Rear View Mirror Power Supply by chiwi

Last crawled date: 3 years, 1 month ago

This is a mounting & case for a step down "buck" convertor to supply USB voltage to a powered Rear View Mirror in my RAV4.
I recently replaced an auto dimming rear view mirror in my Toyota RAV4 with a third party powered rear view mirror (specifically a NikoMaku AS-3 Pro 12" rear view mirror with dash cam & rear view camera - link at end). As most (all?) third party mirrors use USB or 5V, the fitting a buck convertor is needed.
The kit is powered by a cigarette lighter adaptor which plugs into a USB socket on the mirror via a long, long, really long... (did I mention that its long?) cord.
The simple solution would just be to run the cord from the rear view mirror back to the cigarette lighter socket or otherwise hard wiring it into the vehicle wiring. BUT doing so could have negative aspects (occupying the only cigarette lighter outlet, voiding vehicle warrantee, unknown side effects of tapping into electrical circuits etc etc). On top of that, there's already a 12V feed right where its needed AND we of course have access to 3D printing.
The RAV4 has a two piece plastic cover (a large U-shape & an insert) which hides the electronics and the base of the rear view mirror mount. I've designed a "Blanking Plate" to replace the insert. I chose this method after having ongoing issues with my customised Mirror Mount constantly deforming in the heat. Hopefully the fact that the Blanking Plate has no nearby metal fittings will make it less affected by heat within the vehicle.
The PSU Shroud is simply a small cover to house the buck convertor. It uses 2x M2 bolts & nuts to fasten it to the Blanking Plate. I had these left over from another project and simply cut them to length.
I did attempt to source a proper socket to interface with the Toyota fitted wiring plug but was unsuccessful so just settled for a piece of solid core twin with the bared ends shoved into the connections. I secured the wire in place with a piece of electrical tape. At a guess, I suspect that the plug is proprietary for whatever brand mirrors Toyota uses in its cars as I wasn't able to locate it on the web.
I connected the buck convertor to the mirror with a really short USB lead. Its been a month so far and everything seems to work well. Links for all items of equipment follow.
https://www.amazon.com/gp/product/B081ZVH35J/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
https://www.aliexpress.com/item/32955045499.html?spm=2114.13010708.0.0.347f4c4d1Bb9OW
https://www.aliexpress.com/item/10000315951480.html?spm=2114.13010708.0.0.3a994c4dMqVA8f