Automated Magnetic Cell Phone Mount

Long time, no post! I'm back with an easy, DIY project for any of you that want a $9, convenient cell phone mount for your car. Picture heavy post ahead. Scroll to the bottom for a video of the finished project!

I used to stick my cell phone in my cup holder and manually attach the charger and audio cable every time I entered my car. This got messy and old fast, and the wires weren't having it. After about a year, both the USB micro cable and the audio cable stopped working. I also found it unsafe to drive and have to look down at my waist level to check directions or incoming notifications. Most normal car mounts wouldn't work since my air vents are weirdly shaped and I didn't want a suction cup windshield mount blocking my view of the road. Plus, they're kind of ugly.

A friend introduced me to magnetic cell phone mounts which are way more convenient and unobtrusive, but cost more than I'm willing to pay for a bunch of plastic (that's the cheapest, complete kit on Amazon by the way). Besides, how can I turn away a fun, DIY project?

To make your own, you will need the following:

1. Car Charger: I used one I already had - $0

2. Basic Magnetic Cell Phone Mount: eBay has a bunch of them. I picked the cheapest one - $4.89

3. Gooseneck: More flexible than a normal plastic hinged mount. I originally wanted a USB goose neck so the charging cord and the mount neck could be the same thing, but none of them were thick enough to hold a cell phone - $4.00

Optional: 

- I also bought a retractable USB micro cord so I can move the phone around and still have a tidy cable when I throw it back on the mount. 

- Tasker will allow the phone to automatically turn on the Car Home app and Bluetooth. If you want a free alternative, check out on{x}.

Total Cost: $8.89 - This is the bare minimum.

Here's the mount:

Now this is sort of where I cheated. I had an adapter 3D printed to mount the gooseneck to the car charger. You can purchase this part from Shapeways here. 

Obviously, not everyone will be able to get access to a 3D printer. The alternative is to clamp and screw on/glue the neck to the actual body of the charger, or just spend another $10 and buy a dedicated gooseneck mount (thus defeating the purpose of a DIY). Or if you're lucky, you can find someone with a MakerBot to print it for you.

Rip the neck off of the suction cup and dip it in super glue before pressing it into the plastic.

Now you have your basic construct.

Rip off the 4 tabs on top of the mount and sand down the plastic to get a clean, flat surface. Place the magnet on top and outline the magnet to mark out the excess plastic.

Use a dremel to cut off the excess plastic. Re-sand down the surface to remove and plastic burrs.

Stick the magnetic disk onto the mount. 

The USB charger, though it is labeled and advertised to output 2.1 amps, does not actually output that amount of current for non-Apple devices. I'm not sure why, but jumping the middle two pins allows the charger to output enough current to fast charge your Android device.

To make the modification, dismantle the charger. Unscrew the tip, pull out the spring and pop off the metal face using a flat head screwdriver. The two halves should come apart pretty easily after that.

Jump pins 2 and 3 (the middle two) using either a blob of solder or using actual wires. The other side is a bit tight so I dropped a blob right into the crevice between the transformer and the back of the USB port.

Tested it out before reassembling. Yay, AC charging current! Be advised, the listing on Amazon doesn't indicate that this charger can only output 2.1a total, not each.

Drip some superglue into the adapter and push the charger through. Let the glue set before messing with the gooseneck.

And there you have it! A cheap, flexible, magnetic cell phone mount.

Here's how it looks in the car:

The automation is done via a Tasker script found here. You can download it and load it into your own phone if you already have Tasker. Basically, when it senses a change in magnetic field by being mounted on the magnet (if your phone has a compass, then it should be capable of this), it will automatically turn on Car Mode, Bluetooth to connect to my stereo, and activate another Tasker profile that will read my texts to me as they come in. 

Here's a short video showing the automation and mount in action. Available in HD. I can't figure out how to auto load HD content without reverting to AS2 embed codes.