Since I’ve ripped most of this car apart, and I plan to keep it a long time, I figure I might as well make the interior completely custom as well. One of the first things I needed to add was a wireless phone charger.
The plan ultimately is to customise the centre console to accept an integrated double-din head unit with a touchscreen that will allow me to access the web interfaces for the inverter and battery management system and make tweaks on the fly. This customisation process is quite involved and requires lengthening the heater cables.
Communicating with all the different bits of the car means everything needs to be on a shared Wi-Fi network. I thought about installing a 5G wireless modem/router with its own SIM card, but this adds cost and complexity that I don’t – yet – need. Long run I might want to be able to remote control aspects of the car from my phone but my phone will do as a a hotspot for now.
So I don’t need the phone to be visible from the driving position, but I do need to make sure it stays charged. And ideally I want it to turn on the hotspot automatically when I get in the car. That sounds like a design brief.
Wireless Charging
Turns out I actually had a cheap wireless charging module from a previous project that never got finished. This takes a 5V USB input and pumps out juice through a flat coil to be picked up by the phone – in this case a Samsung Galaxy S21.
Since the phone doesn’t need to be visible from the driving position, I figured I’d drop it down to the driver’s left into the centre console near the handbrake. In fact, since I don’t need an ash tray, it can replace that. For now it will sit proud of the existing plastic but long run it will be integrated, when I take the console out to adapt it for the double din stereo.
Design
I jumped into Fusion360 and after a few iterations I had a cradle I could print that would hold the phone through corners.
The charging coil sits in the centre and the electronics go below. The holes allow the cradle to be screwed to a mounting bracket beneath – also printed. A thin sheet sits over the coil, protecting and hiding the electronics.
Long run, the mounting block will sit flush with the end of the coin tray. This is just a temporary version. The design also needs tweaking to separate the electronics from the cradle so that I can update it easily to fit a different phone if required. But this will be fine for a couple of years.
The cradle is now installed in the car and working, though the wiring is yet to be fully integrated – that’s a job for when the centre console comes out. The white dot in the middle is an NFC tag that enables the mobile hotspot via a Bixby routine.
