Send a simple HTTP request to REST API over Wifi with ESP32

SimpleRequestToRestApiOverWifi.uno.c

#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
 
void setup() {
 
  Serial.begin(115200);
  while (!Serial) delay(100);
 
  WiFi.begin("SSID", "P4ssw0rd");
  while (WiFi.status() != WL_CONNECTED) delay(500);
  Serial.println("Connected.");
}
 
void loop() {
 
  if (WiFi.status() == WL_CONNECTED) {
 
    HTTPClient http;
 
    // https://docs.kraken.com/api/docs/rest-api/get-ticker-information
    http.begin("https://api.kraken.com/0/public/Ticker?pair=XXBTZEUR");
 
    int httpCode = http.GET();
 
    if (httpCode == HTTP_CODE_OK) {
 
      String response = http.getString();
 
      JsonDocument doc;
      DeserializationError error = deserializeJson(doc, response);
      if (error) {
        Serial.print(F("deserializeJson() failed: "));
        Serial.println(error.f_str());
      } else {
        Serial.print("BTC: ");
        Serial.println(doc["result"]["XXBTZEUR"]["c"][0].as<double>());
      }
 
    } else {
 
      Serial.printf("failed, error: %i %s\n", httpCode, http.errorToString(httpCode).c_str());
 
    }
 
    http.end();
 
  } else {
 
    Serial.println("Network unreachable");
 
  }
 
  delay(5000);
}