Tag Archives: dash-cam

Bluetooth Trigger for Dash-Cam

Last week, I wrote about my experience using an old Droid X as a dash-cam, Russia-style. With Tasker and DailyRoads Voyager, the implementation allowed for completely hands-off operation; recording video only when the car was on.  The only issue was that I had needed to use the power source as the trigger for letting Tasker know when the car was operating.  This was fine until Winter struck here in Michigan, spelling doom for the battery, even with Airplane mode engaged.

I had the capability to run continuous power to the phone from the car’s own battery, but then what would trigger Tasker?  I had thought about trying to make something work with the GPS, or even a relay, but each had its pitfalls or inconsistencies.  Fortunately, Slickdeals offered a solution to the problem when Best Buy held a fire-sale for the Rocketfish Bluetooth Speaker for iPad.  $5 you say?  I’ll take 3!

A bit of dis-assembly later, and I was left with this:

Disassembly required.

Disassembly required.

Now, there is nothing too special about this specific product.  I imagine any Bluetooth audio device – including headsets – would work for the task, provided that it do three things:

  1. After removing the included battery, it must still power up and attempt to connect when USB power is attached.
  2. Pairing settings must be saved when power is removed – despite the lack of battery.
  3. If you decide to leave the battery attached, it must still power down immediately after power is removed, without any button presses required.


I suspect many Bluetooth devices will meet these requirements, but I can only vouch for the one I tried.


Bluetooth audio receiver module, Rocketfish RF-TRSPIPAD

So, once you have the board and are satisfied that it will function properly, it must be connected to a USB car adapter that powers on/off with the car.  Pair the phone up with the Bluetooth device, and create a Tasker profile to start DailyRoads Voyager when a pairing is made.  I have made my profile available below.


And it’s as simple as that.  No more dead batteries, and everything works just as well as before.  I noticed no lag at all in detecting the Bluetooth connection, even after days of it being powered off.  It is also worth mentioning that there has been no noticeable impact on the car’s battery, despite the phone running all the time with the radios on (but screen off).

100% hands-off operation, working flawlessly.

100% hands-off operation, working flawlessly.

Android Dash-Cam DIY


The gadgets in my car have been through a number of iterations, from TomTom running on an old Windows Mobile 6 phone, to a full-fledged, Windows 7 based CarPC complete with touchscreen, GPS and Bluetooth OBD-II data monitoring.  These were fun projects, and may be worth a future post.  Sadly, each had a number of flaws, and have since been replaced with a much simpler android setup.


My current electronics suite: a Droid X and a Whistler XTR-150 Laser/Radar Detector

Having no better use for my retired Motorola Droid X, I decided to re-purpose it as a dedicated Car DVR after watching one too many YouTube videos involving Russian motor vehicle accidents.  Why does a former superpower dominate this genre of video clips?  Surprisingly, Russia does not top the statistics when it comes to fatal motor vehicle accidents (the Middle East seems to dominate that field) and while they place a respectable 4th in alcohol consumption per capita, this by itself doesn’t seem to explain the need for meticulous video record-keeping of one’s daily commute to work.

Of course, the reason most of us keep records usually has something to do with taxes and the law, and it is no different here.  Apparently, the legal atmosphere on Russia’s roads is very much one of guilty-until-proven-innocent.  With widespread corruption, hit-and-runs, and the general dearth of witnesses, the Dash-Cam is a technological last hope for innocent drivers who are tired of being taken advantage of by accident-staging and bullying.

Here in Michigan, its more just for fun – although you never know when having footage on hand may prove useful.  So, how do you turn an old android smartphone into an automated, HD-video-shooting piece of awesomeness?


1) The phone.  Generally, any android phone will do for this, though you will want to be sure the camera placement is in a suitable location so as not to be blocked by the mount.  I’d aim for something that records in at least 720p, such as the Droid X, 1st-gen Galaxy S, or HTC Rhyme/Incredible/Desire.  A MicroSD slot is also highly recommended.

2) Get a mount.  I used this one from Arkon.  It is universal, cheap, and (aside from coming lose on a hot day), dependable.  This may be a better option, depending on where your camera is located.


3) Time to go shopping…at the Play Store.  You’ll need DailyRoads Voyager (free) and Tasker ($6.49).  Optionally, you can add (all free) Orientation ControlNo Lock, MyTracks (and its Tasker plugin), and Quick Boot to log GPS tracks and keep the screen unlocked and in landscape mode.  Rooting your device will unlock some extra functionality with Tasker, but isn’t strictly necessary for the task at hand.

4) Power.  You need a power source from your car to charge the phone.  It must only supply power when the car is on (most outlets do this).  A cheap car adapter will do, or you can get a bit more creative and splice in the wiring so as to conceal the wiring and make things look more professional.

5) Configuration.  Set up DailyRoads to automatically record (I like 5min clips) when launched.  Make sure to go through the rest of the settings and tweak them to your needs and the capabilities of your device.  Ensure the GPS data is logged in .srt format, as this will allow it to be overlayed on the video as subtitles when playing back on your PC with VLC or similar.

For Tasker, you’ll need it to launch DailyRoads (and MyTracks) when the car is powered on (charging), and kill it when power is removed, as well as switch to airplane mode to conserve battery.  Tasker can be a bit daunting the first time you open it up, but there are many guides online that walk you through its array of functions.  In addition, I have shared my profiles here, an you may import and modify them to suit your purposes.


That’s it!  Your Android Dash-Cam will now start and stop recording in tune with your driving, no input required.


car_lower_dash Having had this setup running for a bit over a half of a year, my biggest issue remains that of battery life.  Despite the power savings afforded by Airplane mode, I still find myself having to charge the phone manually about once per week, especially in the winter.  Ideally, I’d just run a cable to the phone that is always powered by the car’s battery – the small drain shouldn’t pose a threat to the car.  However, the issue here is that Tasker depends on the charging status to know when you’re driving. One idea is to use the GPS to measure speed, and have that trigger Tasker.  In my set-up though, the GPS is turned off with the car to save power, and even if I were to leave it on, I’m not confident that it would reliably maintain a fix for days on end.

That leaves Bluetooth and Wi-Fi as the only other input options.  I’m thinking of using a Bluetooth device  powered by the car to trigger the event when it connects to the phone.  When the car turns off, it will lose power, disconnect, and thus Tasker will know to stop the recording.  I’ll try to give both these options a fair shot in the next few weeks, and will report back if successful.

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