Hi,
As you will see in my code, I’m a programming noob so please bare with me 
The goal of my project is to fetch weather data and display it on an LCD screen. Here I have removed code that is not needed to show my problem.
I am aware that my project can be solved in many different ways but I’m doing it this way to learn OOP in Arduino. I’ve created the following classes:
class WeatherData - Purpose: To hold weather data to reuse data when needed. A struct could probably do it but wants to learn Arduino OOP.
class OpenWeatherMap - Purpose: To connect to Open Weather Map API and fetch weather data. This does not has be a class but again I’m using this to learn how to use Arduino OOP.
As you will see, The OpenWeatherMap class is creating an instance of the WeatherData class, fetching data from the API and storing it in the WeatherData instance, I’m in my sketch I’m creating an instance of the OpenWeatherMap class getting the data and storing it two different instances of the WeatherData class.
If I only create one instance everything works just fine but if I create two objects the data in the second object is not correct, seems like the same memory is used and the data is overwritten in the second object.
Project can be found here: https://github.com/datamann/OopBestPractices
/OopBestPractices.ino/
#include <SPI.h>
#define DEBUG
#include "openweathermap.h"
#include "wifi.h"
String apikey = "***";
OpenWeatherMap owp;
OpenWeatherMap owp1;
WeatherData Ilagan;
WeatherData Drammen;
void setup() {
Serial.begin(9600);
/*Code removed: maximum allowed length (9000 char).*/
}
#ifdef DEBUG
Serial.print(F("\n\nWiFi connected: "));
Serial.println(WiFi.localIP().toString());
#endif
Ilagan = owp.fetchWeatherData("1711146", apikey);
Drammen = owp1.fetchWeatherData("3159016", apikey);
/*Code removed: maximum allowed length (9000 char).*/
}
void loop() {
}
/WeatherData.h/
#ifndef WEATHERDATA_h
#define WEATHERDATA_h
class WeatherData {
public:
WeatherData();
void setLocation(const char* location);
const char* getLocation();
void setTemperature(float temperature);
float getTemperature();
void setFeelslike(float feelsLike);
float getFeelslike();
void setTemp_min(float temp_min);
float getTemp_min();
void setTemp_max(float temp_max);
float getTemp_max();
void setPressure(int pressure);
int getPressure();
void setHumidity(int humidity);
int getHumidity();
void setWeather(const char* weather);
const char* getWeather();
void setDescription(const char* description);
const char* getDescription();
void setWindspeed(float windSpeed);
float getWindspeed();
void setWinddirection(int windDirection);
int getWinddirection();
void setWindcompassdirection(const char* windCompassDirection);
const char* getWindcompassdirection();
void setWeatherid(int weatherID);
int getWeatherid();
void setTimes(const char* timeS);
const char* getTimes();
private:
const char* _location;
float _temperature;
float _feelsLike;
float _temp_min;
float _temp_max;
int _pressure;
int _humidity;
const char* _weather;
const char* _description;
float _windSpeed;
int _windDirection;
const char* _windCompassDirection;
int _weatherID;
const char* _timeS;
};
#endif
/WeatherData.cpp/
#include "WeatherData.h"
WeatherData::WeatherData() {
_location = "--";
_temperature = 0.00;
_feelsLike = 0.00;
_temp_min = 0.00;
_temp_max = 0.00;
_pressure = 0;
_humidity = 0;
_windSpeed = 0.00;
_windDirection = 0;
_weatherID = 0;
};
void WeatherData::setLocation(const char* location) {
_location = location;
};
const char* WeatherData::getLocation() {
return _location;
};
void WeatherData::setTemperature(float temperature) {
_temperature = temperature;
};
float WeatherData::getTemperature() {
return _temperature;
};
void WeatherData::setFeelslike(float feelsLike) {
_feelsLike = feelsLike;
};
float WeatherData::getFeelslike() {
return _feelsLike;
};
void WeatherData::setTemp_min(float temp_min) {
_temp_min = temp_min;
};
float WeatherData::getTemp_min() {
return _temp_min;
};
void WeatherData::setTemp_max(float temp_max) {
_temp_max = temp_max;
};
float WeatherData::getTemp_max() {
return _temp_max;
};
void WeatherData::setPressure(int pressure) {
_pressure = pressure;
};
int WeatherData::getPressure() {
return _pressure;
};
void WeatherData::setHumidity(int humidity) {
