🛠 Client HTTPS/TLS : interroger une API sécurisée via le Murata 1DX

Objectives

Move from "connected" Wi-Fi to "useful" Wi-Fi: talk to a server over TLS (HTTPS). The Mbed core provides WiFiSSLClient, a TCP socket that automatically negotiates TLS encryption — trusted certificates are stored in the board's flash, which eliminates the need for a real-time clock for the handshake. You will build an HTTP/1.1 request by hand on this client, the basic pattern for consuming any API.

Hardware

• 1 × Arduino Portenta H7 + USB-C data cable
• Wi-Fi access point with Internet access
• "Arduino Mbed OS Portenta Boards" core; Secrets tab filled (SECRET_SSID, SECRET_PASS)
• Serial console at 115200 baud

Full code

// client_tls.ino — modele l'exemple WiFiSSLClient du core
#include <WiFi.h>
#include "arduino_secrets.h"

char ssid[] = SECRET_SSID;
char pass[] = SECRET_PASS;
int status = WL_IDLE_STATUS;

WiFiSSLClient client;        // TLS : pas d'RTC necessaire,
                             // le certificat est en flash

void setup {
  Serial.begin(9600);
  while (!Serial) {}

  if (WiFi.status == WL_NO_MODULE) {
    Serial.println("Module Murata 1DX non detecte !");
    while (true) {}
  }
  while (status != WL_CONNECTED) {
    Serial.print("Connexion a "); Serial.println(ssid);
    status = WiFi.begin(ssid, pass);
    delay(3000);
  }
  Serial.print("IP : "); Serial.println(WiFi.localIP);

  if (client.connect("www.google.com", 443)) {
    client.println("GET / HTTP/1.1");
    client.println("Host: www.google.com");
    client.println("Connection: close");
    client.println;
    while (client.available) Serial.write(client.read);
    client.stop;
  } else {
    Serial.println("Poignee de main TLS echouee");
  }
}

void loop {}

Expected verification

After the Wi-Fi connection, the TLS handshake runs (a few hundred ms — the 480 MHz machine performs the crypto calculations), then the page's HTML is displayed on the console. Replace the host with a JSON API for real-world usage: same lines, adapted Host header, then parse the response body.

Common errors

• Server with a self-signed certificate or incomplete chain: validation fails and connect returns false with little detail — test first with a public site with a valid certificate.
• >
• Chunked/gzip response: this example reads raw bytes; some APIs compress — add Accept-Encoding: identity to stay in plain text.
• Forgetting the Host header in HTTP/1.1: virtual hosts return a 400 error or the wrong site.
• Never calling client.stop: the remote server keeps the connection open and may refuse subsequent ones.
• Confusing with BLE: the Murata 1DX also supports Bluetooth 5.1 (Classic + LE, official tutorial ble-connectivity) — but for web APIs, it is indeed Wi-Fi + WiFiSSLClient.
• Captive networks (hotels, corporate Wi-Fi): WiFi.begin "connects" but TLS fails until the browser has validated the portal.