For Christmas I got a new Otterbox case for my Galaxy Note 4. Since the Otterbox is significantly bigger than my old case, it forced a a revision of my car Galaxy Note 4 Car Dock.
Rather than simply increasing the size of the Car Dock, I set out to add several new features:
- Integrated QI Wireless Charging
- 4G LTE Cellular Amplifier
To add Wireless Charging to the Galaxy Note 4 all you need is a QI Sticker and a QI compatible wireless charging pad.
The QI Sticker I chose includes a separate antenna for NFC. This is important because many cheaper QI Stickers render the NFC inoperable. The QI Sticker installs inside the phone between the battery and the back cover.
The QI charging pad I chose is pretty much the cheapest one out there. It is a single coil design so the phone placement is critical. I found that the phone has to be in the exact perfect spot or else it will not charge at all. Despite perfect placement, I find this charging pad to be extremely slow. Hopefully it will keep up with my in-car entertainment and GPS usage during long trips.
Back to the Drawing Board
My original Galaxy Note 4 Car dock was designed in Solidworks, revising the 3d models was easy. For the second revision I simply measured the new Otterbox case with my calipers and revised the dimensions for the Galaxy Note 4 model I had created previously. Thanks to the equation based design constraints, the brackets automatically scaled to fit the new phone dimensions.
4G Signal Amplifier
I’ve found T-Mobile reception to be pretty spotty, so I wanted to add a signal amplifier to help improve the range.
The signal amplifier kit consists of three parts:
- Exterior Antenna
- Interior Antenna
The Wilson amplifier kit I chose supports 4 signal bands and appears to actually have some clever design features including feedback-loop detection. I was pleasantly surprised by the build quality.
The product seems to work fine, and the number of bars on the phone definitely goes up. Unfortunately, if the phone is only getting 2G/3G, then after amplifying it still only gets 2G/3G. I suspect this may be because some of the cell towers don’t actually support 4G LTE. I wasn’t expecting miracles, however I’m not sure its worth the price.
Final Assembly with NFC
I printed and assembled the new car dock design on my Ultimatker 3d printer and had the new assembly up and running in just a few hours, not including the shipping time for the various products.
NFC was added using a Samsung Tectile. Using the Xposed “NFC LockScreenOff Enabler” module I was able to configure the phone to automatically unlock when placed in the dock.
On its own, the NFC works great, but since NFC and wireless charging use similar frequencies, the charging pad drowns out the NFC signal. The next revision of the dock will use a bluetooth connection to determine the lock status instead.