Boron 404X Device Disconnects and Fails to Reconnect – Advice Wanted

Connectivity Cellular
1

Hi all,

I’m dealing with a persistent issue involving a Boron 404X running Device OS 6.2.1, deployed in a low-signal area in Florida. While reception isn’t great, it’s not a complete dead zone. The device connects to the Particle Cloud upon boot, but after some time, it disconnects and never reconnects on its own. It remains offline for days unless manually power-cycled.

In my code, I’m using:

  • SYSTEM_THREAD(ENABLED)
  • SYSTEM_MODE(AUTOMATIC)
  • Particle.connect() is called in setup()

This exact firmware has been deployed to other devices in areas with stronger signal. Those units have occasionally disconnected, but they successfully reconnected on their own without issue.

The last reported metrics from the problematic device were:

  • Signal strength: 55%
  • Signal quality: 29%

Not great, but in my opinion, still within a range where reconnection should be possible.

My Questions:

  • Since I’m already calling Particle.connect() in setup() and using SYSTEM_MODE(AUTOMATIC), should I be explicitly calling Particle.connect() again elsewhere in the code to help trigger reconnection?
  • Does automatic mode handle all reconnection logic, or does it eventually stop retrying under poor conditions?
  • Are there any known LTE reconnection timeout limits or behaviors I should be aware of?
  • Is there any way to log or monitor this behavior remotely? I don’t have physical access to the unit as I’m in a different state.

Would love any advice from anyone who’ve seen similar behavior or have tips for maintaining connectivity in borderline signal areas.

Thanks!

2

You should try Device OS 6.3.3, which is now a GA release.

If you can connect a laptop to a device in a bad signal zone, enable logging and save the USB serial log.

SerialLogHandler logHandler(LOG_LEVEL_TRACE);

The device will always automatically reconnect if possible, so the log will be helpful to determine why it can't reconnect.

Since your problem may be signal strength related there may be a different cause in your case, but the most common reason a device will not reconnect but will immediately reconnect after hitting the reset button is that the firmware has a memory leak and it has run out of memory. See out of memory handler.

3

Hi,
What if you would add some code that after, say, one hour of being offline, it resets the device?