos = 0;
int led1 = A5; //pin headers are treates as ints - this is why you have to read the OS API documentation! 

int cycleP(String command);
int testFunction(String arg);

unsigned long old_time = 0; //can also use uint32_t from C standard - unsigned 32 bit int
unsigned long old_time2 = 0;
//we need this in order to implement "soft delay" with millis() rather than "hard" delay()

//functions in setup are only run once - via OS API it is recommended to declare "cloud functions" as soon as possible 
//setup is also where you want to declare hardware "attaches" such assigning pins to LEDs, pumps, switches, relays, etc.
void setup(){
    
Particle.function("onOff", cycleP);
Particle.function("inputTest", testFunction);

myservo.attach(D2);
myservo.write(0);

pinMode(led1, OUTPUT);
Particle.connect();
}

void loop(){
    //following 2 if statements make the LED turn on for 1 sec then off for 5 - this allows me to know when updated firmware has flashed and device is online
    if(millis()-old_time>=1000){
        digitalWrite(led1, LOW);
        old_time = millis();
    } 
    if(millis()-old_time2>=5000){
        digitalWrite(led1, HIGH);
        old_time2 = millis();
    }
}

int testFunction(String arg){
    if(arg=="test"){
    return 1;
    }
    else return -1;
}
int motor(){
    myservo.write(125);
    return 1;
}
int motorReset(){
    myservo.write(0);
    return 1;
}


int cycleP(String command){
    if(command=="Y"||command=="y"){
        
        Timer t(5, motor(), *this, true);
        Timer t2(30, motorReset(), *this, true);
        t.start();
        t2.start();
      
        myservo.write(0);
        
        return 1;    
    }
    else return -1;
}
2

I was just trying *this, usually I would use just this

3

@ScruffR Maybe you’ve seen this before. Thanks again with your help on my first post.

4

That very much depends on where you are using it.

this is a pointer to an object itself but whether you need to use this or *this or this->... depends on the context in which you use it.

1 Like
5

Sorry, I meant to tag you on the post not the comment

6

BTW, you are instantiating the timers inside a function so they will vanish once you fall out of that function.

You’d also only use this overload for timer instantiation from within an class member - this is not the case here.

7

Ah yes “function scope”. I will try a different constructor and initialize earlier.

8

You can have global timers and set their period later on inside your function.

9

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