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esp32_client_resp_api_webserver

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esp32_client_resp_api_webserver [2025/03/19 09:31] – created brunoesp32_client_resp_api_webserver [2025/03/19 09:48] (current) – bruno
Line 1: Line 1:
 +<code c++>
 +/* 
 +  Get the price of bitcoin from the Kraken API to an ESP32 platform and webserve it 
 +*/
  
 +#include <WiFi.h>
 +#include <HTTPClient.h>
 +#include <WebServer.h>
 +#include <ArduinoJson.h>
 +
 +WebServer server(80);
 +
 +void handleRoot() {
 +  server.send(200, "text/plain", "BTC");
 +}
 +
 +void handleNotFound() {
 +  server.send(404, "text/plain", "File Not Found");
 +}
 +
 +void setup() {
 +
 +  Serial.begin(115200);
 +  while (!Serial) delay(100);
 +
 +  WiFi.begin("ssid", "p4ssw0rd");
 +
 +  Serial.print("Connecting to WiFi... ");
 +  while (WiFi.status() != WL_CONNECTED) delay(500);
 +  Serial.println("Ok.");
 +  Serial.print("IP address: ");
 +  Serial.println(WiFi.localIP());
 +
 +  server.on("/", handleRoot);
 +
 +  server.onNotFound(handleNotFound);
 +
 +  server.begin();
 +  Serial.println("HTTP server started");
 +}
 +
 +void loop() {
 +
 +  /*
 +    freely inspired by:
 +    - BasicHTTPClient.ino from Espressif ESP32 Dev Module
 +    - https://arduinojson.org/v6/example/parser/
 +  */
 +  
 +  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");
 +    Serial.print("Send request... ");
 +
 +    // start connection and send HTTP header
 +    int httpCode = http.GET();
 +
 +    // httpCode will be negative on error
 +    if (httpCode > 0) {
 +
 +      Serial.println(httpCode);
 +
 +      // file found at server
 +      if (httpCode == HTTP_CODE_OK) {
 +        String response = http.getString();
 +        Serial.println(response);
 +
 +        // Use arduinojson.org/v6/assistant to compute the capacity.
 +        //DynamicJsonDocument doc(2048);
 +        JsonDocument doc;
 +        DeserializationError error = deserializeJson(doc, response);
 +        if (error) {
 +          // F -> https://www.locoduino.org/spip.php?article131 [FR]
 +          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: %s\n", http.errorToString(httpCode).c_str());
 +    }
 +    http.end();
 +  } else {
 +    Serial.println("Network unreachable");
 +  }
 +
 +  server.handleClient();
 +  delay(5000);
 +}
 +</code>