Add powered USB ports to your car, including one on the top dash for windshield mounted items (a yaris in this case but electronics applicable to all cars)

This will show you how to add powered USB ports to your car (yaris in this case) and wire one of them to power a phone from the dash to use it as a GPSin your windsheild

I will show you how to

1- add a usb power supply that will be coming out from the dash to power my phone that I use as a GPS when it is attached to the windshield

• running the wires
• powering them (see number 2)

2- add usb ports that can be use to charge directly any usb powered device from the two little unused rectangles under the parking break stick near the current 12v supply

• making a 12v to USB power circuit (both the complete DIY and the hack-up-an-existing-device ways)
• connecting the device to the power supply
• making a face plate

Materials needed (this list is for the ones where you don't make your own circuit, the DIY circuit will come later)

• small snips (to cut tin plastic and wires)
• needle-nose pliers
• a flash light
• Hot glue gun
• Screw drivers (or whtever tool is needed to dismantle the adaptors)
• 1 inch or 3 of an inch fuse container (depends on the device you are using)
• soldering iron
• solder (and flux if you have some, but if you don't no need to buy it, fresh solder added is enough to re-flux old boards)
• Ethernet cable (easiest way to thread many wires at once and they are stiff enough to be easier to thread in the car)
• USB port (can be recovered from any device or bought new or you can skip this and solder directly to your usb cable, not recommended due to the type of wires used in usb cables)
• snap connectors x 10
• wire (2 different colours can save you lots of headaches)
• a usb to 12v adaptor

For the DIY circuit, replace the USB to 12v adaptor with the following:

• a L7805CV voltage regulator, part number 497-1443-5-ND from Digijey
• a 220uf 16v Capacitor, part number P5139-ND from Digikey.
• female USB ports times the number of ports you want (2-3 would be normal), Digikey number AE9923-ND
• if you choose to add an LED, you need an LED and an appropriate resistor for 5V. This depends on your LED's rating. Any LED will do, here are the values for the most common LEDs : 1.2v = 220ohm, 1.6v = 180ohm, 2v = 180 ohm, 2.2v = 150ohm. If you have a strange LED or want to make it brighter, please use this resistor calculator.

Step 1

Step one- wiring the car. I used an Ethernet cable as it is rigid enough so that you can twist it to make it point in different directions when you are pushing it where its out of reach and soft enough to bend around corner and such. Cutting off the tip you will be pushing through will make things easier because it will be smaller. Closing it off with hot glue so that it can't get hooked on things as you push is not a bad idea either, but you can do it without doing this (I had not tough of this when I originally did it)

I removed the paneling in the order show in the picture with numbers on the panels. It takes a bit of patience, a good flashlight (if you have one that goes on your head, it will save you lots of trouble) The red line shows approximately where I wired it. long needle-nose pliers can bu useful too for reaching. Make sure the car is OFF.

Comments

[an4rk]

to author... does the 7805 give off any heat? If it does is it a small enough amount that I wouldn't need to include a heatsink?

[julienrl]

the one I used has alot of heat, the integrated heatsink is enough for it to work, but adding an extra one would not be a bad idea, it has been reported to help out, and just about any computer heatsink with a screw-hole will work. If you got for a slightly more expensive transistor (like 1-3$ more) you can get a much more efficient one that will give off almost no heat.

[an4rk]

can you suggest a more efficient one?

[julienrl]

Certainly, these TSR-12450 are much more efficent. http://www.tracopower.com/fileadmin/medien/dokumente/pdf/datasheets/tsr1.pdf However, like other highly efficient ones, they have a lower maximum amperage, so you should use a 1amp fast blowing fuse (this means 2 ports in use MAX and even that depends on your device). They are also much harder to find, I could only find them here for 10 euros each. http://www.conrad.de/ce/ProductDetail.html?hk=WW2&insert=U1&WT.mc_id=epro&productcode=156673&zanpid=1402519872037980160 A heatsink on L7805's is definitely a great very viable and safe option, but if you can get your hands on something like the ones I pointed to, then all the better for you! :) good luck!

[Quantinuim]

All wel and good but wat i want 2 kno is how 2 hotwire a car anybody kno? ( 4 scintific purposes of corse)

[Tobita]

For scientific purposes, telling you that essentially hot-wiring is crossing the wire from the battery's positive terminal to the ignition. But to REALLY hot-wire a car, you'd need a way to start all other essential systems, so fuel pump, oil pump, ECU in a modern car, etc. etc. and there is also the matter regarding the alarm system also that regarding actually getting INTO the car, good luck and take care in your "scintific" endeavors.

[jkiym]

just a thought on running wires, if you tape a piece of stiff wire to the end of your cable you can use that to push it through the fire wall of the car or into places that you cant reach. that way you don't need to run stiff cable.

[julienrl]

kind of like threading a needle; my next project does require that I go through the fire wall, but this one did not. The ethernet cable was nice because it is stiff enough to stay in place but soft enough that i could wiggle it around until it finally decided to pass where I wanted it to :p

[rosscutts]

are you wiring this into your 12v line in parallel so you can still use your cigarette lighter for other devices? And how are you connecting this into your 12v line, are you splicing it in? Thanks!

[julienrl]

Yes it is in parallel with the 12v so the cigarette lighter still works. I made a macguiver plug to make a T splice where the cable clips into the 12v cigarette socket, but you can do it directly in the wire if you want. I did not include that because it was actually REALLY half-a**ed on my part.