Hi.
 
I think there was an update on the library.
 
I think that now you should declare the json doc as follows:

JsonDocument doc; 

instead of

StaticJsonDocument<1024> doc; 

 
Let me know if that fixes the issue.
 
If so, I’ll update the codes.
 
Regards,
Sara

Hi,
I tried changing the instruction to JsonDocument doc; as you said
The syntax errors that were shown earlier related to StaticJsonDocument <1024> doc;  are now fixed, but the return type error [Werror=return-type] still exists. 

Hi.
What line of code is giving you that error?
Regards,
SAra

Hi,
I solved the problem, but in a different way. I think the problem is because the function return String variable was not supported, I am not sure. 
I changed the function type for String getDateTime as Void getDateTime (that don’t have return value) and assigned the received JsonDocument datetime value to the variable requestData from the function loop itself. 

#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
 
// Replace with your network credentials
const char* ssid = “xxxxxx”;
const char* password = “xxxxxxxx”;
 
// Specify the timezone you want to get the time for: https://worldtimeapi.org/api/timezone/
const char* timezone =  “Asia/Calcutta”;//”Europe/Lisbon”;
// API endpoint
String url = String(“http://worldtimeapi.org/api/timezone/&#8221;) + timezone;
 
String currentDate;
String currentTime;
 
// Store hour, minute, second
int hour;
int minute;
int second;
 
// Store the result from the API request
String requestData = “failed”;
 
String formatTime(int time) {
  return (time < 10) ? “0” + String(time) : String(time);
}
  void getDateTime() {
   if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    // Construct the request
    http.begin(url);
    // Make the GET request
    int httpCode = http.GET();
    if (httpCode > 0) {
      // Check for the response
      if (httpCode == HTTP_CODE_OK) {
        String payload = http.getString();
        Serial.println(“Time information:”);
        Serial.println(payload);
        // Parse the JSON to extract the time
        JsonDocument doc;
        DeserializationError error = deserializeJson(doc, payload);
        if (!error) {
          const char* datetime = doc[“datetime”];          
          // Split the datetime into date and time
          requestData =datetime;
        }
        else {
          requestData =“failed”;
        }
       }
    }
}
 
void setup() {
  Serial.begin(115200);
  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  Serial.print(“Connecting”);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(“.”);
  }
  Serial.print(“\nConnected to Wi-Fi network with IP Address: “);
  Serial.println(WiFi.localIP());
 
  while(requestData == “failed”) {
 //requestData = getDateTime();
 getDateTime();
  }
 
  int splitIndex = requestData.indexOf(‘T’);
  // Extract date
  currentDate = requestData.substring(0, splitIndex);
  Serial.println(“Current Date: “ + currentDate);
 
  // Extract time
  currentTime = requestData.substring(splitIndex + 1, splitIndex + 9);
  Serial.println(“Current Time: “ + currentTime);
 
  // Extract hour, minute, second
  hour = currentTime.substring(0, 2).toInt();
  minute = currentTime.substring(3, 5).toInt();
  second = currentTime.substring(6, 8).toInt();
  Serial.println(“Hour: “ + String(formatTime(hour)));
  Serial.println(“Minute: “ + String(formatTime(minute)));
  Serial.println(“Second: “ + String(formatTime(second)));
}
 
void loop() {
 
}
 

Hi.
This issue was already resolved with Rui via email.
We’ll update the eBook with the new code.
You can check the new code here: https://github.com/RuiSantosdotme/Learn-ESP32-eBook/blob/main/Module_5/5_3_1_HTTP_GET_WorldTimeAPI/5_3_1_HTTP_GET_WorldTimeAPI.ino 
Regards,
Sara
 

Thanks, my pleasure. 

Great.
I’ll mark this issue as resolved. If you need further help, you just need to open a new question in our forum.
Regards,
Sara