Today's Lesson: USB power

Posted by 9449505 on

While Quinn's out doing his thing, I thought I'd pop around and post something.  Today's lesson is how to install a USB port in your car.  No, it's not going to make your old-ass stereo play MP3s.  Then why?  Because I hate carrying around chargers and crap.  And because it cost me less than 3 bucks to do. Well, maybe I lied about the whole MP3 thing.  I'm using this to power my MP3 player, so I can hook it up to the AUX in of my deck.  Yes, it does play MP3 CDs, but quite frankly, I don't feel like burning a new CD every time I find a new song that I like. Anyway, here's what you'll need: Lighter to USB adapter - I got mine for 2 bucks on clearance from Radio Shack The Source. A length of 18 gauge wire - This really all depends on how far you are from a 12v source. Soldering stuff - Most of you should have this on hand. You may not be able to find the same one that I've got, and some of these things aren't cheap.  So here are some pointers. How to choose a USB power adapter: Do I have to smash it open? Look for one that comes apart easily.  The one that I found works great for that.  I bought two for that reason alone.  Good signs are if you see a screw somewhere, or if you know that it just clips together.  Avoid ones that are glued, or worse, epoxied. Will it light my car on fire? Make sure that it can handle any power draw that you can throw at it.  Normal USB spec allows for half an ampere per port.  If you want to charge your stuff faster, or plug in multiple things, make sure it can at least handle that. Can I put it back together? Two things here.  I did't feel like using an extra enclosure to protect the circuitry.  If anything happens, you do not want it to short out on anything.  Secondly, it often means you can reuse parts to secure it to your car for a clean, not crap look. Could I have spent this money on something better? Cheap and cheerful is the key here, folks.  If the sales staff tries to sell you the $10 adapter, don't bother.  Just order something from China.  It's the same crap anyways. Let's take a look at the one that I picked up, shall we? [caption id="attachment_8060" align="alignnone" width="600" caption="It's a spaceship!"][/caption] Unwieldy looking thing, right?  Well, let's compare it to the criteria. [caption id="attachment_8061" align="alignnone" width="600" caption="I've decided to use pink today. I'm not sure why."][/caption] It's got screws!  That means it's coming apart easily and cleanly.  It handles 2 amps worth of power, so I can charge the MP3 player during a road trip (while playing music!  YAY!).  Being able to put it back together isn't something that I could readily figure out at the store.  That's the only gamble.  However the presence of screws holding the main thing together was a good sign.  It was two bucks, which fulfils the budget requirements.  So either way, keep a look out for any of these remaining in stores.  They're quite ugly, so they might not sell too quickly, if they haven't sent stock back to the warehouse. Assuming that you've got the same one as me, let's get it apart.  Two screws, a twist, and some disconnecting later, you should get this. [caption id="attachment_8062" align="alignnone" width="600" caption="No, seriously, two actual screws, screwing off the little ring on the left and snipping a couple wires."][/caption] We're really only interested in the USB module on the lower right.  It's not unwieldy anymore!  I reassembled the rest, and put it aside for any other projects I may end up needed such parts for.  Remember, it's the environmentally sound thing to do! Thankfully, there was no glue holding any of this unit together.  Everything was held together by screws or friction.  You can use your fingernails, and slowly work the face out of the 'barrel' part.  Pull that apart, and you should end up with this: [caption id="attachment_8065" align="alignnone" width="600" caption="Don't break any of this."][/caption] At this point, you can feel free to do things like lop off that ring on the barrel part of the housing.  Also, since you now have access to the PCB, solder on your new power leads.  (Actually, if you're following along, stop doing this here, and just read.)  I highly recommend getting rid of the existing wiring, and soldering directly to the board.  By having one piece of wire from the power source to the unit, you avoid having a lot of ugly (and non-flexible) splices. One key element of this is 'faceplate' of the USB ports is a separate piece from the body.  This is what makes this such a great candidate for doing this.  It turns out that the inner diameter of the barrel is 7/8".  You can use this to your advantage to mount this on a flat surface for a pretty OEM looking installation.  (Assuming the colours and stuff match up, of course.)  There are two locator pin type things that you will probably have to file out openings for as well if you're going to surface mount this.  Not a huge deal.  Sandwich the panel between the faceplate and the barrel, and it should look something like this once assembled. [caption id="attachment_8066" align="alignnone" width="600" caption="But far less cardboardy."][/caption] I have mine buried under the console with some cables poking out, but if you're surface mounting, DO NOT HAVE IT POINTED AT YOUR FACE.  Whoever designed this thing put a really bright LED on the front of it.  It will seriously suck if you're driving at night with that glaring into your eyes. Some suggested mounting points include:
  • In the back of your center cubby thing
  • In the center console under the arm rest
  • On that panel under the steering wheel
  • In the glovebox (but not like if it's like the AE86 glovebox)
Just make sure when you find a spot you like, do a couple dry fits to see if you have the clearance behind the panel to install it.  Personally, I just ziptied it to the lighter harness.  Turns out there's lots of room up under that particular panel of my car.  I didn't want to pop any holes in the interior just yet, either. The Next step is to connect to power.  I hope you heeded my suggestion up there about just reading and then doing.  This is where you want to figure out how much wire you need to connect to power and ground.  Now go back  Mine is hooked up (quite sketchily) to the lighter itself.  It turns out that Nissan lighters can be disassembled and the power and ground leads can be inserted into places.  If you've got a 12v power distribution block for aftermarket electronics somewhere, that's where I'd suggest getting power from.  Then ground to chassis, and be done.  Don't do what I did.  Do something proper. [caption id="attachment_8074" align="alignnone" width="600" caption="No, it's not perfect. No, I don't care. It works."][/caption] All that's left is to reassemble everything.  Hopefully there aren't any leftover screws.  Once that's done, go out and enjoy whatever it is that you're hooking up to your new found power source.


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