Homebrew Dash Cam Enables Full Suite of Sensors

You heard it here first: dash cams are going to be the next must-have item for your daily driver. Already reaching market saturation in some parts of the world but still fairly uncommon in North America, we predict that car makers will soon latch onto the trend and start equipping cars with dash cams as standard equipment. And you can just bet that whatever watered-down, overpriced feature set they come up with will be sure to disappoint, so you might want to think about building your own Raspberry Pi dash cam with an accelerometer and lots of LEDS.

Still very much in the prototyping phase, [CFLanger]’s project is at its heart a dash cam, but it looks like he wants to go far beyond that. Raspivid and a PI NoIR camera take care of the video streaming, but the addition of a Pi SenseHAT gives [CFLanger] a bunch of options for sensing and recording the car’s environment. Not content with the SenseHAT’s onboard accelerometer, he added an ADXL345 to the sensor suite. The 64-pixel LED display is just for fun – it displays pitch and roll of the platform – and a yet-to-be-implemented bar-graph display will show acceleration in the X-axis. He figures the whole thing is good for a couple of days of video, but we hope he adds audio capture and perhaps ECU data from an OBDII-Bluetooth adapter.

We’ve seen surprisingly few DIY dash cams on Hackaday, at least so far. There has been a dash cam teardown and retasking, and there are plenty of dashboard computer builds, though. Seems like most hackers want that DIY self-driving car first.

21 thoughts on “Homebrew Dash Cam Enables Full Suite of Sensors

  1. With that wimpy lens it will see jack shit if it’s not a bright sunny day…
    Either get the camera with the bigger lens already installed or hack it for an M12 fine thread and use one of the plethora of CCTV lenses ebay has to offer…

      1. A lot of them have much bigger lenses, because even Wang from the cost cutting department sometimes understands that it actually has to be able to see something…

        They’re fairly cheap lenses, (definitely not Carl Zeiss :D ), but they make a significant difference.

    1. Yes, but that seams like the easy part. Ideally it’ll be able to take multiple camera streams and limit itself only by whatever USB or wireless camera is available. At a min we’d be looking for forward and rear facing cameras, but a great aspect to a platform like this is the ability to add many more than that. Side facing, left/right turn cameras (already standard on many family vans), and of course a good angle for the CopBlock Cam. ;)

          1. It’ll help in that having an audit trail is far better then not. There’s an endless list of “what if”s for piece of evidence, but it’s still evidence and the other side will need to actually prove (not just infer) that it is somehow tainted or otherwise invalid.

            The fact it a trail of time-stamped GPS coordinates combined with a video log is a very difficult piece of combined evidence to fake. The GPS based speeds can be confirmed against known markers in the video footage, such as road markings, street signs, etc. It’s self-calibrating (because GPS) and self-validating.

            The cop’s equipment on the other hand…not near so certain. There’s a lot of room for error both in the cop’s use of the equipment as well as the calibration of the equipment itself. There is no method available to validate the readings, no second source of confirmation data.

            If it’s a GPS time-stamp log plus video log that says “no speeding” vs a C-graduate cop aiming his old radar gun one handed as he munches on a donut…

  2. “we predict that car makers will soon latch onto the trend and start equipping cars with dash cams as standard equipment.”

    There already are dash-cams that come standard in cars. They’re not for recording video, but rather for signage/object detection/recognition/distance measurement. The lower-class models have a mono camera which is only capable of detection and recognition. The vehicle has to be equipped with a front faced radar system to allow distance measurement. But that’s not as precise for smaller objects e.g. people. The higher-class models have a stereo camera (basically two cams in one unit) which can do everything without having to rely on a radar. Both systems are of course highly integrated into the rest of the car, making use of all available sensors.

    Making them record video is just a matter of adding storage and setting a flag in software.

  3. Educational yes, pratical?

    Is there anything easier/simple/cheaper and fast then buy a action cam for recording and download one (of many available) smartphone apps to get sensorial data? And you can always use the action cam in other situations opposed to the pycam..

    And if you like to learn, you can always code the app to suite your car and your smartphone :)

    1. An out-of-the-box dash cam is much better suited to the application than sticking a typical action cam to the windshield. Dash cams typically have software for continual recording, auto-start/auto-stop based on the vehicle’s power, and a sensor suite to stop overwriting and preserve a recording in case of a sudden acceleration/deceleration. An action cam usually needs a separate action to turn it on (meaning the human will forget it), it won’t overwrite files if the storage is full (the human has to change flash chips), and doesn’t have any accelerometers to detect crashes. All those things would have to be baked into an external control circuit for the action cam (or an RPi.)

  4. The problem with Stock cameras in the vehicle is who owns the recordings? Would they be subject to a warrant or would they be something that a police officer would be able to copy during a regular stop? How long would the recordings need to be maintained? Who would have access to the recordings? Just trying to figure out who is allowed to look at a vehicles event data recorder data can be a legal quagmire, add video to that and you have a big legal nightmare.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s