fan controlled by temperature

hi,

i creating project fan start @ temperature. if temperature below min temp want green led light , fan not run, between min temp , max temp want orange led light , fan start , reach 50% fan speed. when max temp reached want red led light , 100% fan speed reached.

when download code fan starts automatically though temp below temp min , red led lights up, not green led supposed alight.

i new arduino , know basics think simple causing happen have tried resolve many times still cant work out.


here code, if can see why not work great help.

thank you

code: [select]


//code scratch

int pos = 0;                           
int sensorpin = a1;                      //temp sensor
int reading = 0;                         //read temp
int fan = 11;                            //fan
int ledgreen = 8;                        //green led
int ledorange = 7;                       //orange led
int ledred = 5;                          //red led
int tempmin = 10;                        //temp fan starts
int tempmax = 35;                        //temp fan reaches max speed
int fanspeed;

float voltage = 0;                        //convert temp
float temperaturec = 0;                   //convert temp
float temperaturef = 0;                   //convert temp

void setup()  {
  pinmode(sensorpin, input);
  pinmode(fan, output);
  pinmode(ledgreen, output);
  pinmode(ledorange, output);
  pinmode(ledred, output);
  serial.begin(9600);
}


void loop()  {

  if(temperaturec<tempmin){                           //if temp below temp min turn off green led
    digitalwrite(fan, low);
    digitalwrite(ledgreen, high);                     
    digitalwrite(ledorange, low);
    digitalwrite(ledred, low);
   
  fanspeed = 0;}
 
  if((temperaturec>=tempmin) &&  (temperaturec<tempmax)){     //if temp same or above temp min , under temp max turn on fan(50% speed), servo , orange led
    digitalwrite(fan, high);
    digitalwrite(ledgreen, low);
    digitalwrite(ledorange, high);
    digitalwrite(ledred, low);

  fanspeed = 50;}
   
   if(temperaturec>tempmax){                    //if temp more temp max turn on fan(100% speed), servo , red led
    digitalwrite(fan,high);
    digitalwrite(ledgreen, low);
    digitalwrite(ledorange, low);
    digitalwrite(ledred, high);
 
  fanspeed = 100;}
   
   
     
}
  int readtemp(){                                             //to convert temperature's
reading = analogread(sensorpin);
voltage = ( reading * 5.0) / 1024.0;
temperaturec = (voltage - 0.5) * 100;
temperaturef = temperaturec * 9/5 + 32;
 

  serial.print(temperaturec);                               //print text of temp , fan speed on serial monitor
delay(1000);
serial.println(fanspeed);
  delay(1000);
  }
 
 


quote from: hjktimmy on apr 07, 2015, 09:21 pm

hi,

i creating project fan start @ temperature. if temperature below min temp want green led light , fan not run, between min temp , max temp want orange led light , fan start , reach 50% fan speed. when max temp reached want red led light , 100% fan speed reached.

when download code fan starts automatically though temp below temp min , red led lights up, not green led supposed alight.

i new arduino , know basics think simple causing happen have tried resolve many times still cant work out.


here code , fritzing image, if can see why not work great help.

thank you

code: [select]


//code scratch

int pos = 0;                            
int sensorpin = a1;                      //temp sensor
int reading = 0;                         //read temp
int fan = 11;                            //fan
int ledgreen = 8;                        //green led
int ledorange = 7;                       //orange led
int ledred = 5;                          //red led
int tempmin = 10;                        //temp fan starts
int tempmax = 35;                        //temp fan reaches max speed
int fanspeed;

float voltage = 0;                        //convert temp
float temperaturec = 0;                   //convert temp
float temperaturef = 0;                   //convert temp

void setup()  {
  pinmode(sensorpin, input);
  pinmode(fan, output);
  pinmode(ledgreen, output);
  pinmode(ledorange, output);
  pinmode(ledred, output);
  serial.begin(9600);
}


void loop()  {

  if(temperaturec<tempmin){                           //if temp below temp min turn off green led
    digitalwrite(fan, low);
    digitalwrite(ledgreen, high);                    
    digitalwrite(ledorange, low);
    digitalwrite(ledred, low);
    
  fanspeed = 0;}
  
  if((temperaturec>=tempmin) &&  (temperaturec<tempmax)){     //if temp same or above temp min , under temp max turn on fan(50% speed), servo , orange led
    digitalwrite(fan, high);
    digitalwrite(ledgreen, low);
    digitalwrite(ledorange, high);
    digitalwrite(ledred, low);

  fanspeed = 50;}
    
   if(temperaturec>tempmax){                    //if temp more temp max turn on fan(100% speed), servo , red led
    digitalwrite(fan,high);
    digitalwrite(ledgreen, low);
    digitalwrite(ledorange, low);
    digitalwrite(ledred, high);
 
  fanspeed = 100;}
  
  
      
}
  int readtemp(){                                             //to convert temperature's
reading = analogread(sensorpin);
voltage = ( reading * 5.0) / 1024.0;
temperaturec = (voltage - 0.5) * 100;
temperaturef = temperaturec * 9/5 + 32;
  

  serial.print(temperaturec);                               //print text of temp , fan speed on serial monitor
delay(1000);
serial.println(fanspeed);
  delay(1000);
  }
  
  


Arduino Forum > Using Arduino > Project Guidance > fan controlled by temperature

arduino