_humidity = humidity;
};
int WeatherData::getHumidity() {
return _humidity;
};
void WeatherData::setWeather(const char* weather) {
_weather = weather;
};
const char* WeatherData::getWeather() {
return _weather;
};
void WeatherData::setDescription(const char* description) {
_description = description;
};
const char* WeatherData::getDescription() {
return _description;
};
void WeatherData::setWindspeed(float windSpeed) {
_windSpeed = windSpeed;
};
float WeatherData::getWindspeed() {
return _windSpeed;
};
void WeatherData::setWindcompassdirection(const char* windCompassDirection) {
_windCompassDirection = windCompassDirection;
};
const char* WeatherData::getWindcompassdirection() {
return _windCompassDirection;
};
void WeatherData::setWinddirection(int windDirection) {
_windDirection = windDirection;
};
int WeatherData::getWinddirection() {
return _windDirection;
};
void WeatherData::setWeatherid(int weatherID) {
_weatherID = weatherID;
};
int WeatherData::getWeatherid() {
return _weatherID;
};
void WeatherData::setTimes(const char* timeS) {
_timeS = timeS;
};
const char* WeatherData::getTimes() {
return _timeS;
};
/openweathermap.h/
#ifndef OPENWEATHERMAP_h
#define OPENWEATHERMAP_h
#include "WeatherData.h"
class OpenWeatherMap {
public:
OpenWeatherMap();
WeatherData fetchWeatherData(String cityid, String apikey);
private:
const char* getWindDirection(int deg);
bool inRange(float val, float minimum, float maximum);
char* _servername = "api.openweathermap.org";
WeatherData *wd;
};
#endif
/openweathermap.cpp/
#include "openweathermap.h"
#include "WeatherData.h"
#include <ArduinoJson.h>
#include <WiFi.h>
OpenWeatherMap::OpenWeatherMap() {
wd = new WeatherData();
};
WeatherData OpenWeatherMap::fetchWeatherData(String cityid, String apikey)
{
String result = "";
WiFiClient client;
const int httpPort = 80;
if (!client.connect(_servername, httpPort)) {
#ifdef DEBUG
Serial.print(F("Client not connected! "));
Serial.println(client);
#endif
}
String url = "/data/2.5/forecast?id="+ cityid +"&units=metric&cnt=1&APPID="+ apikey;
client.print(String("GET ") + url + " HTTP/1.1\r\n" +
"Host: " + _servername + "\r\n" +
"Connection: close\r\n\r\n");
unsigned long timeout = millis();
while (client.available() == 0) {
if (millis() - timeout > 10000) {
client.stop();
#ifdef DEBUG
Serial.print(F("Client timed out! "));
Serial.println(client);
#endif
}
}
while(client.available()) {
result = client.readStringUntil('\r');
}
result.replace('[', ' ');
result.replace(']', ' ');
char jsonArray [result.length()+1];
result.toCharArray(jsonArray,sizeof(jsonArray));
jsonArray[result.length() + 1] = '\0';
StaticJsonDocument<1024> doc;
DeserializationError error = deserializeJson(doc, jsonArray);
if (error) {
#ifdef DEBUG
Serial.print(F("deserializeJson() failed with code "));
Serial.println(error.c_str());
#endif
}
const char* location = doc["city"]["name"];
wd->setLocation(location);
float temperature = doc["list"]["main"]["temp"];
wd->setTemperature(temperature);
float feelsLike = doc["list"]["main"]["feels_like"];
wd->setFeelslike(feelsLike);
float temp_min = doc["list"]["main"]["temp_min"];
wd->setTemp_min(temp_min);
float temp_max = doc["list"]["main"]["temp_max"];
wd->setTemp_max(temp_max);
int pressure = doc["list"]["main"]["pressure"];
wd->setPressure(pressure);
int humidity = doc["list"]["main"]["humidity"];
wd->setHumidity(humidity);
const char* weather = doc["list"]["weather"]["main"];
wd->setWeather(weather);
const char* description = doc["list"]["weather"]["description"];
wd->setDescription(description);
float windSpeed = doc["list"]["wind"]["speed"];
wd->setWindspeed(windSpeed);
int windDirection = doc["list"]["wind"]["deg"];
wd->setWinddirection(windDirection);
wd->setWindcompassdirection(getWindDirection(wd->getWinddirection()));
int weatherID = doc["list"]["weather"]["id"];
wd->setWeatherid(weatherID);
return *wd;
};
const char* OpenWeatherMap::getWindDirection(int deg)
{
float wind_deg = float(deg);
const char* direction = "---";
if(OpenWeatherMap::inRange(wind_deg, 348.750, 360.999)){direction = "N";return direction;}
/*Code removed: maximum allowed length (9000 char).*/
};
bool OpenWeatherMap::inRange(float val, float minimum, float maximum)
{
return ((minimum <= val) && (val <= maximum));
};
