ISS tracker project Arduino IDE code not working

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lyxm8d

Joined Sep 10, 2022
4
I'm attempting the following project:
https://create.arduino.cc/projecthu...ime-satellite-orbit-follower-tracker-w-5ef735

I've connected everything up properly, all of the components are working. I've uploaded the code to the arduino uno, changing what I think needs to be changed, but the red LED (meaning the ISS is out of range) is on constantly, even when I've changed the current time in the code to when the ISS should be overhead.
I don't have much experience with coding so I'm not sure if there's something I've missed or something else I need to add. I think it's possibly a problem with the integers epos and apos being set to equal zero, as this is what causes the red LED to turn on. This is the code I used (with the changes I've made):
C:
#include <TimeLib.h>
#include <ArduinoP13.h>
#include <Servo.h>

Servo elevation;
Servo azimuth;

// Current UTC [NOT LOCAL TIME]
int CurrentHour   = 20;
int CurrentMin    = 20;
int CurrentSec    = 00;
int CurrentDay    = 22;
int CurrentMonth  = 9;
int CurrentYear   = 2022;

// Set TLEs of your desired Satellite
const char *tleName = "ISS";
const char *tlel1   = "1 25544U 98067A   22264.34024677  .00027245  00000+0  48016-3 0  9990";
const char *tlel2   = "2 25544  51.6428 220.2201 0002499 280.2153 244.2840 15.50209155360097";



// Set your Callsign and current location details
const char  *pcMyName = "S21TO";     // Observer name
double       dMyLAT   = +53.415150;    // Latitude (Breitengrad): N -> +, S -> -
double       dMyLON   = -2.917480;    // Longitude (Längengrad): E -> +, W -> -
double       dMyALT   = 67;        // Altitude ASL (m)




int rangePin = 7;   // LED for in Range Indication
int NrangePin = 6;  // LED pin for Out of range indication


int epos = 0; 
int apos = 0;

double       dSatLAT  = 0;           // Satellite latitude
double       dSatLON  = 0;           // Satellite longitude
double       dSatAZ   = 0;           // Satellite azimuth
double       dSatEL   = 0;           // Satellite elevation

char         acBuffer[20];           // Buffer for ASCII time



void setup()
{
  setTime(CurrentHour,CurrentMin,CurrentSec,CurrentDay,CurrentMonth,CurrentYear);

  elevation.attach(9);
  azimuth.attach(10);

  elevation.write(epos);
  azimuth.write(apos);

  pinMode(NrangePin, OUTPUT);
  pinMode(rangePin, OUTPUT);

  Serial.begin(9600);
  delay(10);

  digitalWrite(NrangePin, HIGH);
  digitalWrite(rangePin, HIGH);
  delay(5000);
  }


void loop()
{

  char buf[80]; 

  int i;
  int          iYear    = year(2022);        // Set start year
  int          iMonth   = month(9);       // Set start month
  int          iDay     = day(22);         // Set start day
  int          iHour    = hour(14);        // Set start hour [ substract -6 from current time ]
  int          iMinute  = minute(20);      // Set start minute
  int          iSecond  = second(0);      // Set start second



  P13Sun Sun;                                                       // Create object for the sun
  P13DateTime MyTime(iYear, iMonth, iDay, iHour, iMinute, iSecond); // Set start time for the prediction
  P13Observer MyQTH(pcMyName, dMyLAT, dMyLON, dMyALT);              // Set observer coordinates

  P13Satellite MySAT(tleName, tlel1, tlel2);                        // Create ISS data from TLE

  MyTime.ascii(acBuffer);             // Get time for prediction as ASCII string
  MySAT.predict(MyTime);              // Predict ISS for specific time
  MySAT.latlon(dSatLAT, dSatLON);     // Get the rectangular coordinates
  MySAT.elaz(MyQTH, dSatEL, dSatAZ);  // Get azimut and elevation for MyQTH

  Serial.print("Azimuth: ");
  Serial.println(dSatAZ,2);
  Serial.print("Elevation: ");
  Serial.println(dSatEL,2);
  Serial.println("");



  delay(500);


  // Servo calculation
  epos = (int)dSatEL;
  apos = (int)dSatAZ;

  if (epos < 0) {
      digitalWrite(NrangePin, HIGH);
      digitalWrite(rangePin, LOW);
  } else {
      digitalWrite(NrangePin, LOW);
      digitalWrite(rangePin, HIGH);

      if(apos < 180) {
        apos = abs(180 - (apos));
        epos = 180-epos;

      } else {
        apos = (360-apos);
        epos = epos;
      }
      azimuth.write(apos);
      delay(15);   
      elevation.write(epos);        
  }
}
Is there a specific reason why it isn't working? Is there anything I should've changed with the code?

Any help would be appreciated:)

Mod edit: code tags. JohnInTX
 
Last edited by a moderator:

sagor

Joined Mar 10, 2019
757
The year, month, etc. functions do not take arguments when assigning to a variable, but use current internal Arduino device time. I think those functions are related to some RTC function (set time then read time).
That is, you can use:
year(2022) to set the year or
int iyear = year() to return the current year value

but not both at the same time....
I may be wrong on this. Try the original code with the "current" values set to what you want and see if the original code works with tracking.
 

upand_at_them

Joined May 15, 2010
940
Did you get the latest TLE? They have to be updated every so often, because they're not perfect. Here's the latest:

1 25544U 98067A 22267.86615728 .00008592 00000+0 15693-3 0 9992
2 25544 51.6423 202.7405 0002297 288.7348 126.2340 15.50259419360641

Are you checking the prediction with the online ISS tracker?
 
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