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TM1637 to display temperature. Code question

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Matienzo

Member
Hi there,

I'm trying to display the temperature on a TM1637 display. the variable I'm trying to display is "steinhart". It is declared as a float but when I compile the error reads:"steinhart' was not declared in this scope". Alrighty then, I declare it and displays a 0 on the display. The code is made out of pieces from other codes so it might have discrepancies.

What do you think I'm doing wrong? Thank you for any guidance.

Code:
#include <Servo.h>
#include <TM1637Display.h>

//---------Servo------------

Servo myservo;                // create servo object to control a servo
int potpin = 0;               // analog pin used to connect the potentiometer
int val;        


//-------Thermistor---------

#define TPIN A1                  // which analog pin to connect
#define TRESISTANCE 2500000      // resistance at 25 degrees C
#define TROOM 25                 // temp. for nominal resistance
#define NSAMPLES 5               // how many samples to take and average, more takes longer but is more 'smooth'
#define BCOEFF 3980              // The beta coefficient of the thermistor
#define SERIESRESISTOR 100000    // the value of the 'other' resistor
int samples[NSAMPLES];


//---------Display-------------

const int CLK = 3;                 //Set the CLK pin connection to the display
const int DIO = 2;                 //Set the DIO pin connection to the display
TM1637Display display(CLK, DIO);   //set up the 4-Digit Display.


void setup(void) {

  Serial.begin(9600);
  myservo.attach(8);                // attaches the servo on pin 9 to the servo object
  display.setBrightness(0x0a);      //set the diplay to maximum brightness
 }

void loop(void) {
  {uint8_t i;
  float average;
  for (i=0; i< NSAMPLES; i++) {      // take N samples in a row, with a slight delay
   samples[i] = analogRead(TPIN);
   delay(10);
  }
  average = 0;
   for (i=0; i< NSAMPLES; i++) {
     average += samples[i];
  }
  average /= NSAMPLES;
  average = 1023 / average - 1;
  average = SERIESRESISTOR / average;
  float steinhart;
  steinhart = average / TRESISTANCE;           // (R/Ro)
  steinhart = log(steinhart);                  // ln(R/Ro)
  steinhart /= BCOEFF;                         // 1/B * ln(R/Ro)
  steinhart += 1.0 / (TROOM + 273.15);         // + (1/To)
  steinhart = 1.0 / steinhart;                 // Invert
  steinhart -= 273.15;                         // convert to C
  Serial.print("Temperature ");
  Serial.print(steinhart);
  Serial.println(" *C");
  //delay(1000);
 
 //--------Servo Knob----------------
 
 val = analogRead(potpin);          // reads the value of the
                                    // potentiometer (value between
                                    // 0 and 1023)
 val = map(val, 0, 1023, 0, 179);   // scale it to use it with
                                    // the servo (value between 0 and
                                    // 180)
 myservo.write(val);                // sets the servo position according
                                    // to the scaled value
 delay(15);

  }

 //-----------Display-- -------------
 //float steinhart;
 display.showNumberDec(steinhart);  //Display the Variable value;
}
 
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