🛠 Scanner les réseaux WiFi et se connecter en station

Objectives

Use the WiFiNINA library to control the u-blox NINA-W102 radio module (an ESP32 reprogrammed by Arduino): list nearby networks with WiFi.scanNetworks, then join a WPA2 access point in station mode and display the obtained IP address. This is the foundation of all network tutorials in this series.

Hardware

• 1 × Arduino MKR WiFi 1010
• A 2.4 GHz WiFi network (the NINA does not see 5 GHz)
• Arduino IDE with the SAMD core and the WiFiNINA library installed
• Up-to-date firmware on the NINA module (see the "NINA firmware update" tutorial)

Complete Code

#include <WiFiNINA.h>

const char* SSID = "votre-ssid";
const char* PASS = "votre-mot-de-passe";

void setup {
  Serial.begin(115200);
  while (!Serial && millis < 3000);

  int n = WiFi.scanNetworks;
  Serial.printf("%d reseaux trouves\n", n);
  for (int i = 0; i < n; i++)
    Serial.printf("%s (%d dBm)\n", WiFi.SSID(i).c_str, WiFi.RSSI(i));

  Serial.print("Connexion...");
  WiFi.begin(SSID, PASS);
  while (WiFi.status != WL_CONNECTED) { delay(500); Serial.print("."); }
  Serial.printf("\nConnecte ! IP: %s\n",
                WiFi.localIP.toString.c_str);
}

void loop {
  if (WiFi.status != WL_CONNECTED) {
    Serial.println("Reconnexion...");
    WiFi.reconnect;
  }
  delay(2000);
}

Expected Verification

The serial monitor displays the list of SSIDs with their power in dBm, then the local IP address (typically 192.168.x.x) after a few progress dots. If you cut the WiFi connection on the router, the sketch displays "Reconnecting..." and re-establishes the link when the connection returns.

Common Errors

• WiFi.begin returns/remains in status 255: almost always due to outdated or incompatible NINA firmware with the WiFiNINA version — update the module via the Firmware Updater in IDE 2.
• 5 GHz network: the NINA-W102 is 2.4 GHz only, so the 5 GHz SSID will never appear in the scan.
• Accented characters or symbols in the password: due to encoding issues, test first with an ASCII password.
• Static IP with WiFi.config before WiFi.begin: historically ignored (WiFiNINA bug #5, DHCP won) — check your library version before relying on this.