Bus Fault (Four Red Flashes)


In all the troubleshooting documentation so far, I’ve only found 4 Red Flashes (four red flashes in between the SOS red flashes) = “Bus Fault” but no explanation of what it means and how to potentially fix.

What does “Bus Fault” actually mean and how can it be debugged/fixed ?

Currently my photon device does this at different points in the code (but always within or before a specific function call).

Any help would be appreciated,



I think the confusion might be that bus fault in this case is more commonly referred to as a bus error. That may have thrown you off the trail a bit. Our documentation is a little lean on describing what this is.

Typically a bus error arises when code is trying to access an address that doesn’t exist (possibly something out of bound) or is trying to use a freed pointer. I would check your code and logs for anything around memory handling to see if there’s something going on there.

If you are comfortable sharing it, you could also post your code here for others to look at and help you spot the cause.