🛠 Mettre à jour le firmware du module radio (piège de désynchronisation)

Objectives

The LoRa module embeds a second microcontroller (STM32L0) whose AT firmware evolves independently from the SAMD core. The classic pitfall: "Firmware version mismatch" when a recent MKRWAN library encounters an older firmware (issue #126). This tutorial updates the module cleanly.

Hardware

• 1 Arduino MKR WAN 1300
• Either the MKRWANFWUpdate_standalone example (firmware binaries are embedded in the sketch), or a second Arduino for the FWUpdaterBridge
• MKRWAN library + arduino/mkrwan1300-fw repository (reference)

Complete Code

// Etape 1 — lire la version courante :
#include <MKRWAN.h>
LoRaModem modem;
void setup {
  Serial.begin(115200); while (!Serial) {}
  if (!modem.begin(EU868)) {
    Serial.println("Module muet : firmware corrompu ?"); while (1) {}
  }
  Serial.print("firmware actuel = ");
  Serial.println(modem.version);   // comparer aux releases du depot fw
}
void loop {}

// Etape 2 — mise a jour :
// Ouvrir File > Examples > MKRWAN > MKRWANFWUpdate_standalone,
// coller les binaires du firmware dans l'onglet, televerser, ouvrir le
// moniteur et suivre la progression. Alternative : FWUpdaterBridge avec
// un second Arduino cable en SPI sur le module.

Expected Verification

After the update, modem.version displays the current release and the messages "Failed to start module" / "Firmware version mismatch" disappear. The OTAA examples run normally again.

Common Errors

• Updating the library without the firmware (or vice versa): desynchronization — always align both.
• Known bug in arduino_read within MKRWANFWUpdate_standalone (issue #134): if the progress stalls, rewire or switch to FWUpdaterBridge.
• Wrong band binary (EU vs US): the module restarts in a loop.
• Confusing this with the SAMD bootloader: here we only flash the module's STM32L0.