DIY Wireless Charger + NFC Dock for Your Car

It's pretty amazing how much easier it is to use our smartphones as GPS these days! But anyone who does this regularly will know it really drains your battery, so you always need to keep it on charge when you're driving.

This project will show you how to turn any in-car phone holder into a DIY wireless charger and NFC dock! It means all you need to do is clip your phone in place and you're good to go... super simple! No plugging and unplugging your charger cables each time. Plus combining using NFC tags means your phone will load up the app you want on demand — we used maps for this, but a driving playlist might come in handy :)

This idea started a couple of weeks ago when Juan and Tom on the sugru team were talking about where it would be handy to have wireless charging for their phones. They decided building it into a car would be awesome, so they challenged Jude (remember the Oyster card hack?!) to make a DIY in-car charging system.

Here's what Jude dreamt up...

Step 1: Get Your Kit Ready

For this project you'll need:

— car phone holder and USB cable and power/cigarette port (or USB to USB if your car has one of those)

— an NFC tag (self adhesive)

— Wireless charger loop and PCB (Combined)

— pack of sugru (black)

— your cell phone (we've used a Nexus 4)

— scalpel

— soldering iron

— coffee stirrer - *cough* liberated from a corporate coffee bar

— also you'll need some paper, a pen, some sticky tape and some tissue paper

Step 2: Modify the Wireless Charger Loop

Reason we did this is so that your phone sits flush on the induction loop.

— unsolder the connection to the PCB

— thread the wire through the hole in the centre

— and re-solder back in position

ta-dah!

Step 3: Find the Range of Your Wireless Charger

This seemed like an easy way to find the tolerance of the wireless charger in relation to your phone.

— Tape up the now re-soldered wireless loop to a piece of paper

— Plug it in

— Slide your phone up, down, left and right over the wireless loop to find the tolerance of your phone's charging radius. (Sadly up, up down, down, left, right, left, right won't unlock a cheat here)

— Mark the edges and mark the limits

— Using your sketch to position the wireless loop onto your car phone holder

— Slide your phone in to position to ensure it charges when docked

Step 4: STOP... Sugru Time! :)

sugru's perfect for this project because it fills weird gaps, is non-conductive (that means it's insulating folks!) plus it's pH neutral so it won't eat your PCB like some silicon caulks can.

— open your sugru and roll into two thin sausages (roll it on paper to keep your desk nice and clean and stop fluff and nonsense getting rolled into it)

— apply one sausage on the backside of your wireless loop (matching the shape of your phone dock)

— apply the other sausage around the edge of your PCB

— gently, but firmly, press everything together, securing it onto your phone dock, as shown.

— let the sugru squidge out a little as you press (next step will explain why)

Step 5: Smooth the Sugru

— Here we're using a coffee stirrer we *cough* liberated from a corporate coffee bar that rhymes with megabucks ;) FYI - they make great sugru shapers

— For a smoother finish usually we'd say use a little soapy water, but in the interest of your PCB, steer clean of water here, just give the sugru a gentle rub with your finger to smooth the surface.

— Leave the sugru to cure for a full 24 hours before using.

Step 6: Position and Program NFC Tag

— Switch on your NFC reader on your phone (somewhere in 'settings' on Android)

— Wiggle around the NFC tag on the back of your phone to find it's NFC reader

— When it finds it you'll see a message saying 'empty tag found'

Program the NFC tag - We used CYNICALifornia's great 'ible here to program ours

We set our NFC to:

+ switch on wi-fi (helps with GPS positioning)
+ switch on data
+ switch on GPS
+ load google maps
+ whatever else you want... maybe a driving playlist :)