Listen, Coppertop

So recently we had noticed that randomly, some customer’s GPS trackers would alarm that their internal battery was at zero volts, and then immediately say in the next GPS record that everything was groovy.

That was a new one. Why would the GPS tracker battery report as zero volts and then immediately say it was fully charged in the next GPS record? We couldn’t pin it down, mostly due to other priorities, but it stayed as an itch inside my mind.

And then it happened to ME!

Well now, challenge accepted. We pulled all of the debug logs from the tracker and compared the logs to what our GPS server saw. As it turns out, if a GPS tracker ever does a reboot due to concerns it has with the mobile network (which definitely can happen when the telcos get a bit handsy as part of their congestion management strategies), there is a dice roll chance that the first record it uploads to our servers has not yet managed to measure the internal battery voltage.

And so we get a GPS record with zero volts recorded for the internal battery, which triggers a Low Battery alarm from our server. Maybe it was fine. Maybe folks were getting one at 3am. 😐

That is…less than optimal for the customer experience.

NOW who’s getting Handsy?

A little bit of tweaking of our battery alarm logic, and the problem is resolved. Now our server sees that zero volts and takes a quick look back in time to see what the last voltage reading was. If it’s a sudden drop to zero in one record only, we filter that noise out.

Anyone else a fan of The Matrix? Took me years to work out why she called Neo a “Coppertop”!