Continuous session won't reopen after brownouts (stuck at connected-closed)

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Hi all,

I’ve got a Notecard (NOTE-MBGLW, firmware 11.3.1.17696) on a Notecarrier X v1.2, talking to a Raspberry Pi 5 over I2C. hub.set is mode continuous with sync:true, so commands we add to
commands.qi from the Notehub API show up in a couple seconds. That was working fine earlier today, sessions were staying open 20-30 min at a time.

Then I had power problems. The card was on a bench supply at 3.7V on VBAT and it was sagging when the radio kicked on, so the card kept resetting (and jamming the Pi’s I2C bus each
time). I bumped the supply to 4.2V and the resets stopped, but now the card won’t go back to a continuous session.

hub.status just sits at “connected {connected-closed}” and hub.sync.status says “connected {connected-closed} {transport}” with mode {modem-on}. Signal is fine (AT&T LTE, 2 bars, SINR
around 14). In Notehub I only see short “first sync” sessions, like 3-8 seconds, closed by the notecard, nothing marked continuous.

Things I tried:

  • hub.sync: shows as requested, but nothing shows up in Notehub
  • hub.sync with allow:true: same
  • switching hub.set to periodic and back to continuous: no change
  • card.restart: connects in about 45s, does one quick first sync, then goes right back to connected-closed

So a few questions:

  • What does {connected-closed} {transport} actually mean when you’re in continuous mode?
  • Could the card be in some kind of backoff after all the resets? Is there a way to check or clear that?
  • Is there a better way to recover the session from the host than card.restart?
  • For getting commands down in a few seconds, is continuous + sync:true the right setup, or should I be using something else?

Thanks!

2

Hi @Sonny_Chen and welcome to the Blues community!

Thanks for sending all of this detail. So, I don’t think this is backoff from the resets. Are you using the GPS module at all? Because it almost looks like Notecard’s onboard GPS is holding the modem, and on the Notecard GPS and cellular can’t run at the same time.

To answer your other questions: {connected-closed} means the modem is on and registered with the network, but has no data connection, so no Notehub session can be open. It’s also probably not a penalty box, as a network penalty box would add {registration-failure} or {network} to the status.

So if you run:

{"req":"card.location"}

…and the status shows {gps-active} or “GPS search…”, then GPS is probably the cause.

Let me know!
Rob