MKR FOX: SigFox messages stop after two successful messages

I have a script that has been running fine on my MKR FOX, which reads some sensor data and sends the results every 15 minutes via SigFox.

I recently had to upgrade to windows 10 ( and subsequently has to load the latest Arduino IDE and libraries again).

I recompiled the code and ported it to my MKR1200FOX. It starts OK but once its sent two messages it stops sending anymore.

It only seems to work if I add SigFox.debug() to the code;

Anyone else encountered something like this?

Hi Coastobs,
i have the same issues with my nodes. Recently i changed from a laptop to a desktop. Then i wanted deploy a new node, but after a few messages the device stops working. So i checked with a spare mkrfox with the same result.
I have several nodes around and never had a problem, so now im afraid to make firmwareupdates on them.

Have you found a solution for this issue???

But whats about battery life???


Enable debugging. Enabling the debugging all the power saving features are disabled and the led indicated as signaling pin (LED_BUILTIN as default) is used during transmission and receive events.

This solution worked for me also by using an external interrupt.


Dear all,

Thank you very much for your help. I was in the same situation in which the code stopped working after the second message package and before everything worked fine. After making the modifications in the library of the link you have sent, it now works perfectly as before.

I will finally stop having this problem that was driving me crazy. Thank you! :slight_smile:

Best regards

Hello everyone.

It seems to be a bug in non-debug mode.


you can read the following:

"You may note that I switch the Arduino Sigfox library in debug mode. This is basically needed because of a bug in non debugging mode. For real in non debugging mode the SAMD chip is switched to sleep mode waiting for Sigfox communication to terminate. But it never come back from this state. Sound like a bug in the Arduino LowPower library once your have made an USB sketch upload it seems the LowPower.sleep() function never come back."