Bike, backpack, suitcase: the old phone as guard and tracker
A cheap second phone becomes a hidden alarm system with siren and GPS track for backpack, bike and suitcase. Setup and limits.
A bike is gone quickly, a suitcase vanishes in the crowd, a backpack gets left on the train. Bluetooth trackers exist for that, but they only show where another device nearby saw the tracker. A phone as a guard knows where it is itself and can raise the alarm as well.
What you need
A retired Android phone with a battery and, if it should work independently of Wi-Fi, a SIM card with a data plan. Prepaid plans with a small data allowance are enough: position reports use only a few kilobytes. In addition, the VintageCam Ultimate add-on, which is included in the first 14 days.
Setup in three steps
Start the app on the second phone, choose “Alarm system – backpack, car, bike” and give it a name, such as “Bike”. Allow location and set it to “Always”. Then you arm the alarm system. After the delay (25 seconds by default, adjustable) it is active. On your everyday phone you see its state and position in the viewer under “Protection & map”.
How the phone behaves
If it is lifted, shaken or moved, a shrill siren sounds, or alternatively only a silent message if you do not want to warn the thief. Meanwhile the phone reports its position frequently, about every 10 seconds while moving and less often at rest. On the map you see where it is moving, colour-coded by state. If it stays still for 25 seconds after the alarm, the siren stops, the system stays armed and sounds again on new movement.
Where to stow it
In the backpack it sits in an inner pocket, in the suitcase among the clothes, on the bike in a saddlebag. It should not lie in the sun and not be completely enclosed by metal, because that swallows GPS signals. Before first use, check that it reports position and alarm reliably.
Bikes in particular
A bike thief often lifts a bike first or carries it away. Both trigger the motion sensors. Mount the phone so that it is not conspicuous at first glance, but do not hide it purely for the sake of effect: a conspicuous siren can deter thieves, while a silent alarm helps to follow the location. Both can be set per trigger. And leave the recovery to the police, even if the map shows exactly where the bike is.
Battery and limits
A phone in guard mode lasts days to weeks, depending on the battery and settings, if it mostly lies still, because then it reports its position only every few minutes. Against theft the siren and the track help, but they are no miracle: if the phone is switched off, or discovered and removed, the tracking ends. Also read The honest limits and how to export the GPS track.
